Category: What’s Up

M63: “The Sunflower Galaxy”. Image credit: N.A. Sharp/NOAO/AURA/NSF. Click to enlarge
Greetings, fellow SkyWatchers! It may be raining all over the world, but when the skies do clear there will be plenty to explore as we take a look at bright star systems, distant galaxies, globular clusters and astronomy history. So turn your eyes to the skies, because….

Here’s what’s up!

Monday, May 15, 2006 – While we have a short time before the Moon rises, let’s head towards the stars and revisit the fourth brightest in the sky – Arcturus.

Located some 37 light-years away, the “Watcher of the Bear” was one of the very first stars to be seen during daylight in 1635. It achieved public fame when light from Arcturus activated a photoelectric cell which actuated a relay to turn on floodlights to open Chicago’s “Century of Progress” Exposition in 1933. This nearby star was chosen for the honor because the light reaching Earth that night was thought to have left Arcturus during Chicago’s 1893 Exposition. Here’s to guessing you couldn’t see Arcturus once the lights were on….

But keep your lights off and your eyes on the skies as we explore four celestial “neighbors” of Arcturus. About a fist width east, you’ll see four stars arranged roughly north/south. The northernmost is 4.6 magnitude Xi – a very pretty double with yellow primary and disparate orange secondary. The next star south is 4.7 magnitude Omicron, followed by 4.9 magnitude Pi to the southwest. Pi is a double with a closely matched magnitude companion trailing it to the east. Keep heading south for Zeta – also close to being a matched set. But, beware… It takes at least a larger scope and high magnification to split this pair!

Tuesday, May 16 – With plenty of time before the Moon rises, let’s revisit a galaxy very similar to our own Milky Way – NGC 2903. Located less than two degrees south of Lambda Leonis, this magnificent 9.0 magnitude barred spiral can be spotted with binoculars from a dark location, and is easily seen in a small scope.

While NGC 2903’s size and central bar closely resemble our own galaxy’s structure, the Hubble Space Telescope crossed the 25 million light-year gap and found evidence of young globular clusters in its galactic halo – unlike our own old structures. This widespread star forming region is believed to be attributed to the gravity of the central bar. Small telescopes will show the bar as a lateral concentration across the central structure, while larger apertures will reveal spiral arms and condensed regions of innumerable stars.

Want to try something new? How about the exquisite 9.6 magnitude globular cluster – NGC 5634. Found about halfway between Iota and Mu Virginis and almost due south of Phi, what makes it special is its environs. The little globular shows half its size in smaller scopes, but shares the field but that half with an 8th and a 12th magnitude star. This gives it the appearance of a trinary star system!

Wednesday, May 17 – Today in 1835, J. Norman Lockyer was born. While the name might not be widely recognized, Lockyer was the first to note previously unknown absorption lines in the Sun’s spectrum while making visual studies in 1868. Little he knew that he had correctly identified the electromagnetic signature of the second most abundant element in the universe – helium – an element not discovered on Earth until 1891! Also known as the “Father of Archeoastronomy,” Sir Lockyer was one of the first to note the astronomical nature of ancient structures such as Stonehenge and the Egyptian pyramids.

If you would like to see a helium rich star, look no further tonight than Alpha Virginis – Spica.

Also on this day in 1882, a sun-grazing comet was discovered on photographs of the solar corona taken during a total solar eclipse – but the mysterious comet has not been seen since.

Thursday, May 18 – Before the Moon rises tonight, let’s locate Iota Centauri – another “bright star and galaxy” view. NGC 5102 is a 9.7 magnitude lenticular galaxy which displays a brilliant core. The core region is about all you will see with a 2.9 magnitude star so nearby! A challenge? You bet…

On this day in 1910, Comet Halley transited the Sun, but could not be detected visually. Since the beginning of astronomical observation, transits, eclipses and occultations have provided some very accurate determinations of size. Since Comet Halley could not be spotted against the solar surface, we learned almost a century ago that a cometary nucleus had to be smaller than 100 kilometers in diameter.

Would you like to get a grasp on that concept? Wait until the Moon rises tonight and revisit the most prominent crater of all – Copernicus. In a study done by Shoemaker, this ancient crater was proven to be formed by a gigantic impact. Feature after feature so closely resembles geological impact craters on Earth, that we can say with complete certainty this crater was formed by a large meteoritic body. And just how large is crater Copernicus? Oh, about the size of a certain famous comet’s nucleus – 100 kilometers…

Now let’s head for Omega Centauri. At magnitude 3.7, NGC 5139 is one of the few studies in the night sky receiving a Greek letter despite being decidedly “unstarlike!”

Recorded by Ptolemy as a star, given the designation “Omega” by Bayer, and first noted as non-stellar by Edmond Halley in 1677, J.L.E. Dreyer went on to add three exclamation marks (!!!) to his abbreviated description after including it as entry 5139 in the 1888 New General Catalogue. As the largest globular cluster in our own galaxy, this 5 million solar mass “star of stars” contains more matter than Sagittarius A – the supermassive black hole on which the Milky Way pivots. Omega’s mass is greater than some dwarf galaxies. Of the more than thirty galaxies associated with our Local Group, only the Great Andromeda possesses a globular (G1) brighter than Omega!

Friday, May 19 – Tonight let’s begin by locating the constellation Canes Venatici as we pick out the “Sunflower Galaxy” – M63. Located about a fist width southwest of M51, you can sometimes spot it by scanning the area midway between Alkaid and Cor Caroli.

Originally discovered in 1779 by M?chain, bright M63 is located about 37 million light-years away and believed to be part of a group of galaxies including M51. To binoculars, M63 appears as a faint misty oval, but larger scopes will reveal the galaxy’s spiral arms as a grainy background – brightening considerably towards the center. The most interesting feature of M63 is its arm structure. Most typical spiral galaxies contain two or three distinct arms, yet this structure is multiple – showing short spiral arcs reminding many observers of a “celestial flower.” Studies of M63 reveal that the galactic material at the edges of these arms is moving much faster than normal. Given the amount of visible matter, this additional rotational velocity indicates the presence of significant amounts of dark matter in its overall structure.

If you’re in the mood for a challenge, why not try faint globular cluster – NGC 5466. Located in Bootes, NGC 5466 gives a splendid view in larger scopes. – showing a “pin-cushiony” distribution of its fainter stars. Small instruments might be able to pick this one up on a dark night. The cluster is 52 million light-years away – a value very similar to that of M53 and neighboring globular cluster NGC 5053. To locate NGC 5466, start at M3, about halfway between Arcturus and Cor Caroli. Head due east about five degrees past a lone 6th magnitude star.

Saturday, May 20 – Early evening dark means a good time to look for “the Owl and the Edge-On.”

Start with Beta Ursae Majoris – southwestern star of the Big Dipper. About a finger-width between it and Phecda to the southeast, you’ll catch the 10.1 magnitude Edge-On galaxy first seen by Pierre M?chain on February 19, 1781. Although it was later verified by Charles Messier, it didn’t formally enter the Messier catalog until 1953 when Owen Gingerich entered it. Despite being faint, M108 contrasts well on a good dark night sky and larger scopes will make out irregular patches of detail.

Less than a finger-width further southeast, you’ll spot M97 – the Owl Nebula. But let’s ask a tough question: Which came first, the Owl or the Edge-On? According to Owen Gingerich’s research, the Owl (M97) was discovered by Pierre M?chain three days earlier than the Edge-On – and what an accomplishment that was! Many observers cite M97 as one of the most difficult of the Messier studies to detect – especially through the kind of contrast-robbing skies found near larger cities. Pollution!

The “Owl” gets its name for the vague gray-greenness of its light, and the two curious voids visible through larger scopes. These voids are thought to be the result of looking at a globe of nebulosity whose lowest-density poles lie at an oblique angle to our line of sight. The material making up M97 and the light causing it to glow are associated with a high surface temperature central star in the last stages of life. At the center of M97 is a faint 16th magnitude dying star.

Sunday, May 21 – Are you ready for something new? Then let’s start by locating the two northernmost stars of the Big Dipper – Dubhe and Megrez. Now imagine that these two bright stars are the base of a pyramid. Use lowest power and center at the apex of this pyramid to the north. There you will see a fine, mid-sized spiral galaxy – NGC 4125. Average scopes will see a stellar nucleus in the 9.8 magnitude structure, along with an expansive core region and faint spiral extensions. A “Missed-Messier” perhaps? You bet!

Something old? Return to Omega Centauri and the 7.0 magnitude, almost incomprehensibly structured galaxy NGC 5128. It’s otherwise known as radio-source Centaurus A! NGC 5128 is easily found halfway between Omega and Iota Centauri.

And now for Moon rise…

In 1961, United States President John F. Kennedy launched the country on a journey to the Moon as he made one of his most famous speeches to Congress: “I believe this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth. No single space project in this period will be more impressive to mankind or more important for the long-range exploration of space…”

While the Apollo 11 landing site is hidden behind the terminator tonight, it is still possible to see another: that of Apollo 15. Locate previous northern study crater Plato and look due south past the isolated Spitzbergen Mountains to comparably-sized Archimedes. Spend a few moments enjoying Archimedes’ well-etched terraced walls and textured bright floor. Then look east look for the twin punctuations of Aristillus and the more northern Autolycus. South of Aristillus note the heart-shape of Paulus Putredinus. There you will see Mons Hadley very well highlighted and alone on its northeastern bank. Power up to see that the Mons Hadley area includes a cove known as the Hadley Delta, and there on that plain just north of the brilliant mountain peak is where Apollo 15 touched down.

Be aware that Uranus is also very nearby and will be occulted by the Moon! Check IOTA for specifics in your area.

May all your journeys be at light speed… ~Tammy Plotner with Jeff Barbour.

Download our free “What’s Up 2006” ebook, with entries like this for every day of the year.

Fra Mauro. Image credit: Fra Mauro. Click to enlarge.
Greetings, fellow SkyWatchers! “There’s a bad Moon on the rise”… But that won’t keep us from viewing historic lunar areas such as the captivating Fra Mauro and catching bright clusters and double stars! Come along and join us a we take a look at what can be seen this week, because…

Here’s what’s up!

Monday, May 8, 2006 – A little more than 35 years ago, the Apollo 13 crew was on a mission to land in the Fra Mauro highlands. Although a near-disaster kept the crew from completing the mission, Apollo 14 carried out the plan less than a year later. Tonight we will be able to see this landing area on the lunar surface. Along the terminator to the south, you will see a dark expanse known as Mare Nubium. On its northern shore and near the terminator’s center, you will see an inlet of small shallow craters. The brightest of these small rings is crater Parry with Fra Mauro appearing larger and shallower to its north. Power up! Fra Mauro has a long fissure running between its north and south borders. At the northern crater edge you will see the ruins of an ancient impact. Appearing as an X, it definitely marks the spot of this successful lunar landing.

Tonight let’s use binoculars to hunt down a large open cluster – Melotte 111 – northwest of Arcturus. Like other visible clusters such as the Hyades, Pleiades and Praesepe, this Coma Berenices star cluster has a place in history. Known as the “Queen’s Hair,” it was first noted by Ptolemy. In more recent times, R.J. Trumpler identified 37 stars in Melotte 111 that share common movement. This discovery revealed the Coma Berenices cluster as a true group and not just a random collection.

Satellite observatories, like ESA’s Hipparcos, show us the members of Mel 111 are located around 288 light-years distant, making it one of the closest clusters in the heavens. Of the 37 stars identified by Trumpler, the brightest is 4.35 magnitude Gamma and the faintest members range to magnitude 10.5. Of the 400 stars gathered in this region, only about 129 are not true members of the group.

Tuesday, May 9 – Today in 1962, the first Earth-based laser was aimed at crater Albategnius. While the terminator has moved well beyond its position, you can still pick it out of the jumbled landscape. Look centrally on the lunar surface for the small, heart-shaped, grey area known as Sinus Medii. Just south of it lie a pair of prominent craters, Ptlomaeus to the west and Albategnius to the east.

The Moon will also offer many features such as the fully disclosed Tycho, the incomparable Copernicus and the fascinating Bullialdus, but tonight we’ll be looking for “The Great Wall.” Start by drawing a mental line from Tycho to Copernicus, then extend that line by two-thirds the distance north. Here you will discover what looks like huge wall on the lunar surface. At 48 kilometers high and 161 kilometers long, that would be a great wall! It is nothing more than the western portion or the Juras Mountains surrounding the lovely Sinus Iridum, but it’s definitely a rather striking feature and well worth the time to look in both binoculars and telescopes. Klare nacht!

Ready for more? How about another unexpected “open” cluster? Then look at Ursa Major. The primary stars – Merak, Phecda, Megrez, Mizar, and Alioth – have their own designation. Known as Collinder 285, it was first recognized as a cluster by R.A. Proctor in 1869. The Ursa Major “Moving Cluster” is headed south and east toward a spot in Sagittarius (RA 20:24 and Dec -37). The center of Collinder 285 is located 75 light-years away and its most distant bright member is outlying Alpha Coronae Borealis. The stars in this group are very similar to those in the Hyades – giving a cluster age of roughly 750 million years. Motion studies of over 100 stars throughout the sky (including Sirius, Alpha Ophiuchi, Delta Leonis, and Beta Aurigae) all show a similar “drift” across the heavens at a speed of almost 50 kilometers per second. That’s faster than the average speed of Mercury orbiting the Sun!

Wednesday, May 10 – Tonight bright Spica will join the Moon – making a very close appearance for some – and an occultation for others! Be sure to check IOTA for details. The most prominent lunar feature will be the ancient and graceful Gassendi. Its bright ring stands on the north shore of Mare Humorum – an area about the size of the state of Arkansas. At 113 kilometers in diameter and 2012 meters deep, you will see a triple mountain peak in its center and the south wall eroded by lava flows. Gassendi offers numerous fine details to telescopic observers on its ridge and rille covered floor.

When you have finished your lunar observations, let’s revisit a fascinating double star and try a simple experiment. Center your scope on Cor Caroli and watch as the “Heart of Charles” drifts west. The warm yellow primary is a magnetic spectrum variable and the pale blue secondary makes watching this 120 light-year distant pair pure pleasure. Now wait two and a half minutes as widely separated double Struve 1702 comes into view. Now that’s finding faint double stars made easy!

Thursday, May 11 – Tonight’s lunar observations will be a challenging study worthy of larger scopes. Start by identifying previous study craters, Hansteen and Billy. Due west of Hansteen you will find a small crater known as Sirsalis near the terminator. It will appear as a small, dark ellipse with a bright west wall along with its twin, Sirsalis B. The feature you will be looking for is the Sirsalis Rille – the longest presently known. Stretching northeast of Sirsalis and extending 459 kilometers south to the bright rays of Byrgius, this major “crack” in the lunar surface shows several branchings – like a long dry river bed.

Tonight let’s go from one navigational extreme to another as viewers in the northern hemisphere try their hand at Polaris. As guide star for the north, Polaris is also a wonderful double with an easily resolved, faint blue companion. But what about the south? Viewers in the southern hemisphere can never see Polaris – is there a matching star for the south? The answer is yes. Sigma Octantis. But at magnitude 5, it doesn’t make a very good unaided eye guide.

Ancient navigators found better success with the constellation Crux – better known as the “Southern Cross” – to guide them. Two bright stars of the Southern Cross, Gacrux and Acrux, are oriented north-south and point across the pole to brilliant Archenar. Splitting the distance between Gacrux and Archenar puts you within two degrees of the rather desolate south pole of the sky. Southern hemisphere observers wishing to see a double star comparable to Polaris in appearance should choose Lambda Centauri. The difference in magnitude between components and separation are about the same.

Friday, May 12 – The Moon and Jupiter rise tonight shortly before the Sun sets. Despite lunar surface brightness, we can do some exploring. Start by identifying the grey oval of Grimaldi central on the western terminator. Just north of Grimaldi is Hevelius. It appears as a bright oval, similar to Grimaldi, but contains an off-center mountain peak. Hevelius’ north wall is broken by well defined Cavalerius, a narrow, bright ellipse with thin, black border to the east. 100 kilometers west of Cavalerius on the edge of Oceanus Procellarum are the remains of the very first successful lunar landing. It was here on February 3, 1966 that the Soviet probe Luna 9 touched down. The man-sized craft sent back panoramic television images revealing an uneven, jagged surface covered with dust. So good were the probe’s images, that scientists were able to discern small depressions and protrusions only millimeters in size.

While we’re out, let’s take a look at bright Spica – Alpha Virginis. Located 262 light-years away, 1.0 magnitude Spica glows with the combined light of four unresolved stars and has a visual luminosity 2100 times that of the Sun. As a rotating ellipsoidal variable, the four stars cause complex changes in luminosity by distorting the shape of the brightest components.

The dominant star – Spica A – has a mass 11 times that of the Sun and fluctuates in physical size as it varies in brightness. The primary star is at maximum when smallest, giving it the highest photospheric surface temperature. Spica B has a mass of 7 suns. As a spectral type B, these two components produce more light in ultraviolet due to exceedingly high surface temperatures. Spica has two distant telescopic companions – magnitude 12 to the north-northeast, and magnitude 10.5 to the east-northeast.

Saturday, May 13 – Tonight is Full Moon. By May in most areas, flowers are everywhere, so it’s not hard to imagine how this came to be known as the “Full Flower Moon.” Since northern hemisphere Earth is re-awakening after the winter season, the agricultural cycle has begun and this is also known as the “Full Corn Planting Moon.” Another name? The “Milk Moon” due to the increased productivity from cows grazing on the rapidly greening pastures. No matter what you call it, the Moon still rises majestically upward from the eastern horizon!

Just because we have a full Moon doesn’t mean we can’t have any fun. Tonight let’s explore the star in the middle of the handle of the “Big Dipper.” Its name is Mizar, but if you have exceptional eyes you may also see its companion Alcor as well! The ancient Arabs used this star as an “eye test” for warriors – if you could see both stars, you were given a horse. The names Mizar and Alcor literally translate to “the horse and rider.” If it’s not clear to you, even the slightest optical aid will separate the two, but a treat is in store for telescope users. Mizar itself is a double star. It was the very first to be discovered and photographed. In the eyepiece, Alcor appears to the east of Mizar A and B, but look for a faint star in between. It has the very impressive name of Sidus Ludovicianum and was once believed to be a planet.

Sunday, May 14 – With just a little time to spare tonight before lunacy, let’s take a look at the fine double star – Epsilon Bootes. At magnitude 2.7, Izar is easily located a fist width north-northeast of brilliant Arcturus. A “test double” for small scopes, the real limiting factor to resolving this disparate pair is the stability of the night sky. Look for the blue 5.1 magnitude companion 2.6 arc seconds north-northwest of the yellow-orange 2.7 magnitude primary.

May all your journeys be at light speed… ~Tammy Plotner with Jeff Barbour.

M53. Image credit: Credit: REU Program/NOAO/AURA/NSF. Click to enlarge.
Greetings, fellow SkyWatchers! Have you been following the comet’s trail? If not, there’s observing tips on how to locate 73/P Schwassmann-Wachmann easily. Get out your binoculars or telescopes as we prepare to journey to the Moon and beyond ths week – because…

Here’s what’s up!

Tuesday, May 2 – UPDATE: For those interested in the whereabouts of the C-component of comet 73/P Schwassmann-Wachmann, look no further than Hercules. As the week opens, you’ll find it cruising through the center of the “keystone” (see SkyHound’s map) and easily visible to small binoculars under less than optimal conditions. Be sure to let the constellation rise at least to the upper third of the sky before attempting observations and enjoy!

For early evening viewers, tonight’s Moon provides a great opportunity to visit telescopically with some smaller features located within the fully disclosed Mare Crisium area. Look for two bright mountainous areas near the terminator on the central western border of Crisium. These two regions include the Olivium and Lavinium Promontoriums. Voyaging across Crisium’s smooth floor toward the east, you will see the small punctuations of Craters Picard to the south and Pierce to the north. Try to follow these features over the lunar cycle and see how many nights you can continue to see them.

As the Moon sets, let’s have a look at three entirely different studies around the constellation Corvus, the “Crow.”

The most recognizable shape of Corvus is an irregular box of visible stars southwest of Spica. The southeastern-most star is Beta Corvi. Look around two finger-width’s south for faint star SAO 180965. By aiming your low power scope or large binoculars there, you will find 8.2 magnitude globular cluster M68 to the northeast. The several hundred thousand stars comprising M68 spread out over a region 110 light-years in diameter. Located about 35,000 light-years away, it’s a nice challenge.

Now head for the northeast star in the box, and you notice that it’s a nice visual pair – Eta and Delta. Around two finger-widths southwest will put you in the area to find planetary nebula NGC 4361. This fairly large, irregular, 10th magnitude planetary has a faint central star surrounded by a “square fuzzy shell” of nebulosity. Notice how it appears to flare outwardly as the eye moves about the field of view. Perhaps there’s more to this planetary than meets the eye!

To locate our next study, just head 11 degrees (very slightly more than a fist width) due west of Spica to locate the Sombrero Galaxy – M104. Showing surprising structure through binoculars and small scopes, this 8.3 magnitude, near edge-on spiral is one of the most massive known. Mid-sized scopes should look for M104’s large central bulge and extended tightly wound arms. Viewers with large aperture will easily see the dark lane breaking across the galaxy’s equator through the bulge of the nucleus.

Be sure to look for a striking “Scorpio-shaped” asterism of equally bright stars just northwest of the mighty “Sombrero!”

Wednesday, May 3 – Tonight the Moon is the prominent sky feature, so why not venture to the surface and visit one of the oldest features left on the visible lunar side? Start by identifying two prominent craters in the southeast quadrant – Metius and Fabricus. While viewing the area around them, note that Fabricus’ walls actually intrude on Metius – pointing to a younger age of formation. Around Fabricus, but not including Metius, is the boundary of a mountain-walled plain extending into the terminator. High power will reveal many breaks in its hexagonal walls surrounding a floor marred by many smaller craters and fine fissures. This is Jannsen. Look for three prominent interior craters, as well as an ancient rima falling near the shadow’s edge. It may not seem exciting, but remember Jannsen could go back to the time when the Moon first formed – more than four billion years ago!

Even under bright skies, we can still study open clusters – right? Well, not really. Have you noticed how few there are in the spring sky? In fact, the ones that can be seen are rapidly dropping off the edge of the world to the west. (Oops, there goes another one!) They are associated with the winter Milky Way. That’s why open clusters have another name – “galactic clusters!”

Instead, let’s have a look at another interesting subset of things visible in the night sky – galaxies located near bright stars. For instance, Phecda is the southeastern star in the bowl of the Big Dipper, but look again. If you center on Phecda and shift it slightly northwest, you will turn up 9.8 magnitude M109, which is over 55 million light-years further away than its “companion” star.

Tonight Jupiter, with its four bright moons and striking cloudtop features, comes into its own as it reaches opposition. Be prepared for whatever sky conditions permit you to see among the many fine features associated with this mirthful member of our solar family!

Thursday, May 4 – Tonight we’ll continue our lunar explorations as we look for the “three ring circus” of easily identified craters – Theophilus, Cyrillus, and Catherina. Are you ready to discover a very conspicuous lunar feature that was never officially named? Cutting its way across Mare Nectaris from Theophilus to shallow crater Beaumont in the south, you’ll see a long, thin, bright line. What you are looking at is an example of a lunar dorsum – nothing more than a wrinkle or low ridge. Chances are good that this ridge is just a “wave” in the lava flow that congealed when Mare Nectaris formed. This particular dorsa is quite striking tonight because of low illumination angle. Has it been named? Yes. It is unofficially known as “Dorsum Beaumont,” but by whatever name it is called, it remains a distinct feature you’ll continue to enjoy!

It’s still a bit early to begin viewing Jupiter, so let’s look at a double star while we wait for it to gain sky position. Named in honor of King Charles II of England by Astronomer Royal Edmund Halley in 1725, Cor Caroli “the Heart of Charles” (Alpha Canes Venatici) is a splendid example of a bright easily resolved “double of color.” At magnitude 2.9, Cor Caroli is best found by moving a little more than a fist width southwest of Eta Ursa Majoris (Alkaid.) Although the pair is not resolvable in low power binoculars, just about any telescope will distinguish between the pale yellow primary and nicely “spaced” blue secondary.

Tonight Jupiter appears some 44.6 arc seconds in diameter – almost twice as large as the planet Mars ever appears from Earth. At its current apparent size, it only takes 40x magnification to make the planet’s disk appear the size of the Moon unaided. This magnification will reveal the three main cloudtop features in the planet’s atmosphere. Look for the darkly textured northern and southern equatorial belts (NEB & SEB) separated by the bright equatorial zone (EZ). These belts and zone were first seen as early as 1664 and several astronomers including Niccolo Zucchi, Gian Dominico Cassini, Robert Hooke, and Gilles-François Gottigniez are credited with their discovery. This same magnification easily distinguishes the four bright satellites as well. These moons were first reported by Galileo Galilei after a week of observing beginning January 7, 1610.

Friday, May 5 – On this date in 1961, Alan Shepard became the first American in “space.” It was only a 15 minute suborbital ride aboard Mercury craft Freedom 7… But what a ride!

For moon watchers tonight, we celebrate 36 years of space exploration as the Apollo 11 landing site now becomes visible. For telescopes and binoculars the landing area will be found near the terminator along the southern edge of Mare Tranquillitatis. For those who would like a real challenge, try spotting small craters Armstrong, Aldrin, and Collins just east of easy craters Sabine and Ritter. No scope? No problem. Find the dark round area on the lunar northeastern limb – Mare Crisium. Then locate the dark area below that – Mare Fecundatatis. Now look mid-way along the terminator for the dark area that is Mare Tranquillitatis. The bright point west where it joins Mare Nectaris further south is the target for the first men on the Moon.

We were there…

Still up for adventure? What about an observation that happened more than 240 years ago? Like Charles Messier, Johan Hevelius (1611 – 1687) kept a log of things seen while sweeping the night sky using a small telescope. The third object on Hevelius list of 16 “Nebulosae” (designated Hev 1496) came to the attention of Charles Messier who – based on Hevelius’ description – swept the same part of the sky in an attempt to locate it. Failing to discover anything nebulous in the region, Messier added the one and only double star to his famed list as M40.

Start at Mizar and Alcore, and hop about a finger-width northwest. Look for a pair of 9th magnitude stars separated by 49 arc seconds with the fainter 9.3 magnitude component oriented east-northeast. Try turning high power binoculars toward this pair – it’s just possible you may re-discover Hevelius’ “Nebulosa!”

Saturday, May 6 – Tonight is a wonderful chance for binoculars and small scopes to study the Moon. Craters Aristotle and Eudoxus to the north are easily apparent, along with the Caucasus and Apennine mountain range. Looking for a spectacular lunar feature? Look no further than the Valles Alpes. Known also as the “Alpine Valley,” this deep slash across the northern surface is easily visible and lighting conditions will be just right to explore its 1.5 to 21 kilometer wide, and 177 kilometer long expanse.

Even with bright moonlit skies, we still have the opportunity to study doubles – so let’s head towards Corvus and see if we can collect enough starlight to resolve Delta Corvi. Look for a distant and relatively faint companion!

Sunday, May 7 – Tonight, we’ll have a look at crater Eratosthenes. Just slightly north of lunar center and on the terminator, this easily spotted feature dangles at the end of the Apennine Mountain range like a yo-yo caught on a string. Its rugged walls and central peaks make for excellent viewing. If you look closely at the mountains northeast of Eratosthenes, you will see the high peak of Mons Wolff. Named for the Dutch philosopher and mathematician, this outstanding feature reaches 35 kilometers in height. To the southwest of Eratosthenes you may also spot the ruined remains of crater Stadius. Very little is left of its walls and the floor is dotted with small strikes. Near the twin pair of punctuations to its south lie the remains of Surveyor 2!

Two nights ago, Jupiter came as close as it’s going to get to Earth. Now let’s have a “deeper” look at this giant planet. There’s much more to be seen at high power and through stable skies. Wait until Jupiter gains some altitude, then magnify to catch more of those whirling “bands on the run!”

At mid-magnifications the two equatorial belts (NEB and SEB) can be seen flanked by two lesser belts – the North Temperate Belt (NTB) and the South Temperate Belt (STB). These thin and sometimes almost undetectable belts are found at latitudes that move more slowly around the planet’s girth than its equator. Like the NEB and SEB, they come about as a combination of conditions – winds, temperature, and chemical composition. They gang up to darken the albedo (reflectivity) of different parts of Jupiter’s atmosphere under the influence of all the energy unleashed by Jupiter’s less than ten hour rotation.

While observing Jupiter’s features, keep in mind that you are looking through various depths into its atmosphere. In general, things of a blue tint are deeper than things brown. The reds are highest – just above the whites. Unlike our Earth, most of the energy driving “weather” on Jupiter comes from Jupiter itself – since it emits more heat energy than it receives from the Sun. Of course, there is that “whirling dervish” of a rotational speed – some 45,000 kilometers per hour!

May all your journeys be at light speed… ~Tammy Plotner with Jeff Barbour.

M3 – Credit: S. Kalfa and K. Honeycutt/Indiana University/WIYN/NAOA/NSF

Greetings fellow SkyWatchers! If you haven’t had a chance to observe Comet 73/P Schwassmann-Wachmann yet, right now is a good time as it sweeps through Coma Berenices. This week hosts galaxy studies and meteor showers, so enjoy darker skies – because…

Here’s what’s up!

Monday, April 24 – Before dawn, Venus and the Moon have a very close encounter. Today in 1970, China launched its first satellite – the beginnings of a national space program that later saw its first “taikonaut” in space.

Tonight, let’s use our binoculars and telescopes and take a break from galaxy quest. An alternative is to find one of the best northern hemisphere globular clusters – M3. You can locate M3 easily by identifying Cor Caroli (Alpha Canes Venatici) and Arcturus. Sweep your binoculars along a line halfway between the two and you will uncover this condensed beauty just east of Beta Comae. With added inches and magnification, the stars are out to play!

Discovered by Charles Messier on May 3, 1764, this condensed ball of approximately a half million stars is one of the oldest formations in our galaxy. At 35-40,000 light years distant, this awesome globular cluster spans 220 light years and is believed to be 10 billion years old.

Tuesday, April 25 – Today marks the 15th anniversary of the deployment of the Hubble Space Telescope (HST). While everyone in the astronomical community is aware of what this magnificent telescope “sees,” did you know that you can see it with just your eyes? The HST as a satellite can be tracked and observed. Visit the website Heavens-Above and enter your location. This will provide you with a list of times for visible satellite passes from your locale. Although you can’t see a detailed view of the satellite itself from Earth, it’s great fun to use binoculars and watch the Sun glint off all those highly polished surfaces!

Keep a watch on the skies tonight as the Mu Virginid meteor shower reaches its peak of 7 to 10 visible trails per hour. With the dark skies this evening, you might catch one of these medium speed meteors radiating from a point near the constellation of Libra.

Tonight is another “Missed Messier” – 8.9 magnitude NGC 3521. Often ignored by observers because of its isolated location in southern Leo, this tilted galaxy is a “must see” and fine representative of the grand spiral tradition. A delight even in small instruments, the galaxy reveals definite spiral structure in larger scopes and has been compared to M63 in overall structure.

To locate NGC 3521, start at Sigma Leonis and head almost three degrees south to 10.3 magnitude NGC 3640. Power up for a view of this oval-shaped elliptical beauty – then resume your quest for NGC 3521 by heading south-southwest another 1.5 degrees to 75 Leonis. Continue a little more than a finger-width south-southwest to 69 Leonis. NGC 3521 is located a finger-width due west of 69 Leonis.

Now that’s “star hopping’!

Wednesday, April 26 – If you’re up before dawn this morning, be sure to look for Mercury just slightly south of the Moon! On this date in 1920, the Shaply-Curtis debate raged in Washington DC on the nature and distance of spiral nebulae. Shaply contended that all such were part of one huge galaxy – the Milky Way, while Curtis maintained that they were distant galaxies all their own.

Thirteen years later on the same date, Arno Penzias was born. Penzias went on to become a Nobel Prize winner for his part in the discovery of cosmic microwave background radiation (CMBR) through the use of a simple horn-shaped antenna. Their discovery helped further our understanding of cosmology in ways that Shaply and Curtis could have never dreamed!

By 1850, Lord Rosse had used the 72 inch speculum-mirrored “Leviathon at Parsontown” (Birr Castle, Ireland) to catalogue fourteen previously indecipherable glowing clouds in deep space as “spiral nebulae.” The very first one resolved was originally a discovery of Charles Messier – found while chasing a comet on the night of October 13, 1773. That discovery, M51, had to wait 72 years until large reflecting telescopes unveiled its spiral form. It would take another 75 years before M51’s extragalactic nature became an indisputable fact!

Interestingly, observers have now become so accustomed to seeing spiral structure in brighter galaxies that even mid-sized scopes can see M51 – the Whirlpool Galaxy – as a “Grand Spiral.” Tonight see what Rosse saw for yourself.

Start in Ursa Major by locating Mizar (Zeta) and Alkaid (Eta), then rotate the line between these two 90 degrees south using Eta as the pivot. With the line oriented to the southwest, cut it in half. With good conditions and a mid-sized scope, you can be initiated into the mystery of the spiral nebulae – nebulae whose individual stars had to await the development of very large professional scopes and long-exposure photography to reveal their stellar nature to the questing human imagination!

Thursday, April 27 -Tonight is New Moon and a great time to “go deep!”

Start with M87 and fade a degree west for the and neighboring M86. These two massive galaxies can be revealed with almost any optical aid. They appear as a matched set of isolated ellipticals – but on an exceptional night, even small scopes will show much more to this region. The western member of the pair ? the M84 – appears slightly brighter and visibly smaller than the M86 yet the nucleus of M86 is broader, and less intensely brilliant. In large scopes, these two galaxies “leap” out of the eyepiece even at modest magnifications yet reveal no additional structure.

The most fascinating characteristic of the area becomes apparent when looking around M84 and M86. Within the same low power field, no less than five additional galaxies may be made out in a 6″ scope. Forming an easy triangle with the two Messiers, lies southern NGC 4388. At magnitude 11, this edge-on spiral shows a dim star-like core, and reveals classic edge-on structure at double the aperture. In the midst of the triangle formed by the two Messiers and NGC 4388, is 12th magnitude NGC 4387. This dim galaxy will only display a faintly stellar nucleus at mid-aperture, while larger scopes will see a very small face-on spiral with a bright nucleus. Just north of M86 is even dimmer NGC 4402. Like NGC 4388, NGC 4402 demands higher magnifications for positive identification through modest aperture scopes, and at large power you may notice a dust lane with the central core as a curved “bar” of light.

We’ve now gone as “deep” as we can. East of M86 are two brighter NGC galaxies – 4435 and 4438. Through a 6″ scope, NGC 4435 is easily picked out at low power with its simple star-like core and wispy round mantle. NGC 4438 is dim, but even with large aperture elliptical galaxies tend to be rather uninteresting creatures. The beauty of? NGC 4435 and? 4438 are simply their proximity to each other. NGC 4435 shows true elliptical structure, evenly illuminated and visibly faded toward the edges. But, 4438 is quite a different story! This elliptical is much more elongated. A highly conspicuous wisp of galactic material can be seen stretching back toward the brighter, nearby galaxy pair M84/86.

Friday, April 28 – Today was a busy day in astronomical history. Isaac Newton published his Principia in 1686. Newton was an obscure mathematician and early physicist who developed a new form of mathematics to describe planetary motion. In 1774, Francis Baily was born. Baily went on to revise star catalogs and explain the phenomenon now known as “Baily’s Beads” – seen at the start and end of a total solar eclipse. 1900 saw the birth of Jan Hendrick Oort, who quantified the Milky Way’s rotation and envisioned a vast, spherical area of comets outside the solar system now called the Oort Cloud. Today (in 1906) was also the birth date of Bart Jan Bok who studied the structure and dynamics of the Milky Way galaxy and like Oort had a class of objects – Bok Globules – named after him.

And the Milky Way is nowhere to be found! This is the reason we can see so many galaxies during the spring season. The great realm of galaxies we call the “Coma-Virgo Galaxy Cluster” has more in common with our own galaxy than simply not being hidden by the vast array of stars, gas, and dust. Our galaxy and its neighbors (making up the “Local Group”) are inexorably being drawn toward this massive assemblage of island universes based on forces first described by Isaac Newton. Yes, we are slipping. Slipping into a vast gravity well whose center is the giant elliptical galaxy M87!

For skywatchers, no equipment is necessary to enjoy the Alpha Bootid meteor shower tonight. Pull up a comfortable seat and face toward orange Arcturus climbing skyward in the east. These slow meteors have a fall rate of 6 to 10 per hour and leave very fine trails, making an evening of quiet contemplation most enjoyable.

Saturday, April 29 -Tonight see if you can spot the tender beginnings of the Moon after sunset. Observers take pleasure in sweeping the sky with small scopes and binoculars in hopes of finding the thinnest possible lunar crescent. This technique is also employed to turn up “the inferior planets” – Venus and Mercury. But both planets rise just before the Sun! If you rise early, look for them both about an hour before dawn.

Tonight let’s take advantage of dark sky and track down one of the most distant observable studies in the Universe that can be seen in amateur equipment – 2 billion light year distant quasar 3C273. You will need aperture – at least 8″ – and a star chart showing the detailed field in which the quasar is located. This study is so distant that we can only see its super-luminous radiant core looking precisely like a faint 13th magnitude blue star!

Start by re-locating M61 and drop 2.5 degrees southeast for the approximate location of a quasar 3c273 – the incredibly luminous core of a brilliant galaxy possessed of a super-supermassive black hole of more than 500 million solar masses. A galaxy whose brilliance is such that it would almost outshine our own Sun were it placed 33 light years (1 parsec) away and outshine all the light of the Milky Way galaxy 100 times over!

To verify 3C273, you will need a detailed star chart. But knowing you’re looking at one of the most distant objects an amateur can see makes it worth the hunt!

Sunday, April 30 – Karl Frederich Gauss was born on this day in 1777. Known as the “Prince of Mathematics,” Gauss contributed to the field of astronomy in many ways – from computing asteroid orbits to inventing the heliotrope. Out of Gauss’ many endeavors, he is most recognized for his work in magnetism. We understand the term “gauss” as a magnetic unit – a refrigerator magnet carries about 100 gauss while an average sunspot might go up to a 4000. On the most extreme ends of the magnetic scale, the Earth produces about 0.5 gauss at its poles, while a magnetar can produce as much as 10 to the 15th power in gauss units!

While we cannot directly observe a magnetar, those living in the Southern Hemisphere can view a region of the sky where magnetars are known to exist – the Large Magellanic Cloud. Located in the constellation of Dorado, this unaided eye gem is visible even during full moonlight. It’s stuffed with wonderful features such as the Tarantula Nebula – the largest diffuse nebula known in the Universe. It also holds many star clusters, so get out those telescopes and binoculars and explore for your friends in the northern hemisphere!

May all your journeys be at light speed… ~Tammy Plotner with Jeff Barbour.

M102: “The Spindle Galaxy”. Image credit: NOAO/AURA/NSF . Click to enlarge.
Greetings, fellow SkyWatchers! This week begins with a meteor shower, but quickly turns galaxy hunt as we sail the galactic realm of the Virgo Cluster. If all you ask is a tall ship and a star to steer it by – then weigh anchor, because…

Here’s what’s up!

Tuesday, April 18 – Tonight let’s have a look at the Leo Trio – a superb group of two Messier galaxies and NGC 3628. Located some 35 million light years away, they make up their own smaller collection – the M66 galaxy group. All three may be framed together at low power and can best be located by first centering on Theta Leonis and sweeping a little more than a finger-width south to 73 Leonis. By putting star 73 less than a degree west, you will first see 9.5 magnitude M65 enter the low power field. M65 will soon be followed by brighter, larger and more face-on 9.0 magnitude M65. Both were discovered by Charles Messier on March 1, 1780. Larger and fainter yet is the irregular galaxy NGC 3628, which can be included in the low power field by shifting the pair south. Despite having a similar apparent magnitude, one look at this low surface brightness galaxy and you will easily forgive the famed comet hunter and his hard-working friend for missing it!

Want a challenge? Center your scope on 73 Leonis again and shift slightly more than half a degree southwest. Look for mid-sized 11th magnitude NGC 3593. Something even more difficult? How about 12th magnitude galaxy NGC 3596. This face-on spiral galaxy is also of low surface brightness and requires a large scope. Start at bright Chertan and shift less than a degree south-southeast to locate it.

Wednesday, April 19 – Tonight is an ideal time to study “Bode’s Galaxies” – now high in the northwest of the constellation of Ursa Major. To find this extraordinary pair of small scope studies, first locate Phecda (Beta) and 2 Dubhe (Alpha). Draw a line between this bright pair and extend that line an equal distance northwest beyond Alpha. Both galaxies are visible in large finderscopes or binoculars – but if you overextend, look for faint 24 Ursa Majoris and drop a finger-width southeast.

Discovered in December 1774 by J.E. Bode, these two deep sky favorites hold secrets between themselves. Photographed as early as March, 1899, the pair is central to a group of galaxies encompassing the northern circumpolar constellations Ursa Major and Camelopardalis. In small scopes and low powers, the two galaxies give the appearance of “Cat’s eyes” glowing in the night. Mid-sized scopes reveal the spiral nature of the brighter more southerly M81, while mottling can be seen in the irregular spindle shaped M82.

Center on M81 and make a shift of less than a degree southeast. This reveals two 8th magnitude stars forming a right triangle with 10th magnitude face-on spiral galaxy NGC 3077. More difficult is larger and fainter NGC 2976 – a tough find for even mid-aperture due to its low surface brightness and lack of a bright core. To locate the NGC 2976, return to M81 and shift the grand spiral slightly west about a degree and a half.

All four galaxies are part of the M81 group – a small galaxy cluster located some 12 million light years away. M81 and M82 are bound together in a powerful gravitational embrace. Only a few million years ago the two had a close encounter of a most difficult kind – one that largely devastated the structure of the less massive M82 but left its heavier companion completely intact with unrivaled spiral structure of great symmetry and beauty.

Thursday, April 20 – Are you ready to explore further? Then hold on to your star charts and get ready to be lost… The Coma Berenices galaxy group now enters the scene and there are so many galaxies visible that the hard part is being sure of what you are looking at! To get your bearings, start at Denebola (Beta Leonis) and move due east 6.5 degrees to the star 6 Coma Berenices. Once centered on 6 Comae, shift back toward Denebola a half degree to view one of the faintest of the Messier galaxies – M98 – a large near edge-on spiral. Discovered along with M99 and 100 by Pierre M?chain on March 15, 1781, the three discoveries became Messier’s last entries in the original published 3rd edition of his catalog. Although the view of 10th magnitude M98 may be disappointing through smaller scopes, this galaxy comes into its own using larger instruments where its nicely defined and expansive edge-on appearance becomes obvious.

By re-centering 6 Comae in the field and shifting less than one degree southeast, our next study – 9.8 magnitude spiral galaxy M99 – can be reliably identified. Should you go the same distance due east instead, you will encounter 11.5 magnitude NGC 4262. While due south this same distance you will find 11.2 magnitude NGC 4212 and its 13th magnitude neighbor – IC 3061. Although scopes can reveal M99 is a spiral today, it was Lord Rosse (in the spring of 1846) who first recognized the spiral nature of some galaxies.

M100, last on the originally published list, is found by again centering on 6 Comae. At low power, move 2 degrees northeast along a line of finder scope stars. M100 – at magnitude 9.4 – appears no brighter on the surface than M99 due to its greater apparent size. Like M99, M100 was included in Lord Rosse’s original 1850’s list of 14 spiral nebulae. Although face-on in presentation, M100 has two widely displaced and asymmetric spiral arms that can be detected visually through large scopes. Observers using mid-sized scopes should also look for 11.8 magnitude NGC 4312 south of M100. It’s also possible to see 13th magnitude IC 783 roughly that same distance due west.

Friday, April 21 – With dark sky to spare, tonight we continue our explorations of the Coma Berenices galaxy group – part of the larger Virgo supercluster of galaxies lying perpendicular to the plane of our own Milky Way galaxy.

Begin by first centering 6 Comae in the finder, then shift north-northeast 3 degrees to the disparate double, 11 Comae. Shift a little more than a degree due east to one of the brighter Messier galaxies in the Virgo cluster – 9th magnitude M85. In photographs, M85 looks like a giant elliptical galaxy but it’s a lenticular spiral completely devoid of arm structure. Located some 60 million light years away, this luminous mass of stars is relatively free of dust and has a diameter of 125,000 light years. M85 is larger than our own Milky Way, and more densely packed with stars.

A breath west of M85 is tiny 11th magnitude NGC 4394 – an easy study in moderately sized scopes. Slightly more than a degree in the opposite direction is larger 11th magnitude NGC 4293 – another round galaxy but one having a brighter core.

Before you call it a night, take a look east. Brilliant Jupiter is now taking up a year-long residence in Libra. You’ll need to wait for the planet to rise higher in the later evening to get a good view.

Saturday, April 22 – Today celebrates the birthday of Sir Harold Jeffreys. Born in 1891, Jeffreys was an early astrogeophysicist and the first person to envision an Earth with a fluid core in its center. Jeffreys also helped improve our understanding of tidal friction, overall planetary structure, and the origins of the solar system.

Up before dawn? Then enjoy the peak of the Lyrid meteor shower! Since the radiant originates near Vega, improve your odds of spotting them when the constellation Lyra is as high as possible. The Lyrid stream comes from parent comet Thatcher and produces about 15 bright, long-lasting meteors per hour.

Plan tonight to head into the Coma-Virgo galaxy cluster for more challenges. This time we’ll approach from Vindemiatrix (Epsilon Virginis) and move west-northwest along a chain of bright galaxies in the direction of distant Denebola. We’ll start with “Messier-quality” NGC 4762 followed by the M60, M59 and M58. Ready to starhop?

Our first stop lies a little more than a finger width west-northwest of Vindemiatrix: NGC 4762 is a 10.2 magnitude edge-on galaxy with a nearby 10.6 magnitude neighbor, NGC 4762. Most scopes show reveal a faint, thick lens-shaped patch of light oriented north-south. Like dozens of other bright NGC studies, NGC 4762 could have been discovered by Messier and friends in the eighteenth century – but wasn’t!

Continuing west-northwest another finger width reveals M60 – one of the brightest (magnitude 8.8) Coma-Virgo cluster members. This mid-sized elliptical galaxy condenses toward a bright core and shares the field with a pair of nearby companions (11.4 magnitude NGC 4647 and 11.3 magnitude NGC 4638). A touch west-northwest of the M60 group is a fainter (9.8) flattened elliptical galaxy M59. A bit further west is 10.9 magnitude galaxy NGC 4606 – a faint spindle of luminosity. All five of these galaxies can fit into a single low power field of view and will appear roughly as a line of nebulous islands hopping east to west!

Returning slightly east to center again on M59, we shift the scope a degree slightly north and further west to 9.8 magnitude M58. This small, face-on barred spiral is an original discovery of Messier – who found it along with M59 and 60 – while following a comet in the spring of 1779. Unknown to Messier was that the galaxies designated M59 and M60 in his log had already been discovered 4 days earlier (on April 11) by Johann Gottfried Koehler while pursuing the same comet!

Sunday, April 23 – Up early? Then be aware that the Moon occults Uranus. Check IOTA for details! Pioneering quantum physicist Max Planck was born this day in 1858. In 1900, Plank developed the equation explaining the distribution of light emitted by a theoretical “blackbody.” (Planck’s equation describes the relationship between the temperature of a body that absorbs all radiation falling on it – regardless of wavelength – and the wavelength of light radiated from that same body.) Interestingly, almost all the light seen in the heavens originates as “blackbody radiation” from the surface gases of stars. And where does the “absorbed light” come from? Nuclear fusion and the type of light that is far too vibrant for the human eye to see…

In honor of this principle, let’s turn our telescopes on the combined light of trillions of stars as we continue our exploration of the Coma-Virgo realm of galaxies leading up to the light of M87!

To begin tonight’s galaxy hop, start at Nu and extend a line to equal magnitude Omicron Virginis. Continuing the distance between Nu and Omicron places NGC 4429 at the northeast edge of a low power field. Fainter NGC 4371 may be seen less than a degree away northwest of NGC 4429. At magnitude 10.2, NGC 4429 appears about as luminous as previously studied M98. This near edge-on galaxy shows wispy spiral extensions and a bright star-like core.

Now move 1.5 degrees north for bright (magnitude 8.6) giant elliptical galaxy M87 – capital of the Coma-Virgo galaxy cluster. Look also for its 11.2 magnitude companion NGC 4478. Long exposure photographs of M87 reveal this 120,000 light year diameter radiant globe of luminosity is an “all stars” phenomenon. No matter what direction you might observe this giant from, you’d get almost precisely the same view – it’s similar to a massive globular cluster! M87 has collected tens of thousands of globular clusters, numerous smaller galaxies, and converted almost all of its matter to stars – a galaxy with a total mass exceeding several trillion suns.

Once you’ve located M87 it’s time to turn east-southeast (towards Vindemiatrix) for M58, M59, and M60. West-northwest is the direction of the “twin lenticular galaxies” – M84 and 86 – with their own galactic “field of dreams” – a place where large scopes can frame as many as a dozen galaxies in a single one degree field. Just a finger-width north of M87, you can find 9.5 magnitude tilted spiral M88 – looking like a “distant cousin” to the Great Galaxy in Andromeda seen from 60,000 million light years away. Had enough? No? Then head less than a degree west of M88 to find 10.2 magnitude barred spiral M91 in the same low power field. Less than a finger-width south-southeast of M91 is 9.5 magnitude M90 – another tilted spiral and one of eight galaxies (beginning with M84) found and later added to Messier’s list on the same productive night of March 18, 1781 (which also included the M92 globular cluster in Hercules.) How’s that for a night out under the stars?

May all your journeys be at light speed… ~Tammy Plotnerwith Jeff Barbour.

Class I Flamsteed. Image credit: Ricardo Borba. Click to enlarge.
Greetings, fellow SkyWatchers! This week will be filled with meteor showers and moon shine – bright nebula and galaxies. The “Ring King” Saturn is now at its best, so get out under the stars, because…

Here’s what’s up!

Monday, April 10 – Be sure to get up before dawn to enjoy the Virginid meteor shower. The radiant point will be near Gamma in the bowl of Virgo. The fall rate of 20 per hour is above average for meteor showers, and with the Moon out of the equation this morning, you’re in for a treat!

Tonight we’ll start by identifying the large mare just south of central on the lunar disc called Oceanus Procellarum. Look almost centrally within its grey expanse for a large crater which has mostly melted down. This “ghost crater” has no name, but look along its edge for Class I Flamsteed. It is very near here that Surveyor 1 still stands. It made its landing on June 2, 1966 and sent back more than 11,000 pictures of the rock strewn, desert-like floor. This area was one of the first chosen for an Apollo mission landing, but was later scratched for a more central location.

Now let’s move on to 3.2 magnitude Mebsuta – Epsilon Geminorum. Mebsuta is the brightest star (other than Castor) in northwestern Gemini. It has a very distant 9th magnitude companion. As you observe Epsilon, keep in mind its spectral class (G8) is very similar to our Sun. Despite this, Mebsuta glows with an intensity of light 7600 times brighter. It’s one of a rare class of stars called “yellow supergiants” – stars whose nuclear cores are vastly swollen due to advanced age and which have taken on “planetary” proportions. Why planetary? Because the planet Venus would find itself orbiting inside Mebsuta’s 4600 degree C temperature photosphere!

Tuesday, April 11 – Today is the birthday of William Wallace Campbell. Born in 1862, Campbell went on to become the leader of stellar motion and radial velocity studies. He was the director of Lick Observatory from 1901 to 1930, and also served as president of the University of California and the National Academy of Sciences. Also born on this day – but in 1901 – was Donald H. Menzel – assistant astronomer at Lick Observatory. Menzel became Director of Harvard Observatory, an expert on the Sun’s coronosphere and held a genuine belief in the extraterrestrial nature of UFOs. Today in 1960, the first radio search for extraterrestrial civilizations was started by Frank Drake (Project Ozma). In 1986, Halley’s Comet closed within 65 million kilometers of the Earth ? as close as it would get.

If you would like to try out a pair of less obvious lunar features, start out again tonight at Oceanus Procellarum – a vast, grey “sea” encompassing most of the northwestern portion of the Moon. On the terminator to its southwest (and almost due west geographically), you will see two craters nearly identical in size and depth. The southern crater is Billy – one of the darkest floored areas on the Moon. Inside Billy’s bright rim, you will notice an interior as featureless as a mare. North of Billy is Hansteen, whose interior is much brighter and shows complex details. Comparing the two will show Billy was once filled with smooth lava, while Hansteen avoided that fate and shows its native scarred interior.

Although skies will be bright this evening, we can still have a look at brilliant Arcturus – a star whose distance from the Earth (10 parsecs) and radial velocity (less than 200 meters per second) can almost be considered a benchmark. By skydark you will see 0.2 magnitude Arcturus – the brightest star in Bootes and 4th brightest star in the night sky – some 30 degrees above the eastern horizon. Apparent to the eye is Arcturus’ orange color. Because a star’s intrinsic luminosity relates to its apparent brightness and distance, Arcturus’ absolute magnitude is almost precisely the same as its apparent magnitude. Just because Arcturus’ radial velocity is nearly zero doesn’t mean it isn’t on the move relative to our Sun. Arcturus star is now almost as close as it will ever get and its large proper motion – perpendicular to our line of sight – exceeds 125 kilometers per second. Every 100 years Arcturus moves almost 1 degree across the sky!

Wednesday, April 12 – Today in 1961, Yuri Gagarin made one full orbit of the Earth aboard Vostok 1, while also becoming the first human in space. Also today (in 1981) Columbia became the first Space Shuttle to launch.

Tonight let’s launch our lunar explorations as we head for the far north for an “on the edge” feature – Pythagoras. Named for the Greek philosopher and mathematician, you will see this smooth, walled plain as a thin, bright ellipse standing out well against the background of northern Sinus Iridum. Pythagoras is one of the deepest craters in the northern quadrant and would be even more spectacular if visible from overhead – rather than at an angle. Look for its tall and prominent central peak.

Although the Moon will interfere with most studies, we can still check out Iota Cancri – a fine wide disparate double of magnitudes 4.0 and 6.6 separated by some 30 arc seconds. This true binary is so distant from one another that they take over 60,000 years to complete a single orbit around their common center of gravity! Located slightly less than a fist’s width due north of M44, this pair is about 300 light years distant. Both stars shine with a light considerably brighter than our Sun and observers may note a subtle gold and pale blue color contrast between them.

Thursday, April 13 – Tonight’s Full Moon is often referred to as the “Pink Moon” of April. As strange as the name may sound, it actually comes from the herb moss pink- or wild ground phlox. April is the time of blossoming and the “pink” is one of the earliest widespread flowers of the spring season. As you might expect, this Full Moon is also known by other names as well. How about the “Full Sprouting Grass Moon,” the “Egg Moon,” or the coastal tribe based “Full Fish Moon” as we’ve entered the season when fish swim upstream to spawn.

Tonight let’s take a journey towards the 25th brightest star in the night sky – 1.3 magnitude Regulus. Regulus, known as “The Little King,” is the brightest star in Leo. At 77 light-years away, this star is considered a “dwarf” despite shining with a visible light almost 150 times that of Sol. The orange-red giant Arcturus and the blue white “dwarf” Regulus both share a common absolute magnitude very close to 0. The reason the two stars shine with a similar intrinsic brightness – despite widely different physical sizes – is Regulus’ photosphere is more than twice as hot (12,000 C) as Arcturus. While observing Regulus, look for a distant companion of magnitude 8.5. Normally low powers would best concentrate the companion’s light, but try a variety of magnifications to help improve contrast. For those with large aperture scopes, look for a 13.1 magnitude “companion’s companion” a little more than 2 arc seconds away!

Friday, April 14 – Today is the birthday of Christian Huygens. Born in 1629, the Dutch scientist went on to become one of the leaders in his field during the 17th century. Among his achievements were promoting the wave theory of light, patenting the pendulum clock, and improving the optics of telescopes by inventing a new type eyepiece and reducing false color through increasing the focal length of refractor telescopes. Huygens was the first to discover Saturn’s rings and largest satellite – Titan. Of the rings, Huygens said, “Saturn: encircled by a ring, thin and flat, nowhere touching, and inclined to the ecliptic.”

To honor Huygen’s achievements and get a sense just how “on the edge” his observations were at the time, consider the fact Huygens used a home built instrument of 12 foot (336.7) focal length and little more than 2 inches in aperture (57mm). Tonight, why not have a low power look at Saturn using your smallest scope. At what magnification does it become clear to you that the planet has “lost its ears” and gained a ring?

Saturday, April 15 – Tonight keep a watch for the “April Fireballs.” This unusual name has been given to what may be a branch of the complex Virginid stream which began earlier in the week. The absolute radiant of the stream is unclear, but most of its long tails will point back toward southeastern skies. These bright bolides can possibly arrive in a flurry – depending on how much Jupiter’s gravity has perturbed the meteoroid stream. Even if you only see one tonight, keep a watch in the days ahead. The time for “April Fireballs” lasts for two weeks. Just seeing one of these brilliant streaks will put a smile on your face!

While thinking of Jupiter, why not search for the planet’s ghost? The “Ghost of Jupiter” sits after skydark in the constellation Hydra. Start at Alpha Hydrae and head east about a fist’s width to find Lambda within a field of nearby fainter stars. Continue less than a fist southeast and locate Mu. You’ll find the “Ghost of Jupiter” (NGC 3242) lurking in the dark less than a finger-width due south. At magnitude 9, the NGC 3242 gives a strikingly blue-green appearance in even small scopes – despite being more than 1500 light years away.

Before we call it a night, let’s visit with Luna as we look along the southern shore of Mare Humorum and identify ancient crater Vitello. Notice how this delicate ring resembles earlier study Gassendi on the opposite shore.

Sunday, April 16 – With the later rise of the Moon, this is a fine opportunity to have a look at a group of galaxies between Leo’s paws. Start at Regulus and look due east toward Iota Leonis. Halfway between the two (less than a fist from Regulus) and two finger-widths northeast of Rho Leonis, you’ll encounter Messier Galaxies M95 and M96 – both within the same low power field of view. At magnitude 9.2, the brighter – and slightly rounder – M96 lies northeast of 9.7 magnitude M95. Pierre M?chain discovered both galaxies on March 20, 1781 and Messier added them to his catalog 4 days later. These two galaxies are two of the brightest members of the Leo I galaxy group located some 38 million light-years away.

To see another Messier member of the Leo I group, center on M96 and shift the galaxy south. From the north side of the low power field, the 9.3 magnitude galaxy M105, nearby 10th magnitude NGC 3384, and 12th magnitude NGC 3389 will come into view. M105 was discovered by M?chain on the night Messier catalogued M95 and 96 but was not formally added to Messier’s catalog. Based on M?chain’s observing notes, Helen Sawyer Hogg added it to Messier’s list in 1947 – along with galaxy M106 and globular cluster M107. M?chain failed to notice M105’s bright neighboring galaxy – NGC 3384. NGC 3384 is actually slightly brighter than the faintest Messier discovered – M91.

We’re not done yet! If you center on M105 and shift due north less than a degree and a half you will encounter 10th magnitude NGC 3377 – a small elongated galaxy with a stellar core. There are a dozen galaxies visible to moderate amateur instruments (through magnitude 12) in the Leo I region of the sky!

If you are out late enough to study the Moon, relocate previous study Petavius on the southern terminator. Just beyond its east wall, look for a bright ridge that extends from north to south separated by darkness from Petavius. This is Palitzsch, a very strange, gorge-like formation that looks as if it was caused by a meteor plowing through the Moon’s surface. Palitzsch’s true nature wasn’t known until 1954 when Patrick Moore resolved it as a “crater chain” using the 25″ Newall refractor at Cambridge University Observatory.

May all your journeys be at light speed… ~Tammy Plotner with Jeff Barbour.

Download our free “What’s Up 2006” ebook, with entries like this for every day of the year.

Craters Steinheil and Watt. Image credit: Tammy Plotner. Click to enlarge.
Greetings, fellow SkyWatchers! We’ll take a journey to the Moon this week as we explore some outstanding features that make our “neighbor” such a fascinating target. ‘Tis also the season for aurora and we’ll find out why. Be sure to be on watch for meteors and get out the scope to play, because….

Here’s what’s up!

Monday, April 3 – Today marks the 40th anniversary of the launch of the first lunar orbiter – Luna 10. That makes another good reason to view the Moon tonight!

Just a short distance north of the southern cusp, look for a twin pair of craters on the terminator tonight. These are Steinheil and Watt. The two are nearly identical in size an overlap each other. Steinheil, named for mathematician, physicist, optician, and astronomer Karl August von Steinheil is just bit deeper and to the north. Watt, named for my great gandfather James Watt, Scottish engineer and first man to patent the use of a telescope for surveying, will show a wee bit more detail on its floor.

Right now Earth’s magnetosphere and magnetopause are positioned correctly to interact with the Sun’s influencing interplanetary magnetic field (IMF) – and the plasma stream which flows past us as solar winds. During this time after equinox, this phenomenon leaves the door wide open for one of the most awesome signs of spring – aurora! Visit the Geophysical Institute to sign up for aurora alerts and use their tools to help locate the position of the Earth’s auroral oval.

Tuesday, April 4 – Tonight through binoculars or a telescope, let’s head toward the Moon’s southern quadrant and view Theophilus. Located on the terminator and bordered on the northern edge by Mare Nectaris and to the south by Mare Tranquillitatis, Theophilus has an average diameter of 105 km and contains a wonderful multiple-peaked center. This particular crater is unusual because the floor is parabolic. The interior may be dark, but you should see the Sun catching the summit of its huge central peak.

After the Moon sets, keep the watch for the Kappa Serpentid meteor shower. Its radiant lies near the “Northern Crown” – Corona Borealis. The fall rate is low, with an average 4 or 5 per hour.

Tonight will be the last chance for deep sky studies before the Moon dominates, so let’s take advantage. Did you know that there is a galaxy in Cancer? OK – so you did… But, did you know that the galaxy NGC 2775 has been home to 5 supernovae in the last 30 years, or that it’s one of the most unusual but otherwise perfect spiral shapes in the heavens? Then, get a scope out and start by locating Alpha Cancri and head not quite a fist’s width southeast and in line with Zeta Hydrae. NGC 2775 is a 10.3 magnitude oval of luminosity within a low power field.

Wednesday, April 5 – There’s plenty of Moon to explore tonight, so why not try locating an area where many lunar missions left their mark? Binoculars easily reveal the fully disclosed mares of Serenitatis and Tranquillitatis. Set your sites where these two vast lava plains converge. Telescopically you will see a bright “peninsula” where they meet in the west. Look for bright and small crater Pliny to the east of this point.

It is near this rather inconspicuous feature that the remains of Ranger 6 lay forever preserved after “crash-landing” on February 2nd, 1964. Unfortunately, technical errors prevented Ranger 6 from transmitting lunar pictures. Not so Ranger 8! On a very successful mission to the same basic area, NASA received 7137 “postcards from the near side of the Moon” for 23 minutes before a very hard landing. On the “softer side,” Surveyor 5 touched down near this area safely after two days of malfunctions on September 10, 1967. Incredibly, the tiny Surveyor 5 endured temperatures of up to 283 degrees F, but still spectrographically analyzed the area’s soil and also managed to televise over 18,000 frames of “home movies” from its distant lunar location.

Tonight let’s “see double.” At magnitude 2.5, Gamma Leonis – or Algieba – is second brightest member of the Leo “question mark.” Now we have a question for you. Did you know that Algieba is among the most lovely pairs in the night sky? See for yourself! Separated by less than 5 arc seconds, the primary appears ivory, while the secondary is golden. Those with smaller scopes will enjoy the beauty of the “airy disks” displayed by this pair.

Thursday, April 6 – Tonight let’s return to a now familiar lunar feature, Albategnius. A fine challenge for binoculars will be to see if you can make out its bright central peak from the darker lava-covered floor. Power up with a telescope for another challenge. Can you spot the small craters Vogel and Burnham on its southeast edge? Or Ritchey just outside its eastern wall? Look for craters Halley and Hind just between Albategnius and Hipparchus to the north. Hipparchus also holds a very detailed small crater named Horrocks on its northern wall. Shallow crater Saunder is just to its east.

Ready for another challenge? Then let’s head for Iota Leonis – just south of the triangle that makes up eastern Leo. At magnitude 4, it will be difficult to see its close 7th magnitude companion. This is known as a disparate double – a pair unevenly matched in brightness. One of the most difficult double stars in the heavens!

Friday, April 7 – Today in 1991, the Compton Gamma Ray Observatory (GRO) was deployed. Part of NASA’s Great Observatories program, the CGRO was named to honor Dr. Arthur Holly Compton – a Nobel Prize winning physicist. CGRO scanned six decades of electromagnetic radiation at energy ranges well beyond anything the eye can see. Such energies often happen in bursts as extraordinary and cataclysmic events occur in the cosmos.

Be sure to take your telescope out and have a look at the Moon tonight. One of the most sought-after and unusual features will be visible in the southern half of the Moon near the terminator – Rupes Recta! Also known as “The Straight Wall,” this 130 km (75 mile) long, 366 meter (1200 ft) high feature slopes upward with the steepest angle on the lunar surface (41 degrees). It will be a challenge under these lighting conditions, but look for triple ring of craters Ptolemy, Alphonsus, and Arzachel to guide you. The “Straight Wall” appears as a very thin line stretching across the edge of Mare Nubium.

Be on the lookout for bright streaks from the Delta Draconid meteor shower. Its radiant lies near the border with Cepheus to the east. The fall rate is quite low – around 5 meteors per hour.

Even with the Moon, let’s try for a scattered open cluster toward the west in Auriga. At magnitude 5.4, NGC 2281 should be visible as a nebulous mist in binoculars on a dark night, but you’ll need a scope and high power to darken the sky enough to see the bright members found near its core. NGC 2281 is around 1500 light years distant and 50 million years old. It can best be found by extending a line from Capella to Beta Aurigae an equal distance east to a pair of 5th magnitude stars separated by a finger width. NGC 2281 lies less than one degree southeast of the eastern member of this pair (58 Aurigae.)

Saturday, April 8 – Start your evening by revisiting crater Copernicus as it becomes visible to even the most modest of optical aids. Small binoculars will see Copernicus as a bright “ring” about midway along the lunar dividing line of light and dark called the “terminator.” Telescopes will reveal its 97 km (60 mile) expanse and 120 meter (1200 ft.) central peak to perfection. Copernicus holds special appeal as the aftermath of a huge meteoric impact! At 3800 meters deep, its walls are 22 km thick. Over the next few days, the impact ray system extending from this tremendous crater will become wonderfully apparent.

Tonight we’ll use Copernicus as a guide and look north-northwest to survey the Carpathian Mountains. The Carpathians ring the southern edge of Mare Imbrium beginning well east of the terminator. But let’s look on the dark side. Extending some 40 km beyond into the Moon’s own shadow, you can continue to see bright peaks – some reaching 2000 meters high! Tomorrow, when this area is fully revealed, you will see the Carpathians begin to disappear into the lava flow forming them. Continuing onward to Plato – on the northern shore of Mare Imbrium – look for the singular peak of Pico. Between Plato and Mons Pico you will find the many scattered peaks of the Teneriffe Mountains. It is possible that these are the remnants of much taller summits of a once precipitous range. Now the peaks rise less than 2000 meters above the surface. Time to power up! West of the Teneriffes, and very near the terminator, you will see a narrow line of mountains, very similar in size to the Alpine Valley. This is known as the Straight Range and some of its peaks reach as high as 2000 meters. Although this doesn’t sound particularly impressive, that’s over twice as tall as the Vosges Mountains in west central Europe and on average, comparable to the Appalachian Mountains of the eastern United States.

Sunday, April 9 – Tonight let’s continue our lunar mountain climbing expedition and revisit the “big picture” on the lunar surface. Tonight all of Mare Imbrium is bathed in sunlight and we can see its complete shape. Appearing as a featureless ellipse bordered by mountain ranges, let’s identify them all again. Starting at Plato and moving east to south to west you will find the Alps, the Caucasus, the Apennine and the Carpathians mountains. Look at the form closely=85doesn’t it look like it’s possible that an enormous impact created the entire area? Compare it to the younger Sinus Iridium ringed by the Juras Mountains. It may have also been formed by a much later and very similar massive impact event.

In the mood for a double star? Then let’s head west and away from the Moon. Begin your search right after skydark with El Nath – Beta Tauri. From Beta shift about two finger-widths east-northeast to identify very dim 26 Aurigae. At low power, look for an 8th magnitude companion due west of the 5.5 magnitude primary. The brighter star should give a warm yellow appearance while the fainter appears slightly more blue. This pair shares space with a third member (magnitude 11.5) – some three times further out from the primary than the closer, brighter secondary. Thanks to lunacy, small instruments will have difficulty distinguishing the C star in such bright skies.

May all your journeys be at light speed… ~Tammy Plotner. (contributing writer: Jeff Barbour).

Download our free “What’s Up 2006” ebook, with entries like this for every day of the year.

110 Messier Objets. Image credit: Hartmut Frommert – SEDS. Click to enlarge.
Greetings, fellow SkyWatchers! It’s that time of year again … Are you ready to run the Messier Marathon? If you’d rather take your stars at a more leisurely pace – then follow along as we spread 110 of the best sky objects out over the next week. Let’s hope for clear skies as we grab binoculars or telescopes and head out into the night, because…

Here’s what’s up!

Monday, March 27 – This is going to be one incredibly busy week as we start off the show with an occultation of Uranus by the Moon. Check with IOTA for more details.

As we open our week long tour known as a “Messier Marathon,” the late rise of the Moon tonight will be on the side of observers.

Beginning as soon as the sky darkens enough to find the guidestar Delta Cetus, the M77 spiral galaxy will be your first, and the M74 spiral galaxy east of Eta Pisces will be your second mark. Both of these galaxies are telescopic only and will be an extreme challenge at this time of year due to their low position. Even computer-assisted scopes will have some difficulty revealing this pair under less than optimal conditions. Next up is M33 west of Alpha Triangulum. With ideal skies, the “Pinwheel Galaxy” could be seen in binoculars, but skybright will make this huge, low surface brightness spiral difficult for even telescopes at low power. M31 – the Andromeda Galaxy – will, however, be a delightful capture for both binoculars and scopes just west of Nu Andromedae. For the telescope, two more on the list are companions to M31 – the elliptical M32 on the southeastern edge and M110 to the northwest.

Let’s head northwest as we take on two open clusters visible to both telescopes and binoculars. You can find M52 easiest by identifying Alpha and Beta Cassiopeia, drawing a mental line between them and extending it the same distance northwest of Beta. Next just hop north of Delta to pick up our ninth object – the M103 open cluster. Time to head south towards Perseus and go back to the telescope to locate M76, the “Little Dumbbell” planetary nebula, just north of Phi. Binoculars are all that’s needed to see the M34 open cluster also in Perseus, located roughly halfway between the “Demon Star” Algol and lovely double Almach, Gamma Andromeda.

Now that skies are dark and the fastest setting objects are out of the way, we can take a moment to breathe as we view M45 – the Pleiades. The “Seven Sisters” are easily visible to the unaided eye high in the west and their cool, blue beauty is incomparable in binoculars or telescopes. Our next “hop” is with the “rabbit” Lepus as we go back to the south and identify Beta and Epsilon. Triangulating with this pair to the south is a nearly fifth magnitude star (ADS 3954) which will help you locate the small globular M79 to its northeast. At around magnitude 8.5, it is possible to see its very tiny form in binoculars, but M42 – the “Great Orion Nebula” is much easier. The next object, M43, is part of the Orion Nebula, and you will catch it as a small “patch” to the north-northeast. The next two objects, M78 northeast of Zeta Orionis and the M1 Crab Nebula northwest of Zeta Tauri, are both achievable in binoculars with excellent conditions, but are far more interesting to the telescope.

Now we can really relax. Take a few minutes and grab a cup of coffee or hot chocolate and get warmed up. The remaining objects on our observing list for tonight are all very easy, very well positioned for early evening, and all observable in just binoculars. Are you ready? Then let’s go.

M35 is just as simple as finding the “toe” of Gemini – bright Eta. A short hop to the northwest will capture this fine open cluster. The next stop is Auriga and we’ll go directly between silicon star Theta and southern Beta. About halfway between them and slightly to the east you will find open cluster M37. This time let’s use Theta and Iota to its west. Roughly halfway between them and in the center of Auriga you will find M38 and a short hop southeast will capture M36. Now let’s get Sirius and finish this list for tonight. The open cluster M41 in Canis Major is found just as quickly as drifting south of the brightest star in the sky. The last three for tonight couldn’t be any easier – because we just studied them before. Go capture M93, M47 and M46 in Puppis… And give yourself a well-deserved pat on the back.

You’ve just conquered 24 Messiers.

Tuesday, March 28 – Ready for tonight’s challenge? Then nap away the very early evening hours and let’s head out well before bedtime to work on the next section of our week-long “marathon.”

First up will be four binocular targets, the incredibly colorful open cluster M50 is roughly a third of the way in a line drawn between Sirius and Procyon – use binoculars. Hydra is a difficult constellation, but try dropping south-southeast of the most eastern star in Monoceros – Zeta – about half a fist’s width to discover relatively dim open cluster M48. Far brighter, and usually visible to the unaided eye is M44, better known as the Beehive Cluster, just a scant few degrees north-northwest of Delta Cancri. From Delta, go south and identify Alpha because M67 is just to its west. It will appear as a “fine haze” to binoculars, but telescopes will find a spectacular “cloud” of similar magnitude resolvable stars.

Now we really do have to use the telescope again because we’re going “lion taming” by hunting galaxies in Leo. Let’s trade one Alpha for another as we head west to Regulus. Roughly about a fist width east of this major star you will see two dim stars that may require the use of the finderscope – 52 to the north and 53 to the south. We’re heading right between them. About a degree and a half south of 52, you will discover ninth magnitude elliptical M105. Larger scopes will also show two additional faint galaxies, NGC 3384 and NGC 3389 to M105’s west. Continuing about a degree south towards star 53 you will spot the silver-gray beauty of M96 in a relatively starless field. Enjoy its bright nucleus and wispy arms.

About another degree west will bring you to M95, which is neither as bright nor as large as its Messier “neighbor.” Small scopes should show a brightening towards its center and large ones should begin to resolve out the arms of this awesome barred spiral. Our next destination is the southwestern star of the three that mark Leo’s “hips,” Theta Leonis – or more commonly called Chort. South of it you will see faint star 73 and right around one degree to its east-southeast you will locate a pair. In small scopes at low power, M65 and M66 are same field. The western M65 and eastern M66 are both beautiful spirals.

Now let’s head north for another “same field pair” of galaxies and hunt down M81 and M82 in Ursa Major. Many folks have trouble “star hopping” to these galaxies, but a very simple way of finding them is to draw a mental line between Phecda (Gamma) and Dubhe (Alpha). By extending that line beyond Dubhe almost the same distance, you’ll locate our next two “marathon” objects. At low power with a smaller scope, the southern-most and most pronounced of the two is the stunning M81 with its bright core. To the north is broken, spindle-shaped peculiar galaxy M82. Viewable in binoculars, we’ll study more about this pair later on as we head for Mirak (Beta) and our next galaxy. About a degree and a half southeast you will see a 10th magnitude “scratch” of light. This great edge-on galaxy – M108 – should show at least four brighter “patches” to the small scope and a nice dark dust-lane to larger ones. Continuing about another half degree southeast will bring you to the planetary nebula M97. Also known as the “Owl,” this 12th magnitude beauty is roughly the same diameter as Jupiter and can be spotted under optimal conditions with binoculars – but requires a large scope at high power to begin to discern its features. Let’s continue south to Phecda and less than half a degree to the east you will locate M109. In the field with Gamma, M109 will show its faded central bar and prominent nucleus to the small scope, but requires large aperture and high magnification to make out structure. The last in Ursa Major is an error on Messier’s part. Labeled as M40, this object is actually double star WNC 4, located in the same eyepiece field as 70 Ursae Majoris to the northeast.

Now let’s move into Canes Venatici and round up a few more. This is an area of dimmer stars, but the two major stars, Alpha (it is called Cor Caroli and it is a wonderful double star) and Beta are easily recognizable to the east of the last star in the “handle” of the “Big Dipper” (Eta). The northernmost is Beta and you will find the soft-spoken spiral galaxy M106 almost midway between it and Phecda less than 2 degrees south of star 3. M94 is a much brighter, compact galaxy and is found by forming an isosceles triangle with Alpha and Beta Canum with the imaginary apex towards Eta Ursae Majoris. M63 is a very pretty, bright galaxy (often known as “the Sunflower”) that approaches magnitude 10 and is found about one-third the distance between Cor Caroli and Eta Ursae Majoris (Alkaid). Still heading towards Alkaid (Eta UM), the incomparable M51 comes next. Near Eta you will see an unmistakable visual star called 24 CnV, the “Whirlpool” is the same basic distance to the southwest. Now that we’re back into “big bear country” again, we might as well head on to the M101 “Pinwheel” galaxy which is found by following the same trajectory and distance to the other side of Alkaid. Before we head on, let’s continue north and clean up… ummm… another “messy mistake.” The accepted designation for M102 is lenticular galaxy NGC 5866, located in Draco south east of Iota.

Now let’s finish up – it’s getting late. Our next stop will be to identify the three primary stars of Coma Berenices now high in the east above Arcturus. You will find small globular cluster M53 northeast of Alpha. One of the coolest galaxies around is M64 (known as the “Blackeye”) just a degree east-northeast of 35 Comae, which is about one-third the distance between Alpha Comae and Alkaid. The last, and most outstanding for the night, is a globular cluster that can be seen in binoculars – M3. As strange as this may sound, you can find M3 easily by drawing a line between Cor Caroli and Arcturus. Starting at Arcturus, move up about one third the way until you see Beta Comae to the west of your “line”… Poof. There it is.

Awesome job. We’ve just completed another 24 objects and we’ve claimed 48 on the Messier list before bedtime in two days.

Wednesday, March 29 Born today in 1749, Pierre Laplace was the mathematician who invented the metric system and the nebular hypothesis for the origin of the solar system. Also born on this day in 1693 was James Bradley, an excellent astrometrist who discovered the aberration of starlight in 1729, as well as the nutation of the Earth. In 1802, Heinrich W. Olbers discovered the second asteroid, Pallas, in the constellation Virgo while making observations of the position of Ceres, which had only been discovered fifteen months earlier. Five years later on this same date in 1807, Vesta – the brightest asteroid – was discovered by Olbers in Virgo, making it the fourth such object found.

And if you thought this day was busy in history, then it’s about to get a whole lot busier as we add a total solar eclipse! While the path of totality is quite narrow, viewers across portions of Asia, Europe and North Africa will see the Sun partially eclipsed. Please check Fred Espenak’s Eclipse Home Page for precise times and locations… And check the web for live feeds of the event!

We have one more day until New Moon, but the challenge will not be so much avoiding Luna, or the visibility of the next objects – but the “window of opportunity” in which we’ll be able to see them. Am I going to ask you to stay up past your bedtime? Darn right…

These next targets will be best viewed after midnight when the constellations of Coma Berenices and Virgo have well risen, providing us with the darkest sky and best position. For the large telescope, we are going to be walking into an incredibly rich galaxy field that we will touch on only briefly because they will become the object of future studies. Just keep in mind that our Messier objects are by far the brightest of the many you will see in the field. For the smaller scope? Don’t despair. These are quite easy enough for you to see as well and probably far less confusing because there won’t be so many of them visible. Now let’s identify the easternmost star in Leo – Denebola – and head about a fist width due East…

Our first will be M98, just west of star 6 Comae. It will be a nice edge-on spiral galaxy in Coma Berenices. Next return to 6 Comae and go one degree southeast to capture M99, a face-on spiral known as the “Pinwheel” that can be seen in apertures as small as 4″. Return to 6 Comae and head two degrees northeast. You will pass two fifth magnitude stars that point the way to M100 – the largest appearing galaxy in the Coma/Virgo cluster. To the average scope, it will look like a dim globular cluster with a stellar nucleus. Now let’s continue on two degrees north where you will see bright yellow 11 Comae. One degree northeast is all it takes to catch the ninth magnitude, round M85. (Ignore that barred spiral. let’s keep moving…) Now, let’s try a “trick of the trade” to locate two more. Going back to 6 Comae, relocate M99 and turn off your drive. If you are accurately aligned to the equator, you may now take a break for 14 minutes. When you return the elongated form and near stellar nucleus of M88 will have “drifted” into view. Wait another two to three minutes and the faint barred spiral M91 will have joined the show in a one degree field of view? Pretty fun, huh?

Now let’s shift guidestars by locating bright Vindemiatrix (Epsilon Virginis) almost due east of Denebola. Let’s hop four and a half degrees west and a shade north of Epsilon to locate one of the largest elliptical galaxies presently known – M60. At a little brighter than magnitude 9, this galaxy could be spotted with binoculars. In the same telescopic low power field you will also note faint NGC 4647 which only appears to be interacting with M60. Also in the field is our next Messier, bright cored elliptical M59 to the west. (Yes, there’s more – but not tonight.) Moving a degree west of this group will bring you to our “galactic twin,” fainter M58. Moving about a degree north will call up face-on spiral M89, which will show a nice core region in most scopes. One half degree northeast is where you will find the delightful 9.5 magnitude M90 – whose dark dust lanes will show to larger scopes. Continue on one and a half degrees southwest for M87, one of the first radio sources discovered. This particular galaxy has shown evidence of containing a black hole and its elliptical form is surrounded by more than 4,000 globular clusters.

Just slightly more than a degree northwest is a same field pair, M84 and M86. Although large aperture scopes will see many more in the field, concentrate on the two bright cored ellipticals which are almost identical. M84 will drift out of the field first to the west and M86 is east. Next we will select a new guidestar by going to 31 Virginis to identify splendid variable R about a degree to its west. We then move two degrees northwest of R to gather in the evenly lighted oval of M49. Now shifting about three degrees southwest, you will see a handsome yellow double – 17 Virginis. Only one-half degree south is the large face-on spiral, M61. Larger scopes will see arms and dust lanes in this one. Last for tonight is to head for the bright blue beauty of Spica and go just slightly more than a fist width (11 degrees) due west. M104 – the “Sombrero” galaxy – will be your reward for a job well done.

Congratulations. You’ve just seen 17 of the finest galaxies in the Coma/Virgo region and our “Marathon” total for three days has now reached 65. We’re over halfway home…

Thursday, March 30 – Today celebrates the first flyby of Mercury by Mariner 10 in 1974.

Hey… It’s New Moon. While tonight would be the “perfect choice” for completing a Messier Marathon from start to finish, there are no iron-clad guarantees that the sky will cooperate on this date. Even worse? Many of us have to work the next day. So what’s an astronomer to do, eh? How about if we try an “early to bed and early to rise” attitude and conquer these next objects well ahead of the dawn? Set your alarm for 3:00 am, dress warm and let’s dance.

With Corvus relatively high to the south, the drop is about five degrees to the south-south east of Beta Corvi. Just visible to the unaided eye will be the marker star – the double A8612. Eighth magnitude M68 is a bright, compact globular cluster in Hydra that will appear as a “fuzzy star” to binoculars and a treat to the telescope. Our next is tough for far-northern observers, for the “Southern Pinwheel” – M83 – is close to ten degrees southeast of Gamma Hydrae. (This is why it is imperative to get up early enough to catch this constellation at its highest.)

Now we’re going to make a wide move across the sky and head southeast of brilliant Arcturus for Alpha Serpentis. About 8 degrees southwest you will find outstanding globular cluster M5 sharing the field with 5 Serpens. Now locate the “keystone” shape of Hercules and identify Eta in its northwest corner. About one-third of the way between it and Zeta to the south is the fantastic M13, also known as the “Great Hercules Globular Cluster.” A little more difficult to find is the small M92 because there are no stars to guide you. Try this trick – Using the two northernmost stars in the “keystone,” form an equilateral triangle in your mind with its imaginary apex to the north. Point your scope there. At sixth magnitude, this compact globular cluster has a distinct nucleus.

Now we’re off to enjoy summer favorites and future studies. M57, the “Ring Nebula,” is located about halfway between Sheilak and Sulafat. You’ll find the small globular M56 residing conveniently about midpoint between Sulafat and Alberio. About 2 degrees south of Gamma Cygni is the bright open cluster M29. And equally bright M39 lays a little less than a fist width to the northeast of Deneb. If you remember our hop north of Gamma Sagitta, you’ll easily find M27, the “Dumbbell Nebula,” and the loose globular, M71, just southwest of Gamma. All of the objects in this last paragraph are viewable with binoculars (albeit some are quite small) and all are spectacular in the telescope.

And now we’ve made it to 76 on our “Messier Hit List.”

Friday, March 31 – So, are you having fun yet? Now we’re moving into early morning skies and looking at our own galactic halo as we track down some great globular clusters. What time of day, do you ask? Roughly two hours before dawn…

Ophiuchus is a sprawling constellation and its many stars can sometimes be hard to identify. Let’s start first with Beta Scorpii (Graffias) and head about a fist’s width to the northeast. That’s Zeta and the marker you will need to locate M107. About one quarter the way back towards Graffias, you will see a line of three stars in the finder. Aim at the center one and you’ll find this globular in the same field. Now go back to Zeta and you will see a pair of similar magnitude dim stars higher to the northeast. The southernmost is star 30 and you will find the M10 globular cluster about one degree to its west. M12 is only about three degrees further along to the northeast. Both are wonderfully large and bright enough to be seen in binoculars.

Now we need to identify Alpha in Ophiuchus. Head toward Hercules. South of the “keystone” you will see bright Beta Hercules with Alpha Hercules to the southeast. The next bright star along the line is Alpha Ophiuchi and globular cluster M14 is approximately 16 degrees south and pretty much due east of M10. Now let’s head for bright Eta Ophiuchi (Sabik) directly between Scorpius and Sagittarius. The next globular, M9, is about three and a half degrees southeast.

Now let’s move on to an easier one. All you need to know is Antares to find the globular cluster M4 in Scorpius. All you have to do is aim your binoculars there, for this diffuse giant is just a little over one degree to the west. Go back to Antares and shift about four degrees to the northwest and you’ll find compact, bright globular M80. It will be very small in binoculars, but it’s quite bright. Going back to the scope is best for M19, although it’s easy to find around seven degrees due east of Antares. The last for this morning is M62 about a half a fist’s width to the south.

Hey, you’re doing terrific. Some of these are tough to find unless you’ve had practice… But now we’re up to a total of 85.

Saturday, April 1 – Today in 1960, the first weather satellite – Tiros 1 – was launched. Let’s hope our weather holds as we complete our week long Messier Marathon!

Ready to get up early again? I know it’s hard, but what we’re after this morning is truly worth it. These are some of the most beautiful objects in the sky.

The lower curve of Scorpius is quite distinctive and the unaided eye pair you see at the “stinger” is beautiful double Shaula (Lambda) and its slightly less bright neighbor Upsilon. Aim your binoculars there and head towards the northeast and you cannot miss M6, the “Butterfly Cluster.” Below it and slightly east is a hazy patch, aim there and you will find another spectacular open cluster M7, often known as “Ptolemy’s Cluster.”

Now go north and identify Lambda Aquilae and you will find M11, the “Wild Duck” open cluster just to the west. About the same distance away to the south/southwest you will spot M26, another open cluster. These are all great binocular targets, but it will take an exceptionally dark, clear sky to see the Eagle Nebula associated with the M16 easy open cluster about a fist’s width away to the southwest. Far easier to see is the “Nike Swoosh” of M17 just a little further south. Many of you know this as the “Omega” or “Swan” nebula. Keeping moving south and you will see a very small collection of stars known as M18, and a bit more south will bring up a huge cloud of stars called M24. This patch of Milky Way “stuff” will show a wonderful open cluster – NGC 6603 – to average telescopes and some great Barnard darks to larger ones.

Now we’re going to shift to the southeast just a shade and pick up the M25 open cluster and head due west about a fist’s width to capture the next open cluster – M23. From there, we are dropping south again and M21 will be your reward. Head back for your scope and remember your area, because the M20 “Triffid Nebula” is just a shade to the southwest. Small scopes will pick up on the little glowing ball, but anything from about 4″ up can see those dark dust lanes that make this nebula so special. You can go back to the binoculars again, because the M8 “Lagoon Nebula” is south again and very easy to see.

This particular star hop is very fun. If you have children who would like to see some of these riches, point out the primary stars and show them how it looks like a dot-to-dot “tea kettle.” From the kettle’s “spout” pours the “steam” of the Milky Way. If you start there, all you will need to do is follow the “steam” trail up the sky and you can see the majority of these with ease.

Our Messier total has now risen to 98…

Sunday, April 2 – OK, folks… It’s “crunch time” and the first few on this list will be fairly easy before dawn, but you won’t have long before the light steals the last few from the sky.

At the top of the “tea kettle” is Lambda. This is our marker for two easy binocular objects. The small M28 globular cluster is quite easily found just a breath to the north/northwest. The larger, brighter and quite wonderful globular cluster M22 is also very easily found to Lambda’s northeast. Now we’re roaming into “binocular possible” but better with the telescope objects. The southeastern corner of the “tea kettle” is Zeta, and we’re going to hop across the bottom to the west. Starting at Zeta, slide southwest to capture globular cluster M54. Keep heading another three degrees southwest and you will see the fuzzy ball of M70. Just around two degrees more to the west is another globular that looks like M70’s twin. Say good morning to M69.

Now it’s really going to get tough. The small globular M55 is out there in “No Man’s Land” about a fist’s width away east/south east of Zeta and the dawn is coming. It’s going to be even harder to find the equally small globular M75, but if you can see Beta Capricorn it will be about a fist’s width southwest. Look for a “V” pattern of stars in the finder and go to the northeastern star of this trio. You should be able to put it in the same low power field. Without the “square” of Pegasus to guide us, look low to the east and identify Enif by its reddish color. (Delphinus above it should help you.) Power punch globular M15 is to Enif’s northwest and you should be able to see the star on its border in the finderscope. Let’s be thankful that M2 is such a fine, large globular cluster. The hop is two thirds of the way between Enif and Beta Aquarius, or just a little less than a fist’s width due west of Alpha.

Let’s hope that Beta is still shining bright, because we’ll need to head about a fist’s width away again to the southwest to snag what will now be two very dim ones – the M72 globular cluster and M73 open cluster just west of Nu Aquarius. We’re now running just ahead of the light of dawn and the M30 globular cluster is our last object. Hang on Delta Capricornus and show us the way south/southwest to star 41. If you can find that? You’ve got the very last one…

We’ve done the Messier Catalog of all 110 objects in just one week!

Is this a perfect list with perfect instructions? No way. Just like the sky, things aren’t always perfect. This is just a general guideline to helping you find the Messier objects for yourself. Unless you are using a computer-guided scope, it truly takes a lot of practice to find all the Messiers with ease, so don’t be discouraged if they just don’t fall from the sky. You might find all of these in one year or one week – and you just might find all of them in one good night. Regardless of how long it takes you – or when the skies cooperate – the beauty, joy and reward is the peace and pleasure it brings.

Today in 1889, the Harvard Observatory’s 13″ refractor arrived at Mt. Wilson. Just one month later, it began a long astronomical legacy at Lick Observatory. It was here that the largest telescopes in the world resided from 1908 to 1948. The 60″ for the first decade, and followed by the 100″. This latter mirror is still the largest solid piece ever cast in plate glass and weighed 4 1/2 tons. Would you believe it’s just 13 inches thick?

Thankfully we’d didn’t need it for our marathon!

Today in 1845, the first photograph of the Sun was taken. While solar photography and observing is best left to properly filtered telescopes, no special equipment is necessary to see some effects of the Sun – only the correct conditions. We’ll find out why tomorrow night…

Tonight let’s take it easy after our marathon and relax as we take a look at lunar features. Begin by identifying Mare Crisium and shallow crater Cleomides to its north. About twice its width northwest, you will see a sharply well-defined Class I crater Geminus. Named for the Greek astronomer and mathematician Geminos, this 86 kilometer wide crater shows a smooth floor and displays a long, low dune across its middle.

May all your journeys be at light speed… ~Tammy Plotner.

M44: The Beehive. Image credit: NOAO/AURA/NSF. Click to enlarge.
Greetings, fellow SkyWatchers! This week brings darker skies, bright star clusters, meteor showers, unusual nebulae and a chance to participate in G.L.O.B.E. at Night! Whether you use a telescope, binoculars, or just your eyes – you’ll find a wealth of astronomy activities this week. So turn an eye to the sky, because….

Here’s what’s up!

Monday, March 20 – Tonight the obscure constellation of Cancer is now well placed for observation – so why not compare views of the two Messier clusters found there? They’re both binocular and telescope easy!

M44 is one of the most easily recognized studies in the night sky. Like the Pleiades and Hyades in Taurus, Praesepe, “The Manger,” comes to us as a discovery from antiquity. Its myths include one about two neighboring bright stars – Asellus Australis and Asellus Borealis. These two stars are said to be donkeys taking meals from the manger. Known to amateur astronomers as “the Beehive Cluster,” Galileo was the first to discern its stellar nature. Even with his modest scope, he resolved around forty of its brightest members. Modern telescopes have determined that at least 200 of the 350 or more stars visually associated with M44 move together and are a part of the 700 million year old open cluster.

Open cluster M67 is little less than a fist width southeast of M44, or about a finger-width west of visual star – Acubens (Alpha Cancri). Five times further away than M44, and at 3.5 billion years of age, M67 is one of the oldest open clusters in our galaxy. Its brightest stars have already gone “white dwarf” after long ago exhausting their nuclear fuel. You’ll notice it’s quite dense and surprisingly faint for a Messier study. Its discoverer, Johann Gottfried Koehler, was unable to resolve any stars! Today’s telescopes resolve dozens – even hundreds – of cluster members while most binoculars will find it to appear quite “galactic!”

Be on the lookout for Antares as it and the Moon rise together. There will be an occultation tonight, so be sure to check IOTA for times and details in your area.

Tuesday, March 21 – How about one last open cluster before going galaxy hunting? Our study – M48 – is roughly 3 degrees southeast of Zeta Monocerotis. Like M44 in Cancer, M48 lies within the limits of unaided sight. Its brightest member is a spectral type A star, intrinsically some 70 times brighter than our own Sun, but it only appears close to 9th magnitude thanks to 1500 light-years separating us. M48 is quite large, and will show several dozen stars within reach of small scopes and binoculars.

Spring has arrived and with it comes the time of galaxies. To celebrate this new astronomical season, have a look at NGC 2903. Located about a finger-width south-southeast of Lambda Leonis, this 8.9 magnitude tilted spiral looks very much like a slightly fainter version of M81 in Ursa Major. Larger scopes easily catch hints of the galaxy’s spiral extensions and all will show considerable brightening toward the very expansive core region!

Wednesday, March 22 – Born on this day in 1799 was Friedrich Argelander, a compiler of star catalogues. Argelander also studied variable stars and created the first international astronomical organization entitled simply the “Astronomical Society.”

If you’d like to join in an Astronomical Society event, then take the time to visit the Astronomical League webpages and participate in the National Optical Astronomy Observatory (NOAO) call to all observers to participate in G.L.O.B.E. at Night program. No special equipment is needed and your observations “count”!

With a later moonrise tonight, let’s have a look at two meteor showers. We’ll start first with the Camelopardalids. These have no definite peak, and a screaming fall rate of only one per hour. They do have one claim to fame however – these are the slowest meteors known – arriving at a speed of only 7 kilometers per second!

Far more interesting will be to watch for the peak of the March Geminids. These were first discovered and recorded in 1973, then confirmed in 1975. With a much improved fall rate of about 40 per hour, these faster meteors will be fun to follow. When you do see a bright streak, trace it back to its point of origin. Did you see a Camelopardalid? Or a March Geminid?

While out, let’s use the late rise of the Moon to our advantage and head about 2 degrees northeast of star 13 in Monoceros. Our study will be NGC 2261 – more commonly known as “Hubble’s Variable Nebula.” Named for Edwin Hubble, this 10th magnitude object is very blue in appearance through larger apertures, and a true enigma. The fueling star, the variable R Monocerotis, does not display a normal stellar spectrum and may be a proto-planetary system. R is usually lost in the high surface brightness of the “comet-like” structure of the nebula, yet the nebula itself varies with no predictable timetable – perhaps due to dark masses shadowing the star. We do not even know how far away it is, because there is no detectable parallax!

Thursday, March 23 – Today in 1840, the first photograph of the Moon was taken. The daguerreotype plate was exposed by American astronomer and medical doctor, J. W. Draper. Draper’s fascination with chemical responses to light also led him to another first — a photo of the Orion Nebula.

Tonight let’s have a look at a study in light and dark as we view our large binocular and telescope study for this evening. You’ll find it located roughly halfway between Sirius and Alpha Monocerotis – NGC 2359. Known as “Thor’s Helmut,” this bubble-like emission nebula was blown into existence by the superheated blue giant star in its center. NGC 2359 spans about 30 light-years some 15,000 light-years away. The supercharging Wolf-Rayet star produces high speed stellar winds which may have interacted with a nearby molecular cloud giving this strange nebula its curved shape. At magnitude 11, “Thor’s Helmut” is an unusual observation to add to your collection of “head gear.”

Friday, March 24 – Today is the birthday of Walter Baade. Born in 1893, Baade was the first to resolve the Andromeda galaxy’s companions into individual stars and developed the concept of the two types of stellar populations in galaxies. Among his many achievements, Baade is also well known for discovering an area towards our galactic center (M24) which is relatively free of dust, now known as “Baade’s Window.”

Although “Baade’s Window” is a summer sky study, we can take the time this evening to study an area on the opposite side of the sky. Astronomers use a celestial coordinate system based on “hours:minutes:seconds” for east-west location (right ascension – RA) and “degrees” for north-south (declination – DEC) position. It just so happens that should you turn eye, binoculars, or telescope to a RA-DEC location completely complimentary to the center of Baade’s Window (RA=6hrs:16mins, DEC=18.29 degrees) you will find yourself about mid-way between 3.2 magnitude Mu Geminorum and 4.4 magnitude Nu Orionis. And it is precisely there that you will see something that is almost completely the opposite of what can be seen in Baade’s Window – which is to say, “not much.”

Saturday, March 25 – Today in 1655, Titan – Saturn’s largest satellite – was discovered by Christian Huygens. 350 years later, a probe named for Huygens captured the attention of the world as it descended by parachute onto Titan’s surface and sent back information on that distant moon. Huygens also went on to discover Saturn’s ring system in 1655. So while Saturn still rides high in the sky, make your own return visit and tour Saturn’s rings and satellites. The siren song of Titan awaits you!

Also on this date in 1951, 21 cm wavelength radiation from atomic hydrogen in the Milky Way was first detected. 1420 MHz H I, neutral – but non-molecular, hydrogen studies continue to form the basis of large parts of modern radio astronomy. Milky Way H I regions are generally free of stars since they heat the stable hydrogen gases and cause them to emit light. Using 21 cm radio-telescopy, astronomers can map the distribution of non-stellar matter in the interstellar medium – the vast regions of space between the stars. Because radio waves can penetrate dust also found in the interstellar medium, we know much more about the distribution of hydrogen gas in our galaxy than would otherwise be possible.

Although stable hydrogen gas is invisible optically, its presence is especially concentrated along the disk of our galaxy in its vast spiral arms. One such region is associated with the Orion Complex. So take some time to scan the sky due south of 3.4 magnitude Eta Orionis and note how few stars are visible between it and 4.2 magnitude 29 Orionis – some 5 and a half degrees away. Such regions are known to have high concentrations of 21 cm radiation caused by hydrogen gas that has yet to begin coalescing into new Suns such as our own.

Sunday, March 26 – Tonight, let’s have a look at the “Eight-burst Planetary.” But, we have to warn you, it isn’t easy for the northern hemisphere. Start by locating Alpha Hydrae. Now drop more than a hand span due south to Psi in Vela. With Psi centered at low power, you can simply wait a little less than half an hour for NGC 3132 to “drift” into the field, or move due east 7 degrees. Either way should reveal this superb 8th magnitude “Southern Ring Nebula!” Look for a “tilt” in brightness across this 2000 light-year distant ring plus its central star. Use high power – this one is less than half the size of the famed “Northern Ring Nebula” – M57.

May all your journeys be at light speed… ~Tammy Plotner (with Jeff Barbour).

Download our free “What’s Up 2006” ebook, with entries like this for every day of the year.

Greetings, fellow SkyWatchers! Although the Moon is back “en force”, this will still be an exciting week filled with events such as an eclipse, meteor shower and bright, beautiful star clusters.

Here’s what’s up!

Archival image of Percival Lowell. Click to enlarge.
Monday, March 13 – On this day in 1781, Uranus was discovered by William Herschel. 74 years later, in 1855, Percival Lowell was born.

Originally named “the Georgium Sidus,” Uranus was previously catalogued as a faint 6th magnitude star by John Flamsteed in 1690 and designated as 34 Tauri. Herschel came upon this same “star” – then located in the constellation Gemini – while doing a double star search using a homemade 6″ speculum-mirrored reflector. Imagine his surprise when the “star” revealed itself as a small greenish globe!

Percival Lowell was born to a distinguished Boston family with ties to Harvard University. Lowell graduated with honors in mathematics from that same institution in 1876. After traveling throughout the Far East, Lowell’s imagination was set on fire by Giovanni Schiaparelli’s observation of “canali” on Mars. In 1894, Lowell moved to Flagstaff, Arizona and established the Lowell Observatory. Over the next 15 years, he observed Mars with a passion few astronomers could ever hope to match for any single study. During this period, Lowell wrote several books developing the idea of an extinct race of Martians responsible for various artificial features he thought he had observed on the planet’s surface.

Tonight the great Grimaldi, found in the central region of the moon near the terminator is the best lunar feature for binoculars. If you would like to see how well you have mastered your telescopic skills, then let’s start there. About one Grimaldi length south, you’ll see a narrow black ellipse with a bright rim. This is Rocca. Go the same distance again (and a bit east) to spot a small, shallow crater with a dark floor. This is Cruger, and its lava-filled interior is very similar to another study – Billy. Now look between them. Can you see a couple of tiny dark markings? Believe it or not, this is called Mare Aestatis. It’s not even large enough to be considered a medium-sized crater, but is a mare!

Tuesday, March 14 – Today is the birthday of Albert Einstein. Born in 1879, Einstein was later hailed as one of the finest scientific minds of our times. In 1921, Einstein won the Physics Nobel Prize based on work completed 15 years earlier associated with the photoelectric effect – a natural phenomenon now regularly used to accumulate light to image the most distant things in the Universe. Even more significantly, Einstein developed a theory of gravity based on the curvature of space and time caused by the distribution of matter and another theory (of mass-energy conversion) which accounted for the prodigious and sustainable energy output of the stars.

Tonight is the Full Moon. In many cultures, it is known as the “Worm Moon.” As ground temperatures begin to warm and produce a thaw in the northern hemisphere, earthworms return and encourage the return of robins. For the Indians of the far north, this was also considered the “Crow Moon.” The return of the black bird signaled the end of winter. Sometimes it has been called the “Crust Moon” because warmer temperatures melt existing snow during the day, leaving it to freeze at night. Perhaps you may have also heard it referred to as the “Sap Moon.” This marks the time of tapping maple trees to make syrup. To early American settlers, it was called the “Lenten Moon” and was considered to be the last full Moon of winter. For those of us in northern climes, let’s hope so!

But for viewers almost the world over, tonight’s Moon will hold a far greater significance as it passes through a portion of the Earth’s shadow known as the penumbra. Eclipse time? You bet. For viewers in Asia, India and the western portion of Australia, you’ll get to see the Moon pass through this shadow just as it sets for your local time. For Europe and Africa? You’re in luck as the entire event can be seen from your area. For the majority of both North and South America, the eclipse will be underway as the Moon rises, but you can watch it slide out of the shadow long before it sets. Unfortunately, the western-most portion of the Americas will not see anything.

While a penumbral eclipse is not known to be particularly exciting – this one is deep. The edge of the Moon will just graze the inner umbral shadow. As a rule of thumb, remember that the Moon moves about its own diameter each hour, so the very beginning of a penumbral eclipse will be difficult to notice. Slowly and steadily, the coloration will begin to change and even inexperienced SkyWatchers will notice that something is different. It’s a very relaxing experience and we wish you clear skies!

Wednesday, March 15 – Today celebrates the birth of Nicolas Lacaille. Born in 1713, Lacaille’s measurements confirmed the Earth’s equatorial bulge. He also named the fifteen southern constellations, and a lunar feature honors his life’s work. Although the Moon will be bright, we can still have a look at the crater named for Lacaille. Start by heading towards the lunar south central region. Dominating the scene will be brilliant crater Tycho. From there, it’s north to the eastern shores of Mare Nubium, where you will see the bright ring of Thebit. Shallow Lacaille resides to the east and will be a challenge to make out under the low contrast conditions.

While skies remain bright all night, we can still have a look at an open cluster easily located in northeastern Orion. This 5.9 magnitude scattered group of stars may have been first observed by Giovanni Batista Hodierna in the mid-17th century. While bright enough to have been a Messier object, William Herschel added it to his log of discoveries on October 15, 1784, as H VIII.24. Of the 30 known stars associated with this 3,600 light-year distant group, the brightest is 50 million years old. Despite lunar interference, a half-dozen of the cluster’s very brightest members can be seen in small scopes at mid-range powers. Look for NGC 2169 slightly less than a fist width north-northeast of Betelguese and slightly south of Xi and Nu Orionis.

Thursday, March 16 – On this day in 1926, Robert Goddard launched the first liquid-fuel rocket. He first showed his potential in 1907 when a cloud of smoke rose from a powder rocket fired off in the basement of the physics building in Worcester Polytechnic Institute. Needless to say, the school took an immediate interest in the work of this student! Thankfully Robert was not expelled and a lifetime career in rocketry followed. Goddard was also the first person to realize the full spectrum of possibilities associated with missiles and space flight, and his life was completely dedicated to bringing his visions to realization. While most of Goddard’s achievements went unrecognized for many years, tonight we celebrate his name and passion for the space sciences. His first flight may have only gone 12 meters, but forty years later on this same date the Gemini 8 performed the first orbital docking – a maneuver that could have never happened without Goddard’s work!

Tonight, let’s have a look at an ancient walled plain – Gauss. Located north of Mare Crisium, this oblong crater should be divided by the terminator for most viewers tonight. Its east wall will be quite bright and the west wall outlined by a black arc. It is a very old crater, and if you up the magnification, you will see its ruined, cracked floor riddled with numerous small craterlets.

While out, be on watch for the Corona-Australids meteor shower. While the fall rate is low, about 5 to 7 per hour, our friends in the southern hemisphere stand the best chance with this one.

While we’re out, let’s have a look at another fine study on Messier’s list – M50. Described as “heart-shaped” by some observers, those with larger telescopes will see enough members of this 5.9 magnitude open cluster to note two main “petals” of stars arcing outward to the north and southeast. Several tenth magnitude stars congregate toward the center of this 3,200 light-year distant cluster while numerous 11th and 12th magnitude members dance around them in chains and arcs. Look for at least one luminous red giant and a half dozen yellow giants among this 80 million year-old, 20 light-year diameter study.

Friday, March 17 – On this day in 1958, the first solar-powered spacecraft was launched. Christened Vanguard 1, it was an engineering test satellite. From its orbital position, the data taken from its transmissions helped to refine the true shape of the Earth.

While out observing, turn a scope towards Saturn and see if you can begin to make out faint structure in the ring system. On a fine night of “seeing,” you should easily be able to make out the shadow of the planet’s globe cast the planet casts against its posterior ring plane. Look for the shadow of the ring itself softening the view of the planet’s northern equatorial region.

As the Moon rises tonight, look for bright Spica to accompany it. For some lucky viewers, this will be an occultation! Please check with IOTA for details in your area.

Saturday, March 18 – Today in 1965, the first spacewalk was performed by Alexei Leonov onboard the Soviet Voskhod spacecraft. The “walk” lasted around 20 minutes and Alexei had problems re-entering the spacecraft because his space suit had inflated. Imagine his fear as he let air leak out of his suit in order to squeeze back inside. Later when the crew of two landed off target in the heavily forested Ural Mountains, the pair had to spend the night in the woods surrounded by wolves. It took over twenty-four hours before they were located, then workers had to chop their way through the forest to recover them on skis. Brave men on the frontiers of human exploration of space!

Tonight let’s honor their courage by going after something really tough – but certainly not dangerous. Start with Castor and head 3 degrees north-northeast to center on 4.9 magnitude Omicron Geminorum. Now move north another 4 degrees to locate a widely spaced east-west oriented pair of 8th magnitude stars in the constellation Lynx. Look nearby for the faint whisper of luminosity associated with one of the most fascinating studies in the heavens – 10.4 magnitude globular cluster NGC 2419 – the famed “Intergalactic Wanderer.”

First discovered by William Herschel on New Year’s Eve 1788, the Intergalactic Wanderer may or may not just be “passing through” the Milky Way region. – Even as a member of our galaxy’s entourage of clusters and satellite dwarf galaxies, it is one of the most distant. Outside of our own galaxy at around 300,000 light-years!

Small scopists take heart. NGC 2419 can be seen on dark sky occasions in instruments as small as a spotting scope – although you will need to avert your vision to see it. How is that possible? NGC 2419 is intrinsically one of the brightest globular clusters we know of. Be sure to catch this one before moonrise!

Sunday, March 19 – With time to spare before Luna lights up the night, let’s go south and locate a fine reflecting nebula – NGC 2467 – in northern Puppis. Sometimes referred to as the “skull and crossbones nebula,” this billowing cloud of gas and dust is easily found less than a finger-width south-southeast of 3.5 magnitude Xi Puppis. Even a small telescope will find this expansive, star-studded emission nebula a real beauty! Those with larger apertures should look for neighboring splotches of nebulosity illuminated by small groupings of stars – some of which are part of a newly forming open cluster.

Keep in mind while observing NGC 2467 that we are seeing it from a great distance. At 17,000 light-years, this expansive region of star formation is some 10 times farther away than the Great Nebula in Orion. If it were the same distance away, NGC 2467 would dwarf M42!

May all your journeys be at light speed… ~Tammy Plotner. Additional writing by Jeff Barbour @ astro.geekjoy.com.