Category: What’s Up

Monday, July 16 – Today in 1850 at Harvard University, the first photograph of a star (other than the Sun) was made. The honors went to Vega! In 1994, an impact event was about to happen as nearly two dozen fragments of Comet Shoemaker-Levy 9 were speeding their way to the surface of Jupiter. The result was spectacular, and the visible features left behind on the planet’s atmosphere were the finest ever recorded. Why not take the time to look at Jupiter again tonight while it still holds good sky position? No matter where you observe from, this constantly changing planet offers a wealth of things to look at – be it the appearance of the Great Red Spot, or just the ever changing waltz of the Galilean moons. Tonight the Moon and Saturn will not only be close – but very close! Be sure to check IOTA information for a visible occultation event!

Now let’s return again to the oblate and beautiful M19 and drop two fingerwidths south for another misshapen globular – M62.

At magnitude 6, this 22,500 light-year distant Class IV cluster can be spotted in binoculars, but comes to wonderful life in the telescope. First discovered by Messier in 1771, Herschel was the first to resolve it and report on its deformation. Because it is so near to the galactic center, tidal forces have “crushed” it – much like M19. You will note when studying in the telescope that its core is very off center. Unlike M19, M62 has at least 89 known variable stars – 85 more than its neighbor – and the dense core may have undergone collapse. A large number of X-ray binaries have also been discovered within its structure, perhaps caused by the close proximity of stellar members. Enjoy it tonight!

Tuesday, July 17 – Tonight the Moon has returned in a position to favor a bit of study. Start by checking IOTA information for a possible visible occultation of Regulus, and look for Saturn quite nearby as the slender crescent graces the early evening skies.

Although poor position makes study difficult during the first few lunar days, be sure to look for the ancient impact Vendelinus just slightly south of central. Spanning approximately 150 kilometers in diameter and with walls reaching up to 4400 meters in height, lava flow has long ago eradicated any interior features. Its old walls hold mute testimony to later impact events as you view crater Holden on the south shore and much larger Lame on the northeast edge and sharp Lohse northwest. Mark your challenge list!

If you’re up to another challenge tonight, let’s go hunting Herschel I.44, also known as NGC 6104. You’ll find this 9.5 magnitude globular cluster around two fingerwidths northeast of Theta Ophiuchi and a little more than a degree due east of star 51 (RA 17 38 36.93 Dec -23 54 31.5).

Discovered by William Herschel in 1784 and often classed as “uncertain,” today’s powerful telescopes have placed this halo object as a Class VIII and given it a rough distance from the galactic center of 8,800 light-years. Although neither William nor John could resolve this globular, and they listed it originally as a bright nebula, studies in 1977 revealed a nearby suspected planetary nebula named Peterson 1. Thirteen years later, further study revealed this to be a symbiotic star.

Symbiotic stars are a true rarity – not a singular star at all, but a binary system. A red giant dumps mass towards a white dwarf in the form of an accretion disc. When this reaches critical mass, it then causes a thermonuclear explosion resulting in a planetary nebula. While no evidence exists that this phenomenon is physically located within metal-rich NGC 6401, just being able to see it in the same field makes this journey both unique and exciting!

Wednesday, July 18 – On this day 27 years ago, India launched its first satellite (Rohini 1), and 31 years ago in the United States Gemini 10 launched carrying John Young and Michael Collins to space. Tonight we’ll launch our imaginations as we view the area around Mare Crisium and have a look at this month’s lunar challenge – Macrobius. You’ll find it just northwest of the Crisium shore…

Spanning 64 kilometers in diameter, this Class I impact crater drops to a depth of nearly 3600 meters – about the same as many of our earthly mines. Its central peak rises up 1100 meters, and may be visible as a small speck inside the crater’s interior. Be sure to mark your lunar challenges and look for other features you may have missed before!

Since the moonlight will now begin to interfere with our globular cluster studies, let’s waive them for a while as we take a look at some of the region’s most beautiful stars. Tonight your goal is to locate Omicron Ophiuchi, about a fingerwidth northeast of Theta. At a distance of 360 light-years, this system is easily split by even small telescopes. The primary star is slightly dimmer than magnitude 5 and appears yellow to the eye. The secondary is near 7th magnitude and tends to be more orange in color. This wonderful star is part of many double star observing lists, so be sure to note it!

Thursday, July 19 – Today in 1846, Edward Pickering was born. Although his name is not well known, he became a pioneer in the field of spectroscopy. Pickering was the Harvard College Observatory Director from 1876 to 1919, and it was during his time there that photography and astronomy began to merge. Known as the Harvard Plate Collection, these archived beginnings still remain a valuable source of data.

With plenty of Moon to explore tonight, why don’t we try locating an area where many lunar exploration missions made their mark? Binoculars will easily reveal the fully disclosed areas of Mare Serenitatis and Mare Tranquillitatis, and it is where these two vast lava plains converge that we will set our sights. Telescopically, you will see a bright “peninsula” westward of where the two conjoin which extends toward the east. Just off that look for bright and small crater Pliny. It is near this rather inconspicuous feature that the remains Ranger 6 lie forever preserved where it crashed on February 2, 1964.

Unfortunately, technical errors occurred and it was never able to transmit lunar pictures. Not so Ranger 8! On a very successful mission to the same relative area, this time we received 7137 “postcards from the Moon” in the last 23 minutes before hard landing. On the “softer” side, Surveyor 5 also touched down near this area safely after two days of malfunctions on September 10, 1967. Incredibly enough, the tiny Surveyor 5 endured temperatures of up to 283 degrees F, but was able to spectrographically analyze the area’s soil… And by the way, it also managed to televise an incredible 18,006 frames of “home movies” from its distant lunar locale.

When you’re finished, why not have a look at something that would make Edward Pickering proud? He enthusiastically encouraged amateur astronomers, and founded the American Association of Variable Star Observers – so set your sights on RR Scorpius about two fingerwidths northeast of Eta and less than a fingerwidth southwest M62 (RA 16 56 37.84 Dec -30 34 48.2). This very red Mira type can reach as high as magnitude 5 and drop as low as 12 in about 280 days!

Friday, July 20 – Today was a busy day in astronomy history! In 1969, the world held its breath as the Apollo 11 lander touched down and Neil Armstrong and Edwin Aldrin became the first humans to touch the lunar surface. We celebrate our very humanity because even Armstrong was so moved that he messed up his lines! The famous words were meant to be “A small step for a man. A giant leap for mankind.” That’s nothing more than one small error for a man, and mankind’s success continued on July 20, 1976 when Viking 1 landed on Mars – sending back the first images ever taken from that planet’s surface.

Tonight let’s celebrate 36 years of space exploration and walk on the Moon where the first man set foot. For SkyWatchers, the dark round area you see on the northeastern limb is Mare Crisium and the dark area below that is Mare Fecunditatis. Now look mid-way on the terminator for the dark area that is Mare Tranquillitatis. At its southwest edge, history was made.

In binoculars, trace along the terminator where the Caucasus Mountains stand – and then south for the Apennines and the Haemus Mountains. As you continue towards the center of the Moon, you will see where the shore of Mare Serenitatis curves east, and also the bright ring of Pliny. Continue south along the terminator until you spot the small, bright ring of Dionysius along the edge of Mare Tranquillitatis. Just to the southwest, you may be able to see the soft rings of Sabine and Ritter. It is near here where the base section of the Apollo 11 landing module – Eagle – lies forever enshrined in “magnificent desolation.”

For telescope users, the time is now to power up! See if you can spot small craters Armstrong, Aldrin and Collins just east. Even if you cannot, the Apollo 11 landing area is about the same distance as Sabine and Ritter are wide to the east-southeast.

Even if you don’t have the opportunity to see it tonight, take the time during the next couple of days to point it out to your children, grandchildren, or even just a friend… The Moon is a spectacular world and we’ve been there!

Saturday, July 21 – Today in 1961, Mercury 4 was launched, sending Gus Grissom into suborbital space on the second manned flight, and he returned safely in Liberty Bell 7.

Long before the Sun sets, look for the Moon to appear in the still-blue sky. As it darkens, watch for brilliant blue/white Spica to be around a fingerwidth north of the Moon. Have you ever wondered if there was any place on the lunar surface that hasn’t seen the sunlight? Then let’s go searching for one tonight…

Our first order of business will be to identify crater Albategnius. Directly in the center of the Moon is a dark floored area known as Sinus Medii. South of it will be two conspicuously large craters – Hipparchus to the north and ancient Albategnius to the south. Trace along the terminator toward the south until you have almost reached its point (cusp) and you will see a black oval. This normal looking crater with the brilliant west wall is equally ancient crater Curtius. Because of its high southern latitude, we shall never see the interior of this crater – and neither has the Sun! It is believed that the inner walls are quite steep and that Curtius’ interior has never been illuminated since its formation billions of years ago. Because it has remained dark, we can speculate that there may be “lunar ice” pocketed inside its many cracks and rilles that date back to the Moon’s formation!

Because our Moon has no atmosphere, the entire surface is exposed to the vacuum of space. When sunlit, the surface reaches up to 385 K, so any exposed “ice” would vaporize and be lost because the Moon’s gravity cannot hold it. The only way for “ice” to exist would be in a permanently shadowed area. Near Curtius is the Moon’s south pole, and the Clementine spacecraft’s imaging showed around 15,000 square kilometers in which such conditions could exist. So where did this “ice” come from? The lunar surface never ceases to be pelted by meteorites – most of which contain water ice. As we know, many craters were formed by just such impacts. Once hidden from the sunlight, this “ice” could remain for millions of years!

Sunday, July 22 – Tonight instead of lunar exploration, we will note the work of Friedrich Bessel, who was born on this day in 1784. Bessel was a German astronomer and mathematician whose functions, used in many areas of mathematical physics, still carry his name. But, you may put away your calculator, because Bessel was also the very first person to measure a star’s parallax. In 1837, he chose 61 Cygni and the result was no more than a third of an arc second. His work ended a debate that had stretched back two millennia to Aristotle’s time and the Greek’s theories about the distances to the stars.

Although you’ll need to use your finderscope with tonight’s bright skies, you’ll easily locate 61 between Deneb (Alpha) and Zeta on the eastern side. Look for a small trio of stars and choose the westernmost. Not only is it famous because of Bessel’s work, but it is one of the most noteworthy of double stars for a small telescope. 61 Cygni is the fourth nearest star to Earth, with only Alpha Centauri, Sirius, and Epsilon Eridani closer. Just how close is it? Try right around 11 light-years.

Visually, the two components have a slightly orange tint, are less than a magnitude apart in brightness and have a nice separation of around 30″ to the south-southeast. Back in 1792, Piazzi first noticed 61’s abnormally large proper motion and dubbed it “The Flying Star.” At that time, it was only separated by around 10″ and the B star was to the northeast. It takes nearly 7 centuries for the pair to orbit each other, but there is another curiosity here. Orbiting the A star around every 4.8 years is an unseen body that is believed to be about 8 times larger than Jupiter. A star – or a planet? With a mass considerably smaller than any known star, chances are good that when you view 61 Cygni, you’re looking toward a distant world!

Monday, July 9 – If you’re up before dawn this morning, be sure to step outside and look at the waning Moon accompanied by ruddy Mars about 5 degrees to the south. This is definitely worth getting up early for!

Tonight we will hustle off to explore a single small globular – M80. Located about 4 degrees northwest of Antares (about two fingerwidths), this little globular cluster is a powerpunch. Located in a region heavily obscured by dark dust, M80 will shine like an unresolvable star to small binoculars and reveal itself to be one of the most heavily concentrated globulars to the telescope.

Discovered within days of each other by Messier and Méchain, respectively, in 1781, this intense Class I globular cluster is around 36,000 light-years distant. In 1860, M80 became the first globular cluster to host a nova. As stunned scientists watched, a centrally located star brightened to magnitude 7 over a period of days and became known as T Scorpii. The event then dimmed more rapidly than expected, making observers wonder exactly what they had seen.

Since most globular clusters contain stars all of relatively the same age, the hypothesis was put forward that perhaps they had witnessed an actual collision of stellar members. Given that the cluster contains more than a million stars, the probability is that some 2700 collisions of this type may have occurred during M80’s lifetime.

On this day in 1979, Voyager 2 quietly made its closest approach to Jupiter. How about if we take a close approach as well? Enjoy the waltz of the Galileans and all the fine details!

Tuesday, July 10 – Tonight let’s head on out towards two more giants that appear very differently from other recent studies (and from each other) – the same-field binocular pair M10 and M12.Located about half a fistwidth west of Beta Ophiuchi, M12 is the northernmost of this pair. Easily seen as two hazy round spots in binoculars, let’s go to the telescope to find out what makes M12 tick. Since this large globular is much more loosely concentrated, smaller scopes will begin to resolve individual stars from this 24,000 light-year distant Class IX cluster. Note there is a slight concentration toward the core region, but for the most part the cluster appears fairly even. Large instruments will resolve out individual chains and knots of stars.

Now let’s drop about three and a half degrees southeast and check out Class VII M10. What a difference in structure! Although they seem to be close together and close in size, the pair is actually separated by some 2,000 light-years. M10 is a much more concentrated globular showing a brighter core region to even the most modest of instruments. This compression of stars is what classifies one type of globular cluster from another, and M10 appears brighter, not because of this compression, but because it is about 2,000 light-years closer.

Wednesday, July 11 – For hard core observers, tonight’s globular cluster study will require at least a mid-aperture telescope, because we’re staying up a bit later to go for a same-low-power-field pair – NGC 6522 and NGC 6528. You will find them easily at low power just a breath northwest of Gamma Sagittarii – better known as Al Nasl – the tip of the “teapot’s” spout. Once located, switch to higher power to keep the light of Gamma out of the field and let’s do some studying.

The brighter, and slightly larger, of the pair to the northeast is Class VI NGC 6522. Note its level of concentration compared to Class V NGC 6528. Both are located around 2,000 light-years away from the galactic center and seen through a very special area of the sky known as “Baade’s Window” – one of the few areas towards our galaxy’s core region not obscured by dark dust. While they are similar in concentration and distance, NGC 6522 has a slight amount of resolution towards its edges while NGC 6528 appears more random.

While both NGC 6522 and NGC 6528 were discovered by Herschel on July 24, 1784, and both are the same distance from the galactic core – they are very different. NGC 6522 has an intermediate metallicity. At its core, the red giants have been depleted – stripped tidally by evolving blue stragglers. It is possible that core collapse has already occurred. NGC 6528, however, contains one of the highest metal contents of any known globular cluster collected in its bulging core!

Thursday, July 12 – Tonight we’re going to move back toward Ophiuchus and a globular cluster unlike any that we’ve seen so far – M19. First locate Antares. About a fistwidth to the east you will see Theta Ophiuchi, with fainter star 44 to its northwest and multiple system 36 to the southeast. Move around two degrees to the west of 36 and let’s check it out.

With a visual magnitude of 6.8, this class VIII globular cluster can be seen with small binoculars, but requires a telescope to begin to take on form. Discovered by Messier in 1764, M19 is the most oblate globular known. Harlow Shapely, who studied globular clusters and cataloged their elliptical natures, estimated that there were about twice as many stars along the major axis as along the minor. This stretching of the cluster from its accepted round shape may very well have to do with its proximity to the Galactic Center – a distance of only about 5,200 light-years. This makes it only a tiny bit more remote from us than the very center of the Milky Way!

Very rich and dense, even smaller telescopes can pick up the faint blue tinge to this globular cluster. It is definitely one of the more interesting, due to its shape, but for the adventurous? There are two more. The Class VI NGC 6293 is about a degree and a half to the east-southeast and is far brighter than you might expect. It is much rounder, and is more concentrated directly in the core than its companion. Now move about a degree and a half to the north-northeast of M19 to find dimmer Class IX NGC 6284. Although it is the same size as NGC 6293, look how much more loosely this one is constructed!

Friday, July 13 – Today is Friday the 13th. If you’re not superstitious, but only having bad luck at finding some of these globular clusters – then how about if we take a look at one that’s incredibly easy to find? All you have to know is Antares and go west…

Just slightly more than a degree away you find a major globular cluster perfectly suited for every size telescope and binoculars – M4. This 5th magnitude Class IX cluster can even be spotted unaided from a dark location! In 1746 Philippe Loys de Chéseaux happened upon this 7200 light-year distant beauty – one of the nearest to us. It was also included in Lacaille’s catalog as object I.9 and in Messier’s in 1764. Much to Charles’ credit, he was the first to resolve it!

As one of the most loose, or open, globular clusters, M4 would be tremendous if we were not looking at it through a heavy cloud of interstellar dust. To binoculars, it is easy to pick out a very round, diffuse patch – yet it will begin resolution with even a small telescope. Large telescopes will also easily see a central “bar” of stellar concentration across M4’s core region, which was first noted by Herschel.

As an object of scientific study, the first millisecond pulsar was discovered within M4 in 1987 – one which is 10 times faster than the pulsar contained within the Crab Nebula. Photographed by the Hubble Space Telescope in 1995, M4 was found to contain white dwarf stars – the oldest in our galaxy – with a planet orbiting one of them! A little more than twice the size of Jupiter, this planet is believed to be as old as the cluster itself. At 13 billion years, it would be three times the age of the Sol system!

Saturday, July 14 – Today in 1965, Mariner 4 became the first spacecraft to perform a flyby of Mars. If you’re up early, be sure to salute the Red Planet! Tonight at sunset, look for the beautiful visages of Venus and Regulus about a degree apart. Something for both the morning and evening SkyWatcher…

Tonight is New Moon and what better time to look for some alternate catalog objects? Let’s start by Herschel hunting while we continue on our globular cluster studies. Our first stop is to return to brilliant Antares and head one-half degree northwest for the Bennett list cluster NGC 6144 (RA 16 27 14.14 Dec -26 01 29.0).

Originally discovered by Herschel in 1784 and labeled as H VI.10, this 9th magnitude Class II globular is around 8500 light-years from the galactic core. While it is only about one-third the size of M4, it is also three times more distant from our solar system. If you have trouble spotting it, try high magnification to keep Antares’ glare at bay. Situated in the Rho Ophiuchi dust cloud, NGC 6144 has at least one slow variable of the RR Lyrae type.

Now drop a little more than a fistwidth south of Antares for NGC 6139 (RA 16 27 40.43 Dec -38 50 55.6). Discovered by James Dunlop in 1820 and cataloged as Dun 536, this 9th magnitude Class II globular is much further from the galactic center at a distance of 11,700 light-years. Within the gravitational pull of this low metallicity cluster, at least six RR Lyrae type variables still cling to their host.

Now that we’ve seen two very concentrated globular clusters, let’s look at one that isn’t even classed. Drop a fingerwidth south of Lambda Scorpii for NGC 6380 (RA 17 34 28.00 Dec -39 04 09.0). This 11th magnitude globular is a challenge! Also discovered by Herschel and listed as h 3688, this one is also known as Tonantzintla 1 – or Ton 1. It’s so vague that it wasn’t even classed as a globular cluster until research with a photographic plate! It’s very metal-rich and contains red giants at its bulging heart… What’s left of it!

Sunday, July 15 – Tonight while dark skies are still in our favor, let’s start off north in Hercules for a look at another globular study – M92. Although in a relatively open field for starhoppers, it’s not too hard to find if you can imagine it as the apex of a triangle with northern keystone stars – Eta and Pi – as the base.

At near magnitude 6, Class IV M92 was discovered by Johann Bode in 1777 and cataloged as Bode 76. Independently recovered by Messier in 1781 and resolved by Herschel in 1783, this bright, compact globular is around 26,700 light-years away and may be from 12-16 billion years old. It contains 14 RR Lyrae variables among its 330,000 stars, and a very rare eclipsing binary.
Viewable unaided under the right conditions and very impressive in even small binoculars, M92 is a true delight to even the smallest of telescopes. It has a very bright and unresolvable core with many outlying stars that are easily revealed. Larger scopes will appreciate its fiery appearance!

Now let’s hop south to Beta Ophiuchi to have a look at NGC 6426, about a fingerwidth south. There’s a very good reason why you’ll want to at least try with Herschel II.587! It’s even older than M92…

Discovered and cataloged by Sir William in 1786, this 11th magnitude globular Class IX globular looks destroyed in comparison. At 67,500 light-years away, it’s far more than twice the distance from us as is M92! Residing 47,600 light-years from the galactic center, NGC 6426 contains 15 RR Lyrae variables (3 of which are newly discovered) and is the most metal-poor globular known. So what’s the relation to M92? It’s even older!

Forget about finding this one in binoculars and very small telescopes. For the mid-sized scope you’ll find it conveniently located about halfway between Beta and Gamma Ophiuchi – but it’s not easy. Faint and diffuse, a large telescope is required to begin resolution.

Monday, July 2 – Orbiting in space 40 years ago, the Vela 3 and 4 satellites were quietly keeping watch on Earth’s nuclear test ban treaty. The Vela satellites were greatly successful and far exceeded their life expectancy. While checking data on this day just before the launch of the fifth Vela, scientists found an event recorded by Vela 4 – an event also strong enough to trigger a response from the Vela 3 satellite. While placement wasn’t accurate enough at the time to pinpoint the source, the scientists realized they had caught the first recorded gamma ray burst.

While very little is known about these mysterious events, we do know that they occur about once a day with a photon energy of 100 million electron volts. While some of them occur in our own Milky Way, science is unclear about the source of more distant explosions – and over 800 have been charted on a single map! One such source for gamma rays is a special type of star known as a Wolf-Rayet – a hot, huge star which is undergoing significant mass loss and exposing its central core.

Tonight for more southern viewers, take the time to look up one such incredible system, IC 4406. You’ll find it about 5 degrees northwest of Alpha Lupi, or just about a fingerwidth northwest of the Tau collection (RA 14 22 26.28 Dec -44 09 04.3). This roughly 10th magnitude planetary nebula is sometimes referred to as the “Retina Nebula” for its photographic resemblance to the human retina. This square appearing patch is a Wolf-Rayet nebula and color photographs show evidence of gamma rays as green sparkles!

Tuesday, July 3 – If you’re up before dawn, this morning would be a great opportunity to easily find Neptune around one degree north of the Moon.

Tonight for all observers, let’s take a closer look at the fascinating constellation of Lupus southwest of brilliant Antares. While more northerly latitudes will see only roughly half of this constellation, it sits well at this time of year for those in the south. So why bother?

Cutting through our Milky Way galaxy at a rough angle of about 18 degrees is a disc shaped zoned called Gould’s Belt. Lupus is part of this area, and its perimeter contains star-forming regions that came to life about 30 million years ago when a huge molecular cloud of dust and gas compressed – much like in the Orion area. In Lupus we find Gould’s Belt extending above the plane of the Milky Way!

Return again to the beautiful Theta and head around 5 degrees west for NGC 5986 (RA 15 46 03.44 Dec -37 47 10.1). It’s a 7th magnitude globular cluster which can be spotted with binoculars with good conditions. While this Class VII cluster is not particularly dense, many of its individual stars can be resolved in a small telescope.

Now sweep the area north of NGC 5986 (RA 17 57 06.00 Dec -37 05 -0.0) and tell me what you see. That’s right! Nothing. This is the dark nebula B 288 – a cloud of dark, obscuring dust which blocks incoming starlight. Look carefully at the stars you can see and you’ll notice they appear quite red. Thanks to B 288, much of their emitted light is absorbed by this region, providing us with a pretty incredible on-the-edge view of something you can’t see – a Barnard dark nebula.

Wednesday, July 4 – Did you know that celestial fireworks occurred in 1054 on this day? It is believed that the bright supernova recorded by Chinese astronomers occurred at this point in history, and today we know its remnants as M1 – the “Crab Nebula.”

But could such an event happen again in our own celestial “backyard?” Look no further than HR 8210 (RA 21 26 26.66 Dec +19 22 32.3). It may be nothing more than a white dwarf star hiding out in late night Capricornus, but it’s a star that has run out of most of its fuel. This rather ordinary binary system has a companion white dwarf star that’s 1.15 times the mass of our Sun. As the companion also expends its fuel, it will add mass to HR 8210 and push it over the Chandrasekhar limit – the point of no return in mass. This will result in a supernova event located only 150 light-years away from our solar system…50 light-years too close for comfort!

470 light-years away in the Gould Belt, and roughly 1.5 million years ago, a similar massive star exploded in the Upper Scorpius association. No longer able to resist its own gravitational mass by nuclear fusion, it unleashed a supernova event which left its evidence as a layer of iron here on Earth, and may have caused a certain amount of extinction when its gamma rays directly affected our ozone layer.

Take a long look at Antares tonight – for it is part of that association of stars, and is no doubt a massive red star also poised at the edge of extinction. At a safe distance of 500 light-years, you’ll find this pulsing red variable equally fascinating to the eye as well as to the telescope. Unlike HD 8210, Alpha Scorpii also has a companion star which can be revealed to small telescopes under steady conditions. Discovered on April 13, 1819 during a lunar occultation, this 6.5 magnitude green companion isn’t the easiest to split from such a bright primary – but it’s certainly fun to try!

Thursday, July 5 – If the outer planets call you, then make a date before dawn to catch Uranus. Easily spotted in binoculars, the seventh planet from the Sun can be found about 1.7 degrees south of the Moon.

Tonight let’s have a look at a real little powerpunch globular cluster located in northern Lupus – NGC 5824. Although it’s not an easy star hop, you’ll find it about 7 degrees southwest of Theta Librae and exactly the same distance south of Sigma Librae (RA 15 03 58.50 Dec -33 04 03.9). Look for a 5th magnitude star in the finderscope to guide you to its position southeast.

As a Class I globular cluster, you won’t find any that is more concentrated than this. Holding a rough magnitude of 9, this little beauty has a deeply concentrated core region that is simply unresolvable. Discovered by E. E. Barnard in 1884, it enjoys its life in the outer fringes of the galactic halo about 104 light-years away from Earth, and contains many recently discovered variable stars. Oddly enough, this metal poor globular may have been formed by a merger. In researching evidence found about NGC 5824’s stellar population, it is believed that two less dense and differently-aged globulars may have approached one another at a low velocity and combined to form this ultra-compact structure.

Be sure to mark your observing notes on this one! It also belongs to the Bennett catalog and is part of many globular cluster studies. Enjoy…

Friday, July 6 – Today in 1687, Isaac Newton’s “Principia” was first published with the help of Edmund Halley. Although Newton was indeed a very strange man with a highly checkered history, one of the keys to Newton’s work with the theory of gravity was the idea that one body could attract another across the vastness of space.

Now let’s have a look at things gravitationally bound as we start at Eta Lupi, which is a fine double star that can even be resolved with binoculars. Look for the 3rd magnitude primary and 8th magnitude secondary separated by a wide 15″. You’ll find it by staring at Antares and heading due south two binocular fields to center on bright H and N Scorpii – then one binocular field southwest.

When you are done, hop another roughly five degrees southeast to encounter the fine open cluster NGC 6124. Discovered by Lacaille, and known as object I.8, this 5th magnitude open cluster is also known as Dunlop 514, as well as Melotte 145 and Collinder 301. Situated about 19 light-years away, it will show as a fine, round, faint spray of stars to binoculars and be resolved into about 100 stellar members to larger telescopes.

While NGC 6124 is on the low side to northern observers, it’s worth the wait for it to hit best position and at least try! Be sure to mark your notes, since this delightful galactic cluster is a Caldwell object and a southern skies binocular award.

Saturday, July 7 – Tonight for unaided observers, let’s begin by identifying Zeta Ophiuchi, the centermost in a line of stars marking the edge of the constellation of Ophiuchus, about a handspan north of Antares. As a magnificent 3rd magnitude blue/white class O, this hydrogen fusing dwarf is 8 times larger than our own Sun. Hanging out some 460 light-years away, it is dulled by the interstellar dust of the Milky Way and would shine two full magnitudes brighter if it were not obstructed. Zeta is a “runaway star” – a product of a one-time supernova event in a double star system. Now roughly halfway through its 8 million year life span, the same fate awaits this star!

Now point binoculars or small scopes about three fingerwidths south to have a look at Phi Ophiuchi. This is a spectroscopic double star, but it has several delightful visual companions!

Almost in between these two bright stars is our telescopic target for tonight – M107. Discovered by Pierre Méchain in 1782, but only added to the Messier catalog in 1947, it’s probably one of the last of the Messier objects to be discovered, and it wasn’t resolved into individual stars until studied by Herschel in 1793.

M107 isn’t the most impressive of globulars, but this Class X is notable as a faint, diffuse area with a core region in binoculars, and is surprisingly bright in a small telescope. It’s a curious cluster, for some believe it contains dark, dust-obscured areas which make it unusual. Located around 21,000 light-years away, this little beauty contains around 25 known variable stars. Visually, the cluster begins to resolve around the edges to mid-aperture and the structure is rather loose. If sky conditions permit, the resolution of individual chains at the globular’s edges make this it well worth a visit to log as Herschel IV.40!

Sunday, July 8 – Tonight let’s continue on our journey through the galactic halo and pick up the Class VIII globular cluster M9. You’ll find it located around two fingerwidths east of Eta Ophiuchi.

Discovered by Messier in 1764, this particular globular cluster is one of the nearest to our galactic center and is around 2,600 light-years away from our solar system. Now let’s study differences – check out the contrast between this small globular compared to last night’s M107. With M9 we’re seeing not only a strong central concentration, but a slight oval shape. This change in structure is caused by the strong absorption of starlight by dust along its northwest edge. Of its huge stellar population, only a dozen or so variable stars are known in M9, which is rather few for a cluster of its size. Visually, it appears more compact than M107, and slightly oblate. Rather than chains of stars resolving at the edges, M9 appears to have larger, individual stars in a random pattern – while M107 appears to have a solid core!

For those with larger scopes, you also have the opportunity to study two more globulars that are nearby – Class II NGC 6356 about a degree to the northeast and Class IV NGC 6342 to the southeast. You will find NGC 6356 to be rather small – but bright and concentrated. NGC 6342 appears to be even smaller and far less distinct. Compare them both to the structure of M9 and you will find 6356 to be the most concentrated of the three…a “class” act!

Monday, June 25 – Today celebrates the birth of Hermann Oberth – who has often been considered the father of modern rocketry. Born in Transylvania in 1894, Oberth was a visionary who was convinced space travel would one day be possible. Inspired by the works of Jules Verne, Oberth studied rockets and wrote many books devoted to the possibility of achieving spaceflight. He was the first to conceive of rocket “stages” – allowing vehicles to expend their fuel and lose dead weight. But tonight you won’t need one of Oberth’s rockets to travel to the Moon, as we look at the northeast shore of Mare Cognitum and the Apollo 14 mission landing site – Fra Mauro.

As craters go, 3.9 billion year old Fra Mauro is on the shallow side and spans 95 kilometers. At some 730 meters deep, standing at one of its walls would be like standing at the bottom of the Grand Canyon… Yet, time has so eroded this crater that its west wall is completely missing and its floor is covered with fissures.

Even though ruined Fra Mauro seems like a foreboding place to land a manned mission, it remained high on the priority list because it is geologically rich. Ill-fated Apollo 13 was to land in a formation north of the crater formed by ejecta belonging to the Imbrium Basin – material that had already been mapped telescopically. By returning samples of this material from deep within the Moon’s crust, scientists could then determine the exact time these changes came about.

As you view Fra Mauro tonight, picture yourself in a lunar rover traversing this barren ground and rock-strewn landscape thrown out from a long-ago impact. How willing would you be to take on the vision of Oberth and travel to another world?

Tuesday, June 26 – On this day in 1949, asteroid Icarus was discovered on a 48-inch Schmidt plate made nine months after that telescope went into operation, and just prior to the beginning of the multi-year National Geographic-Palomar Sky Survey. The asteroid was found to have a highly eccentric orbit and a perihelion distance of just 27 million kilometers, closer to the Sun than Mercury, giving it its unusual name. It was just 6.4 million kilometers from Earth at the time of discovery, and variations in its orbital parameters have been used to determine Mercury’s mass and test Einstein’s theory of general relativity.

But, today is even more special because it is the birthday of none other than Charles Messier, the famed French comet hunter. Born in 1730, Messier is best known for cataloging the 100 or so bright nebulae and star clusters that we now refer to as the Messier objects. The catalog was intended to keep both Messier and others from confusing these stationary objects with possible new comets.

Tonight let’s venture towards the south shore of Palus Epidemiarum to have a high power look at crater Capuanus. Named for Italian astronomer Francesco Capuano di Manfredonia, this 60 kilometer wide crater boasts a still tall southwest wall, but the northeast one was destroyed by lava flow. At its highest, it reaches around 1900 meters above the lunar surface, yet drops to no more than 300 meters at the lowest. Look for several strikes along the crater walls as well as more evidence of a strong geological history. To its north is the Hesiodus Rima…a huge fault line that extends 300 kilometers across the surface!

Now see how many Messier objects that you can capture and wish Charles a happy 263rd birthday!

Wednesday, June 27 – As we wait on the sky to darken tonight, let’s start our adventures by taking a close look at crater Kepler. Situated just north of central along the terminator tonight, this great crater named for Johannes Kepler only spans 32 kilometers, but drops to a deep 2750 meters below the surface. This class I crater is a geological hotspot!

As the very first to be mapped by the U.S. Geological Survey, the area around Kepler contains many smooth lava domes that extend no more than 30 meters or so above the plains. According to records, in 1963 a glowing red area was spotted near Kepler and extensively photographed. Normally one of the brightest regions of the Moon, the brightness value at the time nearly doubled! Although it was rather exciting, scientists later determined the phenomenon was caused by high energy particles from a solar flare reflecting from Kepler’s high albedo surface. In the days ahead all details around Kepler will be lost, so take this opportunity to have a good look at one awesome small crater!

When skies are dark, it’s time to have a look at the 250 light-year distant silicon star Iota Librae. This is a real challenge for binoculars – but not because the components are so close. In Iota’s case, the near 5th magnitude primary simply overshadows its 9th magnitude companion! In 1782, Sir William Herschel measured them and determined them to be a true physical pair. Yet, in 1940 Librae A was determined to have an equal magnitude companion only .2 arc seconds away…. And the secondary was proved to have a companion of its own that echoes the primary. A four star system!

While you’re out, keep a watch for a handful of meteors originating near the constellation of Corvus. The Corvid meteor shower is not well documented, but you might spot as many as ten per hour.

Thursday, June 28 – Are you ready to study the Moon again tonight? Be sure to look for the “Cow Jumping over the Moon” – but power up with a telescope to study some very wild looking features – lunar lava domes.

North of Aristarchus, west of Promontorium Heraclides, and near the terminator is Rumker – the largest of the lunar lava domes. Only visible when near the terminator, this roughly 77 kilometer diameter “soft hill” ranges anywhere from 60 to 760 meters tall. Although it is not much more than a bump on the lunar surface, it does contain a few summit craters at its highest points. What we are looking at is really an important part of the geology which shaped the Moon’s surface. In all likelihood, Rumker is a shield volcano…in an area of many!

Now continue east towards the prominent crater Marian set in a bright peninsula extending into Sinus Roris and Mare Imbrium. Just southwest are two more – Mons Gruithuisen Gamma (the “Megadome”) and Mons Gruithuisen Delta. While you might not find these features particularly impressive, consider that we’re looking at something only 20 kilometers wide and only meters high!

When you’re finished with your lunar observations, tonight let’s try a challenging double star – Upsilon Librae. This beautiful red star is right at the limit for a small telescope, but quite worthy as the pair is a widely disparate double. Look for the 11.5 magnitude companion to the south in a very nice field of stars!

Friday, June 29 – Today we celebrate the birthday of George Ellery Hale, who was born in 1868. Hale was the founding father of the Mt. Wilson Observatory. Although he had no education beyond his baccalaureate in physics, he became the leading astronomer of his day. He invented the spectroheliograph, coined the word astrophysics, and founded the Astrophysical Journal and Yerkes Observatory. At the time, Mt. Wilson dominated the world of astronomy, confirming what galaxies were and verifying the expanding universe cosmology, making Mt. Wilson one of the most productive facilities ever built. When Hale went on to found Palomar Observatory, the 5-meter (200″) telescope was named for him and dedicated on June 3, 1948. It continues to be the largest telescope in the continental United States.

Now let’s go deep south and have look at an area which once held something almost half a bright as tonight’s Moon and over four times brighter than Venus. Only one thing could light up the skies like that – a supernova.

According to historical records from Europe, China, Egypt, Arabia and Japan, 1001 years ago the very first supernova event was noted. Appearing in the constellation of Lupus, it was at first believed to be a comet by the Egyptians, yet the Arabs saw it as an illuminating “star.”

Located less than a fingerwidth northeast of Beta Lupus (RA 15 02 48.40 Dec -41 54 42.0) and a half degree east of Kappa Centaurus, no visible trace is left of a once grand event that spanned five months of observation beginning in May, and lasting until it dropped below the horizon in September, 1006. It is believed all the force created from the event was converted to energy and very little mass remains. In the area, a 17th magnitude star shows a tiny gas ring and radio source 1459-41 remains our best candidate for pinpointing this incredible event.

Saturday, June 30 – Tonight is the Full Moon – but is it Blue? According to modern folklore, anytime there is a second Full Moon within one calendar month it’s called “blue.” The explanation of the term is a rather long one involving old almanacs, mistakes in literary sources, and even urban legend. No matter if the definition is right or wrong, we can still enjoy a relatively rare occurrence – but how rare is it?

Most of the time a calendar month will only have one Full Moon, yet it’s a given that any event separated by 29 days will eventually catch up to calendar time – around every two and half years. Chances are good that you’ll only see the same pearl colored Moon as always when it rises – but if your area is affected by volcanic eruptions or forest fires – it just might be blue! (But then you’d best be running and not out Moongazing…) This is caused by the light scattering properties of small particles in the atmosphere – much like what causes our daylight skies to be blue, or noctilucent clouds to have their strange colors.

Still got the blues? Then try your hand at a super challenging double – Mu Librae. This pair is only a magnitude apart in brightness and right at the limit for a small telescope. Up the power slowly and look for the companion just to the southwest of the primary. Good luck and mark your observation because Mu’s blues are on many observing lists!

And out of the blue comes a meteor shower! Keep watch tonight for the June Draconids. The radiant for this shower will be near handle of Big Dipper – Ursa Major. The fall rate varies from 10 to 100 per hour, but tonight’s bright skies will toast most of the offspring of comet Pons-Winnecke. On a curious note, today in 1908 was when the great Tunguska impact happened in Siberia. A fragment of a comet, perhaps?

Sunday, July 1 – Today In 1917, the astronomers at Mt. Wilson were celebrating as the 100″ primary mirror arrived. Up until that time, the 60″ Hale telescope (donated by George Hale’s father) was the premier creation of St. Gobrain Glassworks – which was later commissioned to create the blank for the Hooker telescope. Thanks to the funds provided by John D. Hooker (and Carnegie), the dream was realized after years of hard work and ingenuity to create not only a building to properly house it – but the telescope workings as well. It saw “first light” five months later on November 1.

As anxious astronomers waited for this groundbreaking moment, the scope was aimed at Jupiter but the image was horrible – to their dismay, workmen had left the dome open and the Sun had heated the massive mirror! Try as they might to rest until it had cooled – no astronomer slept. Fearful of the worst, sometime around three in the morning they returned again long after Jupiter had set. Pointing the massive scope towards a star, they achieved a perfect image!

Tonight start your stargazing evening off right by having a look at the western skyline at twilight. Venus and Saturn are waltzing together less than a degree apart! Not only is this an eye appealing conjunction to the unaided observer, but a wonderful opportunity to see both planets at once in the same low power telescope field!

While you’re out, take the time to look at lowly Theta Lupi about a fistwidth south-southwest of the mighty Antares. While this rather ordinary looking 4th magnitude star appears to be nothing special – there’s a lesson to be learned here. So often in our quest to look at the bright and incredible – the distant and the impressive – we often forget about the beauty of a single star. When you take the time to seek the path less traveled, you just might find more than you expected. Hiding behind a veil of the “ordinary” lies a trio of three spectral types and three magnitudes in a diamond-dust field. An undiscovered gem….

Monday, June 18 – Mark your calendars for dusk tonight as brilliant Venus dances with the da Vinci Moon. The sparkling planet will be about one half degree south of the crescent and for some locations this could be an occultation! Be sure to check the IOTA website for locations and times in your area.

No special equipment is needed to see this event, and thanks to Leonardo da Vinci we can see the ghostly effect on the Moon as quite logical. He was the first to theorize that sunlight was reflecting off the Earth and illuminating the portion of the Moon not lit by the Sun. We more commonly refer to this as “Earthshine” – but no matter how scientific the explanations are for this phenomena, its appearance remains beautiful.

While you’re out tonight, take a look at the skies for a circlet of seven stars that reside about halfway between orange Arcturus and brilliant blue/white Vega. This quiet constellation is named Corona Borealis – or the “Northern Crown.” Just northwest of its brightest star is a huge concentration of over 400 galaxies that reside over a billion light-years away from us. This area is so small from our point of view that we could cover it with our thumbnails held at arm’s length!

Tuesday, June 19 – Just when you thought watching the sky couldn’t get any better… It does. Tonight the mighty Saturn will be less than one half degree from the Moon – and will present a splendid occultation opportunity for many observers. If you don’t have a chance to see this one, perhaps you will fare better with Regulus, which is also less than one half degree from the Moon and presents an occultation opportunity. Be sure to check IOTA for precise information. Even if an event doesn’t happen for your location, this will be a sight you won’t want to miss!

While you’re watching the event, be sure to take the time to view the lunar surface for a couple of telescopic challenges that are easy to catch – all you have to know is Mare Crisium! On the southeastern shoreline is a peninsula which reaches into Crisium’s dark basin. This is Promontorium Agarum. On the western shore, bright Proclus lights the banks, but look into the interior for the two dark pock marks of Pierce to the north and Picard to the south. Be sure to mark them on your notes!

When you’re finished, point your binoculars or telescopes back towards Corona Borealis and about three fingerwidths northwest of Alpha for variable star R (Ra 15. 48.6 Dec +28 09). This star is a total enigma. Discovered in 1795, most of the time R carries a magnitude near 6, but can drop to magnitude 14 in a matter of weeks – only to unexpectedly brighten again! It is believed that R emits a carbon cloud which blocks its light. When studied at minima, the light curve resembles a “reverse nova,” and has a peculiar spectrum. It is very possible this ancient Population II star has used all of its hydrogen fuel and is now fusing helium to carbon. It’s so odd that science can’t even directly determine its distance!

Wednesday, June 20 – With no Moon to contend with in the predawn hours, we welcome the “shooting stars” as we pass through another portion of the Ophiuchid meteor stream. The radiant for this pass will be nearer Sagittarius and the fall rate varies from 8 to 20, but it can sometimes produce unexpectedly more.

Tonight we’ll return again to the lunar surface first to pick off another study object on our list – Messier and Messier A.

Located in Mare Fecunditatis about 1/3 its width from west to east, this pair of twin craters will be difficult in binoculars, but not hard for even a small telescope and intermediate power. Indeed named for famed French astronomer, Charles Messier, the easternmost crater is somewhat oval in shape with dimensions of 9 by 11 kilometers. At high power, Messier A to the west appears to have overlapped a smaller crater during its formation and it is slightly larger at 11 by 13 kilometers. Although it is not on the challenge list, you’ll find another point of interest to the northwest. Rima Messier is a long surface crack which runs diagonally across Mare Fecunditatis’ northwestern flank and reaches a length of 100 kilometers.

For variable star fans, let’s return again to Corona Borealis and focus our attention on S – located just west of Theta – the westernmost star in the constellation’s arc formation. At magnitude 5.3, this long-term variable takes almost a year to go through its changes; usually far outshining the 7th magnitude star to its northeast – but will drop to a barely visible magnitude 14 at minimum. Compare it to the eclipsing binary U Coronae Borealis about a degree northwest. In slightly over three days this Algol-type will range by a full magnitude as its companions draw together.

Thursday, June 21 – Summer Solstice occurs today at 12:26 UT. So what exactly is it? Solstice is nothing more than an astronomical term for the moment when one hemisphere of the Earth is tilted the most toward the Sun. Today, the sun is about 24 degrees above the celestial equator – its highest point of the year. The day of summer solstice also has the longest period of daylight…and the shortest of night; this occurs around 6 months from now for the Southern Hemisphere.

If you haven’t had the chance to pick up crater Posidonius for your lunar studies, tonight would be a great time to power up and really study this ancient mountain-walled plain. Standing on the northeast shore of Mare Serenitatis near the terminator, this melted-down and lava-filled area looks very flat, with gently stepped walls. Still, it stretches an admirable 95 kilometers in diameter and drops to a depth of 2300 meters at the floor. During this sunrise phase, it is possible to spot some of the huge systems of rimae which line its floor, even in binoculars. This extended system of cracks gives mute testimony to Posidonius’ volcanic history, and several strikes – such as the A crater near the center – help this crater to show its age well!

Friday, June 22 – Today celebrates the founding of the Royal Greenwich Observatory in 1675. That’s 332 years of astronomy! Also on this date in history, in 1978, James Christy of the US Naval Observatory in Flagstaff Arizona discovered Pluto’s satellite Charon.

While observing Pluto is quite possible with a mid-sized (8″) telescope, careful work is needed to separate and identify it from field stars. Just a few days ago, Pluto reached opposition, meaning it is viewable all night. Since it will take several nights of observation for confirmation, right now would be an excellent time to begin your Pluto quest. With a little research you’ll find plenty of on-line locator charts to help guide you on your way!

If you observe the Moon tonight, be sure to note both Gemma Frisius and Maurolycus on your lunar challenge list. While at Gemma Frisius, let’s look for a little more “off the beaten path” crater about halfway towards Catharina. Under tonight’s lighting at low power, you’ll see it first as a sunken oval – but power up and let’s explore Sacrobosco.

Named for the English mathematician “John of Holywood” (Johannes Sacrobuschus), this class III crater spans 98 kilometers and drops down to a floor level of 2800 meters – making those crater walls about as high as the West Ridge of Mt. Everest. On its troubled floor you will see the evidence of three far newer impacts: Crater C to the north which spans 13 kilometers and drops down 2630 meters; Crater A to the west which is 18 kilometers in diameter and 1830 meters deep; and Crater B to the east at 15 kilometers wide and 1210 meters deep. While these strikes are fascinating…look again. Sacrobosco itself is imprinted over the top of a far older crater!

Saturday, June 23 – Our lunar challenge feature for this evening is prominent enough to be spotted in binoculars, but well worth the time to power up with the telescope and explore. Starting with the recognizable slash of the Alpine Valley, follow the mountain trail south to the double strike of crater Cassini.

Named for Giovanni Cassini, this smashing old Class V crater rises above the lunar topography by 1067 meters, making its shallow walls alone as tall as the Catskill Mountains. It covers about 57 kilometers of lunar landscape in its rough diameter and the crater floor is 1240 kilometers below the surface. At one time Cassini may very well have had a central peak, but something quite took care of that when it formed Cassini A. This double-stepped feature is 57 kilometers in diameter and drops down an additional 2830 meters. While both Cassini and Cassini A are lunar club challenges, look carefully for yet another interior crater. Small crater B is often referred to as the “Washbowl” for its almost perfect concave structure.

While we’re out, let’s have a look at Delta Serpens. To the eye and binoculars, 4th magnitude Delta is a widely separated visual double star… But power up in the telescope to have a look at a wonderfully difficult binary. Divided by no more than 4 arc seconds, 210 light-year distant Delta and its 5th magnitude companion could be as old as 800 million years and on the verge of becoming evolved giants. Separated by about 9 times the distance of Pluto from our Sun, the white primary is a Delta Scuti-type variable which changes subtly in less than four hours. Although it takes the pair 3200 years to orbit each other, you’ll find Delta Serpens to be an excellent challenge for your optics.

Sunday, June 24 – On this day in 1881, Sir William Huggins made the first photographic spectrum of a comet (1881 III) and discovered cyanogen (CN) emission at violet wavelengths. Unfortunately, his discovery caused public panic around 29 years later when Earth passed through the tail of Halley’s Comet. What a shame the public didn’t realize that cyanogens are also released organically! More than fearing what is in a comet’s tail, they should have been thinking about what might happen should a comet strike. Tonight look at the wasted Southern Highland area of the Moon with new eyes… Many of these craters you see were caused by impacts – some as large as the nucleus of Halley itself.

Now let’s turn binoculars or telescopes towards magnitude 2.7 Alpha Librae – the second brightest star in the celestial “Scales.” Its proper name is Zuben El Genubi, and even as “Star Wars” as that sounds, the “Southern Claw” is actually quite close to home at a distance of only 65 light-years.

No matter what size optics you are using, you’ll easily see Alpha’s 5th magnitude companion widely spaced and sharing the same proper motion. Alpha itself is a spectroscopic binary which was verified during an occultation event, and its inseparable companion is only a half magnitude dimmer according to the light curves. Enjoy this easy pair tonight!

Monday, June 11 – Tonight we make the jump to Serpens Caput, which is in itself a challenge to recognize with the unaided eye. Using bright Spica as a guide, look about a handspan northeast for two of the brightest stars in the constellation – Alpha, and Lambda to its northeast. Using binoculars, locate a pairing with Delta to the north-northwest and Mu to the south. Now return to Alpha and hop a little less than a fistwidth to the southwest where you will encounter double star 5 Serpens and the mighty M5.

While Gottfried Kirch and his wife Maria were watching a comet on May 5, 1702, they stumbled across a huge, bright object that they considered a “nebulous star.” Forty-two years later, it was found again by Messier who labeled it as M5 and described it as a round nebula which didn’t contain any stars. But, thank heaven for William Herschel! Some 27 years later he counted up to 200 resolvable stars in this globular cluster and reported “the middle is so compressed that it is impossible to distinguish the components.”

Even in today’s binoculars, M5 shows a grainy texture that begins resolution to even the smallest of telescopes and invites larger ones to an explosion of stellar population. Slightly elliptical in appearance, M5 is believed to be one of the oldest globular clusters with a calculated age of 13 billion years, and it contains 105 known variable stars – as well as a dwarf nova. At a distance of 24,500 light-years and stretching across 165 light-years of space, this magnificent object so dominates its territory that it would gather in any stars straying within 400 light-years of its tidal influence!

Mid-to-larger telescopes will begin such awesome resolution on M5’s many chains and its bright core region that it will be a cluster you will visit again and again over the years. No matter what size binoculars or telescope you use, this 5.6 magnitude class V globular cluster is one of the five brightest of all!

Tuesday, June 12 – As with all astronomical projects, there are sometimes difficult ones needed to complete certain study fields – such as challenging globular clusters. Tonight we’ll take a look at one such cluster needed to complete your list and you’ll find it by using M5 as a guide.

Palomar 5 is by no stretch of the imagination easy. For those using GoTo systems and large telescopes, aiming is easy… But for star hoppers a bit of instruction goes a long way. Starting at M5 drop south for the double 5 Serpens and again south and slightly west for another, fainter double. Don’t confuse it with 6 Serpens to the east. About half a degree west you’ll encounter an 8th magnitude star with 7th magnitude 4 Serpens a half degree south. Continue south another half degree where you will discover a triangle of 9th magnitude stars with a southern one at the apex. This is home to Palomar 5 (RA 15 16 05.30 Dec -00 06 41.0).

Discovered by Walter Baade in 1950, this 11.7 magnitude, Class XII globular is anything but easy. At first it was believed to be a dwarf elliptical and possibly a member of our own Local Group of galaxies due to some resolution. Later studies showed that Palomar 5 was indeed a globular cluster – but one that was being ripped apart by the tidal forces of the Milky Way.

75,000 light-years away from us and 60,000 light-years from the galactic center, Palomar 5’s members are escaping and leaving trails that span 13,000 light-years…a process which may have been happening for several billion years. Although it is of low surface brightness, even telescopes as small as 6″ can distinguish just a few individual members northwest of the 9th magnitude marker star – but even telescopes as large as 31″ fail to show much more than a faint sheen (under excellent conditions) with a handful of resolvable stars.

Even though it may be one of the toughest you’ll ever tackle, be sure to take the time to make a quick sketch of the region to complete your studies. Good luck!

Wednesday, June 13 – If you’re up before dawn this morning, be sure to check out the slender crescent Moon just before dawn. The “Old Moon in The New Moon’s Arms” is worth getting up for!

Today in 1983, Pioneer 10 becomes the first manmade object to leave the solar system. What wonders would it see? Are there other galaxies out there like our own? Will there be life like ours? While we can’t see through Pioneer’s “eyes,” tonight let’s use our own as we quest for a look in the mirror…

Our object will be Herschel II.76 – also known as NGC 5970. Begin by identifying Beta and Delta Serpens Caput and look for finderscope Chi between them. Less than a degree southwest you will see a similar magnitude double star. Hop about 1/3 degree northwest and you will find your galaxy mark just a fraction southwest of a 7th magnitude star (RA 15 38 30.12 Dec -12 11 10.9).

NGC 5970 is not particularly easy for smaller scopes even near 11th magnitude because of low surface brightness, but it could be a distant twin of our own galaxy, so similar is it to the Milky Way in structure. At 105 million light-years away, it is no great surprise that we see it as faint – for its light left around the time the dinosaurs ruled the Earth. Stretching across 85,000 light-years of space, this grand spiral has been extensively studied in its nucleus region, obscuring dust regions, and stellar population. And – like us – it is also part of its own local group.

While smaller telescopes will make out a slight elongated mist, in mid-to-large aperture NGC 5970 will appear oval shaped with a bright core and evidence of a central bar. While the edges of the galaxy seem well defined, look closely at the narrower ends where material seems more wispy. While averted in this fashion, the nucleus will sometimes take on a stellar appearance – yet lose this property with direct vision. Be sure to mark your Herschel notes on this one!

Thursday, June 14 – As the new hours of the day begin and you wait on dawn, keep watch for the peak of the Ophiuchids meteor shower with the radiant near Scorpius. The fall rate is poor with only 3 per hour, but fast moving bolides are common. This meteor stream will last for 25 days.

Tonight, while we have plenty of dark skies to go around, let’s go south in Libra and have a look at the galaxy pairing NGC 5903 and NGC 5898. You’ll find them about three degrees northeast of Sigma, and just north of a pair of 7th magnitude stars.

While northernmost NGC 5903 seems to be nothing more than a faint elliptical with a brighter concentration towards the center and an almost identical elliptical – NGC 5898 – to the southwest, you’re probably asking yourself… Why the big deal over two small ellipticals? First off, NGC 5903 is Herschel III.139 and NGC 5898 is Herschel III.138… two more to add to your studies. And second? The Very Large Array has studied this galaxy pair in the spectral lines of neutral hydrogen. The brighter of the pair, NGC 5898, shows evidence of ionized gas which has been collected from outside its galactic realm – while NGC 5903 seems to be running streamers of material towards it. A double-galaxy, double-accretion event!

But there’s more…

Look to the southeast and you’ll double your pleasure and double your fun as you discover two double stars instead of just one! Sometimes we overlook field stars for reasons of study – but don’t do it tonight. Even mid-sized telescopes can easily reveal this twin pair of galaxies sharing “their stuff,” as well as a pair of double stars in the same low power field of view. (Psst… slim and dim MCG 043607 and quasar 1514-241 are also here!) Ain’t it grand?

Friday, June 15 – Tonight is officially New Moon. Before you hunt down the faint fuzzies and spend the rest of the night drooling on the Milky Way, let’s go globular and hunt up two very nice studies worthy of your time. Starting at Alpha Librae, head five degrees southeast for Tau and yet another degree southeast for the splendid field of NGC 5897 (RA 15 17 24.40 Dec -21 00 36.4).

This class XI globular might appear very faint to binoculars, but it definitely makes up for it in size and beauty of field. It was first viewed by William Herschel on April 25, 1784 and logged as H VI.8 – but with a less than perfect notation of position. When he reviewed it again on March 10, 1785 he logged it correctly and relabeled it as H VI.19. At a distance of a little more than 40,000 light-years away, this 8.5 magnitude globular will show some details to the larger telescope, but remain unresolved to smaller ones. As a halo globular cluster, NGC 5897 certainly shows signs of being disrupted and has a number of blue stragglers as well as four newly discovered variables of the RR Lyrae type.

Now let’s return to Alpha Librae and head about a fistwidth south across the border into Hydra and two degrees east of star 57 for NGC 5694 – also in an attractive field (RA 14 39 36.52 Dec -26 32 18.0).

Also discovered by Herschel, and cataloged as H II.196, this class VII cluster is far too faint for binoculars at magnitude 10, and barely within reach of smaller scopes. As one of the most remote globular clusters in our galaxy, few telescopes can hope to resolve this more than 113,000 light-year distant ball of stars whose brightest is magnitude 16.5 – and it also possesses no variables. Traveling at 190 kilometers per second, metal-poor NGC 5694 will not have the same fate as NGC 5897… For this is a globular cluster that is not being pulled apart by our galaxy – but escaping it!

Saturday, June 16 – No matter if you stayed up late chasing deep sky, or got up early, right now is the time to catch the peak of the June Lyrids meteor shower. Although it’s not the most outstanding of displays, no Moon will make it one of the best prospects of the year for those wishing to log their meteor observations. Look for the radiant near bright Vega – you may see up to 15 faint blue meteors per hour from this branch of the May Lyrid meteor stream.

Today in 1963, Valentina Tereshkova, aboard the Soviet Vostok 6, became the first woman ever to go into space. Her solo flight is still unique. Twenty years later, on the 18th, Sally Ride became the first American woman in orbit, aboard the Space Shuttle.

If you have an open western horizon, a true challenge tonight will be to spot Mercury a little more than 5 degrees south of a very tender and very young crescent Moon. If you miss it, don’t be dismayed for the coming days will bring up some of the most delightful celestial scenery of all!

For observers of all skill levels and equipment, it’s simply time to stop and have a look at a seasonal favorite which is now nearly overhead – M13. You’ll find this massive globular cluster quite easy to locate on the western side of the Hercules “keystone” about 1/3 the way between the northern and southern stars – Eta and Zeta.

At a little brighter than magnitude 6, this 25,100 light-year distant globular cluster can be seen unaided from a dark sky location. First noted by Edmond Halley in 1714, the “Great Hercules Cluster” was cataloged by Messier on June 1, 1764. Filled with hundreds of thousands of stars, yet only one young blue star, M13 could be as much as 14 billion years old.

Thirty-three years ago, the Great Hercules Cluster was chosen by the Arecibo Observatory as the target for the first radio message delivered into space, yet it will be a message that won’t be received for over 25 centuries. Look at it with wonder tonight… For the light that left as you are viewing it tonight did so at a time when the Earth was coming out of the Ice Age. Our early ancestors were living in caves and learning to use rudimentary tools. How evolved would our civilization be if we ever received an answer to our call?!

Sunday, June 17 – Be sure to be outside as the Sun sets this evening to catch the very beginnings of the Moon as it joins bright star Pollux. This conjunction puts one of the Gemini “twins” less than two fingerwidths north. For the next two evenings, SkyWatchers will have some wonderful opportunities to view some of the best conjunctions of the year!

As the sky darkens, let’s discover the wonderful world of low power. Start by re-locating the magnificent M13 and move about 3 degrees northwest. What you will find is a splendid loose open cluster of stars known as Dolidze/Dzimselejsvili (DoDz) 5 – and it looks much like a miniature of the constellation of Hercules. Just slightly more than 4 degrees to its east and just about a degree south of Eta Hercules is DoDz 6, which contains a perfect diamond pattern and an asterism of brighter stars which resembles the constellation of Sagitta.

Now we’re going to move across the constellation of Hercules towards Lyra. East of the “keystone” you will see a tight configuration of three stars – Omicron, Nu and Xi. About the same distance that separates these stars to the northeast you will find DoDz 9. Using minimal magnification, you’ll see a pretty open cluster of around two dozen mixed magnitude stars that are quite attractive. Now look again at the “keystone” and identify Lambda and Delta to its south. About midway between them and slightly to the southeast you will discover the stellar field of DoDz 8. The last is easy – all you need to do is know the beautiful red/green double, Ras Algethi (Alpha). Move about 1 degree to the northwest to discover the star-studded open cluster DoDz 7. These great open clusters are very much off the beaten path and will add a new dimension to your large binocular or low power telescoping experiences.

Monday, June 4 – Tonight we’ll use Rho Virginis as a stepping stone to more galaxies. Get on your mark and move one and a half degrees north for M59…

First discovered in 1779 by J. G. Koehler while studying a comet, this 11th magnitude elliptical galaxy was observed and labeled by Messier who was just a bit behind him. Much denser than our own galaxy, M59 is only about one-fourth the size of the Milky Way. In a smaller telescope, it will appear as a faint oval, while larger telescopes will make out a more concentrated core region.

Now shift one half degree east for brighter and larger M60. Also caught first by Koehler on the same night as M59, it was “discovered” a day later by yet another astronomer who had missed M59! It took Charles Messier another four days until this 10th magnitude galaxy interfered with his comet studies and was cataloged.

At around 60 million light-years away, M59 is one of the largest ellipticals known and has five times more mass than our galaxy. As a study object of the Hubble Telescope, this giant has shown a concentrated core with over 2 billion solar masses. Photographed and studied by large terrestrial telescopes, M59 may contain as many as 5100 globular clusters in its halo.

While our backyard equipment is essentially revealing M59’s core, there is a curiosity here. It shares “space” with spiral galaxy NGC 4647. Telescopes of even modest aperture will pick up the nucleus and faint structure of this small face-on galaxy. Harlow Shapely found the pair odd because – while they are relatively close in astronomical terms – they are very different in age and development. Halton Arp also studied this combination of an elliptical galaxy affecting a spiral and cataloged it as “Peculiar Galaxy 116.” Be sure to mark your notes!

Tuesday, June 5 – Tonight we’ll go back to Rho once again and about a fingerwidth northwest for yet another bright galaxy – M58 – a spiral galaxy actually discovered by Messier in 1779!

As one of the brightest galaxies in the Virgo cluster, M58 is one of only four that have barred structure. It was cataloged by Lord Rosse as a spiral in 1850. In binoculars, it will look much like our previously studied ellipticals, but a small telescope under good conditions will pick up the bright nucleus and a faint halo of structure – while larger ones will see the central concentration of the bar across the core. Chalk up another Messier study for both binoculars and telescopes and let’s get on to something really cool!

Around a half degree southwest are NGC 4567 and NGC 4569. L. S. Copeland dubbed them the “Siamese Twins,” but this galaxy pair is also considered part of the Virgo cluster. While seen from our viewpoint as touching galaxies, no evidence exists of tidal filaments or distortions in structure, making them a line of sight phenomenon and not interacting members. While that might take little of the excitement away from the “Twins,” a supernova event has been spotted in NGC 4569 as recently as 2004.

While the duo is visible in smaller scopes as two, with soft twin nuclei, intermediate and larger scopes will see an almost V-shaped or heart-shaped pattern where the structures overlap. If you’re doing double galaxy studies, this is a fine, bright one! If you see a faint galaxy in the field as well, be sure to add NGC 4564 to your notes.

For all you Stargazers, keep watch for the Scorpid meteor shower. Its radiant will be near the constellation of Ophiuchus, and the average fall rate will be about 20 per hour with some fireballs.

Wednesday, June 6 – So far we’ve studied many Herschel objects in disguise as Messier catalog items – but we haven’t really focused on some mighty fine galaxies that are within the power of the intermediate to large telescope. Tonight let’s take a serious skywalk as we head to 6 Comae and drop two degrees south.

At magnitude 10.9, Herschel catalog object H I.35 is also known by its New General Catalog number of 4216. This splendid edge-on galaxy has a bright nucleus and will walk right out in larger telescopes with no aversion required. But, the most fascinating part about studying anything in the Virgo cluster is about to be revealed.

While studying structure in NGC 4216, averted vision picks up magnitude 12 NGC 4206 to the south. This is also a Herschel object – H II.135. While it is smaller and fainter, the nucleus will be the first thing to catch your attention – and then you’ll notice it is also an edge-on galaxy! As if this weren’t distracting enough, while re-centering NGC 4216, sometimes the movement is just enough to allow the viewer to catch yet another edge-on galaxy to the north – NGC 4222. At magnitude 14, you can only expect to be able to see it in larger scopes, but what a treat this trio is!

Is there a connection between certain types of galaxy structures within the Virgo cluster? Science certainly seems to think so. While low metallicity studies involving these galaxies are going on, research into evolution of galaxy clusters themselves continue to make new strides forward in our understanding of the universe.

Capture them tonight!

Thursday, June 7 – If you’re up before dawn the next two days or out just after sunset, enjoy the peak of the June Arietid meteors – the year’s strongest daylight shower – with up to 30 visible per hour.

If you’d like to try your ear at radio astronomy with the offspring of sungrazing asteroid Icarus, tune an FM radio to the lowest frequency not receiving a clear signal. An outdoor antenna pointed at the zenith increases your chances, but even a car radio can pick up strong bursts! Simply turn up the static and listen. Those hums, whistles, beeps, bongs, and occasional snatches of signals are our own radio signals being reflected off the meteor’s ion trail!

Tonight let’s study a radio-source galaxy so bright it can be seen in binoculars – 8.6 magnitude M87, about two fingerwidths northwest of Rho Virginis.

This giant elliptical was discovered by Charles Messier in 1781 and cataloged as M87. Spanning 120,000 light-years, it’s an incredibly luminous galaxy containing far more mass and stars than the Milky Way – gravitationally distorting its four dwarf satellites galaxies. M87 is known to contain in excess of several thousand globular clusters – up to 150,000 – and far more than our own 200.

In 1918, H. D. Curtis of Lick Observatory discovered something else – M87 has a jet of gaseous material extending from its core and pushing out several thousand light-years into space. This highly perturbed jet exhibits the same polarization as synchrotron radiation – a property of neutron stars. Containing a series of small knots and clouds as observed by Halton Arp at Palomar in 1977, he also discovered a second jet in 1966 erupting in the opposite direction. Thanks to these two properties, M87 made Arp’s “Catalog of Peculiar Galaxies” as number 152.

In 1954 Walter Baade and R. Minkowski identified M87 with radio source Virgo A, discovering a weaker halo in 1956. Its position over an x-ray cloud extending through the Virgo cluster make M87 a source of an incredible amount of x-rays. Because of its many strange properties, M87 remains a target of scientific investigation. The Hubble has shown a violent nucleus surrounded by a fast rotating accretion disc, whose gaseous make-up may be part of a huge system of interstellar matter. As of today, only one supernova event has been recorded – yet M87 remains one of the most active and highly prized study galaxies of all. Capture it tonight!

Friday, June 8 – Born on this date in 1625 was Giovanni Cassini – the most notable observer following Galileo. As head of the Paris Observatory for many years, he was the first to observe seasonal changes on Mars and measure its parallax (and so, its distance). This set the scale of the solar system for the first time. Cassini was the first to describe Jovian features, and studied the Galilean moons’ orbits. He also discovered four moons of Saturn, but he is best remembered for being the first to see the namesake division between the A and B rings.

Tonight let’s honor Cassini by taking a look at both planets – beginning with the westering Saturn. To the unaided eye, this creamy-yellow “star” outshines most stars in the region and holds competition with Regulus in Leo. To binoculars, it reveals itself as a planet – one with ears! While great detail cannot be seen, even the slightest optical aid makes it a joy.
To the small telescope, Saturn’s ring system becomes very clear, and bright Titan can easily be seen. To the mid-sized telescope, the “Lord of the Rings” easily shows the Cassini division as well as other small details and reveals the many smaller moons that dance along the ring edge. For the large telescope, Saturn continues to be one of the most fascinating of planets. Several ring divisions are easily apparent and subtle shading details on the planet’s surface are easily discerned. Titan shines very brightly and under good conditions will display a certain amount of limb darkening, making it perceivable as an orb. Tethys, Rhea and Dionne are easily visible, and the dimensionality of Saturn revealed through shadow-play is incredible.

To the east, Jupiter is rising… But give it some time to clear the atmospheric distortion! By far brighter than neighboring stars to the unaided eye, giant Jupiter will move slowly along the ecliptic plane over the course of the evening. To smaller binoculars it is easily observed as an orb with two grey bands across the middle. To larger binoculars, the equatorial belts become much clearer and the four Galilean moons are easily seen with steady hands. To the small telescope, no planet offers greater details. Even at very low magnifying power, the north, south and central equatorial zones are easily observable and all four moons are clear and steady.

To the mid-sized telescope, far greater details begin to appear – such as temperate belts on the planet’s surface and the soft appearance of the Great Red Spot. Finer details are visible during steady seeing, and small things like being able to see which satellite is closer to – or further away from – our vantage point become very easy. Simple things, like watching a moon transit the surface and the resulting shadow on the planet are much easier. With a large telescope, Jupiter depends more on seeing conditions for details. While more aperture allows finer views – conditions are everything when it comes to the Mighty Jove!

Saturday, June 9 – Today is the birthday of Johann Gottfried Galle. Born in Germany in 1812, Galle was the first observer to locate Neptune. He is also known for being Encke’s assistant – and he’s one of the few astronomers ever to have observed Halley’s Comet twice. Unfortunately, he died two months after the comet passed perihelion in 1910, but at a ripe old age of 98! I wonder if he knew Mark Twain?

For unaided observers, be sure to check out brilliant Venus as it reaches greatest elongation just after sunset!

Tonight while we’re out, let’s have a look at a Virgo galaxy bright enough for smaller instruments and detailed enough to delight larger scopes. Starting at Delta Virginis, move about a fistwidth to the west where you will see two fainter stars, 16 (south) and 17 (north) Virginis. You’ll find M61 located about one-half degree south of the yellow double star 17.

Its discovery was credited to Barnabus Oriani during that fateful year of 1779 when Messier was so avid about chasing a comet that he mistook it for one. While Charles had seen it on the same night, it took him two days to figure out it wasn’t moving and four more before he cataloged it. Fortunately, 7 years later Mr. Herschel assigned it his own number of H I.139, even though he wasn’t fond of assigning his own number to Messier catalog objects.

At near 10th magnitude, this spiral galaxy will show a slightly elongated form and brighter core area to small telescopes, and really come to life in larger ones. Close to our own Milky Way galaxy in size, this larger member of the Virgo cluster has great spiral arm structure that displays both knots and dark dustlanes – as well as a beautifully developed nucleus region. M61 has also been host to four supernova events between 1926 and 1999 – all of which have been well within range of amateur telescopes.

For an added Herschel treat tonight for larger scopes, hop back to star 17 and head about one half degree due west for near galactic pair NGC 4281 (H II.573) and NGC 4273 (H II.569). Here is a study of two galaxies similar in magnitude (12) and size – but of different structure. Northeastern NGC 4281 is an elliptical, and by virtue of its central concentration will appear slightly larger and brighter – while southwestern NGC 4273 is an irregular spiral which will appear brighter in the middle but more elongated and faded along its frontiers. Sharp-eyed observers may also note fainter (13th magnitude) NGC 4270 north of this pairing.

Sunday, June 10 – Although no one likes to get up early, this morning will be a great time to catch the close pairing of Mars and the waning Moon!

While I’m sure that unaided eye viewers and binocular users are tired of the galaxy hunt, be sure to take the time to look at many old favorites that are now in view. To the eye, one of the most splendid signs of the changing seasons is the Ursa Major Moving Group which sits above Polaris for northern hemisphere observers. For the southern hemisphere, the return of Crux serves the same purpose.

Old favorites have now begun to appear again, such as Hercules, Cygnus and Scorpius… and with them a wealth of starry clusters and nebulae that will soon come into view as the night deepens and the hour grows late. Before we leave Virgo for the year, there is one last object that is seldom explored and such a worthy target that we must visit it before we go. Its name is NGC 5634 and you’ll find it halfway between Iota and Mu Virginis (RA 14 29.37 Dec -05 58.35)…First discovered by Sir William Herschel on March 5, 1785 and cataloged as H I.70, this magnitude 9.5 small globular cluster isn’t for everyone, but thanks to an 11th magnitude line-of-sight star on its eastern edge, it sure is interesting. At class IV, it’s more concentrated than many globular clusters, although its 19th magnitude members make it near impossible to resolve with backyard equipment.

Located a bit more than 82,000 light-years from our solar system and about 69,000 light-years from the galactic center, you’ll truly enjoy this globular for the randomly scattered stellar field which accompanies it. In the finderscope, an 8th magnitude star will lead the way – not truly a member of the cluster, but one that lies between us. Capturable in scopes as small as 4.5″, look for a concentrated central area surrounded by a haze of stellar members – a huge number of which are recently discovered variables. While you look at this globular, keep this in mind…

Based on observations with the Italian Telescopio Nazionale Galileo, it is now surmised that the NGC 5634 globular cluster has the same position and radial velocity as does the Sagittarius dwarf spheroidal galaxy. Because of the dwarf galaxy’s metal-poor population of stars, it is believed that NGC 5634 may have once been part of the dwarf galaxy – and been pulled away by our own tidal field to become part of the Sagittarius stream!

Monday, May 28 – On this day in 1959, the first primates made it to space. Abel (a rhesus monkey) and Baker (a squirrel monkey) lifted off in the nose cone of an Army Jupiter missile and were carried to sub-orbital flight. Recovered unharmed, Abel died just three days later from anesthesia during an electrode removal, but Baker lived on to a ripe old age of 27.

Tonight let’s monkey around the stars as we head towards the Moon and see Spica, just a little more than a degree to the north. Although at first glance tonight crater Copernicus will try to steal the scene, head further south to capture another lunar club challenge – Bullialdus. Even binoculars can make out this crater with ease near the center of Mare Nubium. If you’re scoping – power up – this one is fun! Very similar to Copernicus, note Bullialdus’ thick, terraced walls and central peak. If you examine the area around it carefully, you can note it is a much newer crater than shallow Lubiniezsky to its north and almost non-existent Kies to the south. On Bullialdus’ southern flank, it’s easy to make out its A and B craters, as well as the interesting little Koenig to the southwest.

Now let’s head about four fingerwidths northwest of Beta Virginis for another unusual star – Omega. Classed as an M-type red giant, this 480 light-year distant beauty is also an irregular variable which fluxes by about half a magnitude. Although you won’t notice much change in this 5th magnitude star, it has a very pretty red coloration and is worth the time to view.

Tuesday, May 29 – Today in 1919, a total eclipse of the Sun occurred and stellar measurements taken along the limb agreed with predictions based on Einstein’s General Relativity theory – the first such confirmation. Although we call it gravity, spacetime curvature deflects the light of stars near the limb, causing their apparent positions to differ slightly. Unlike today’s astronomy, at that time you could only observe stars near the Sun’s limb (within less than an arc second) during an eclipse. It’s interesting to note that even Newton had his own theories on light and gravitation which predicted some deflection!

Tonight would be a wonderful opportunity for Moongazers to return to the surface and have a look at the peaceful Sinus Iridum area. If you’ve been clouded out before, be sure to have a look for telescopic lunar club challenges – Promontoriums Heraclides and LaPlace.

If you’re up for a bit more of a challenge, then let’s head about 59 light-years away in Virgo for star 70. You’ll find it located about 6 degrees northeast of Eta and right in the corner of the Coma, Boötes, and Virgo border. So what’s so special about this G-type, very normal-looking 5th magnitude star?

It’s a star that has a planet.

Long believed to be a spectroscopic binary because of its 117 day shifts in color, closer inspection has revealed that 70 Virginis actually has a companion planet. Roughly 7 times larger than Jupiter and orbiting no further away than Mercury from its cooler-than-Sol parent star, 70 Virginis B just might well be a planet cool enough to support water in its liquid form.

How “cool” is that? Try about 85 degrees Celsius…

Wednesday, May 30 – Tonight let’s have a look at a very bright and changeable lunar feature that is often over-looked. Starting with the great grey oval of Grimaldi, let your eyes slide along the terminator towards the south until you encounter the bright crater Byrgius.

Named for Joost Burgi, who made a sextant for Tycho Brahe, this “seen on the curve” crater is really quite large with a diameter of 87 kilometers. Perhaps one of the most interesting features of all is high albedo Byrgius A, which sits along its east wall line and produces a wonderfully bright ray system. While it is not noted as a lunar club challenge, it’s a great crater to help add to your knowledge of selenography!

Now let’s add to our double star list as we hunt down Zeta Boötes located about 7 degrees southeast of Arcturus. This is a delightful multiple star system for even small telescopes.

Thursday, May 31 – While tonight the Moon will appear about as full as it gets to some observers, the date won’t be “official” until tomorrow. While the glare will make it difficult to do many things, we can still have a look at other bright objects! Let’s start tonight by going just north of Zeta Boötes for Pi. With a wider separation, this pair of whites will easily resolve to the smaller telescope.

Now skip up northeast about a degree for Omicron Boötes. While this is not a multiple system, it makes for a nice visual pairing for a binocular challenge. For telescopes, the southeastern star holds interest as a small asterism.

Continue northeast another two degrees to discover Xi Boötes. This one is a genuine multiple star system with magnitude 5 and 7 companions. Not only will you enjoy this G-type sun for its duplicity, but for the fine field of stars in which it resides!

Friday, June 1 – Tonight the Moon is full. Often referred to as the Full Strawberry Moon, this name was a constant to every Algonquin tribe in North America. But, our friends in Europe referred to it as the Rose Moon. The North American version came about because the short season for harvesting strawberries comes each year during the month of June – so the full Moon that occurs during that month was named for this tasty red fruit!

Tonight before it rises and the light commands the sky, let’s have a look at a tasty red star – R Hydrae. You’ll find it about a fistwidth south of Spica or about a fingerwidth west of Gamma Hydrae.

R was the third long term variable star to be discovered and it is credited to Maraldi in 1704. While it had been observed by Hevelius some 42 years earlier, it was not recognized immediately because its changes happen over more than a year. At maximum, R reaches near 4th magnitude – but drops well below human eye perception to magnitude 10. During Maraldi’s and Hevelius’ time, this incredible star took over 500 days to change, but it has speeded up to around 390 days in the present century.

Why such a wide range? Science isn’t really sure. R Hydrae is a pulsing M-type giant whose evolution may be progressing more rapidly than expected due to changes in structure. What we do know is that it is around 325 light-years away and is approaching us at around 10 kilometers per second.

In the telescope, R will have a pronounced red coloration which deepens near minima. Nearby is 12th magnitude visual companion star Ho 381, which was first measured for position angle and distance in 1891. Since that time no changes in separation have been noted, which leads us to believe that the pair may be a true binary.

Saturday, June 2 – Before the Moon rises tonight, let’s return again to R Hydrae. While observing a variable star with either the unaided eye, binoculars, or a telescope can be very rewarding, it’s often quite difficult to catch changes in long-term variables, because there are times when the constellation is not visible. While R Hydrae is unique in color, let’s drop about half a degree to the southeast to visit another variable star – SS Hydrae.

SS is a quick change artist – the Algol-type. While you will need binoculars or a telescope to see this normally 7.7 magnitude star, at least its fluctuations are far more rapid, with a period of only 8.2 days. With R Hydrae we have a star that expands and contracts causing the changes in brightness – but SS is an eclipsing binary. While less than a half magnitude is not a noteworthy amount, you will notice a difference if you view it over a period of time. Be sure to note that this is actually a triple star system, for there is also a 13th magnitude companion star located 13″ from the primary. Watch if as often as possible and see if you can detect changes in the next few weeks!

When the Moon rises tonight, take a look at the northwestern limb about half the distance between Grimaldi and Sinus Iridum. Our search is for an “on the edge” crater known as Einstein. Use the prominent crater Kraft to help guide you to this extreme edge feature!

Sunday, June 3 – If you’re up early, why not keep a watch out for the peak of the Tau Herculids meteor shower? These are the offspring of comet Schwassman-Wachmann 3, which broke up in 2006. The radiant is near Corona Borealis and we’ll be in this stream for about a month. At best when the parent comet has passed perihelion, you’ll catch about 15 per hour maximum. Most are quite faint and the westering Moon will interfere, but sharp-eyed observers will enjoy it.

While we have a bit of time tonight to spare before the Moon rises, let’s try a visual double for the unaided eye – Eta Virginis. Can you distinguish between a 4th and 6th magnitude pair?

The brighter of the two is Zaniah (Eta), which through occultation had been discovered to be a triple star. In 2002, Zaniah became the first star imaged by combining multiple telescopes with the Navy Prototype Optical Interferometer. This was the first time the three were split. Two of them are so close that they orbit in less than half the distance between the Earth and Sun!

Binocular users should take a look at visual double Rho Virginis about a fistwidth west-southwest of Epsilon. This pair is far closer and will require an optical aid to separate. The brighter of this pair – Rho – is a white, main sequence dwarf with a secret… It’s a variable! Known as a Delta Scuti type, this odd star can vary slightly in magnitude in anywhere from 30 minutes to two and a half hours as it pulsates.

For mid-to-large telescopes, Rho offers just a little bit more. The visual companion star has a visual companion as well! Less than a half degree southwest of Rho is a small, faint spiral galaxy – NGC 4608 – at 12th magnitude, it’s hard to see because of Rho’s brightness…but it’s not alone. Look for a small, but curiously shaped galaxy labeled NGC 4596. Its resemblance to the planet Saturn makes it well worthwhile!

Monday, May 21 – In 1961, United States President John F. Kennedy launches the country on a journey to the Moon as he makes 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…”

Tonight let’s take our own journey to the Moon as we look at a beautiful series of craters – Fabricius, Metius and Rheita.

Bordered on the south by shallow Jannsen, lunar club challenge Fabricius is a 78 kilometer diameter crater highlighted by two small interior mountain ranges. To its northeast is Metius, which is slightly larger with a diameter of 88 kilometers. Look carefully at the two. Metius has much steeper walls, while Fabricius shows differing levels and heights. Metius’ smooth floor also contains a very prominent B crater on the inside of its southeast crater wall.

Further northeast is the lovely Rheita Valley which stretches almost 500 kilometers and appears more like a series of confluent craters than a fault line. 70 kilometer diameter crater Rheita is far younger than this formation because it intrudes upon it. Look for a bright point inside the crater which is its central peak.

While the Moon is still west, let’s have a look at telescopic star W Virginis located about three and a half degrees southwest of Zeta (RA 13 26 01.99 Dec -03 22 43.4). This 11,000 light-year distant Cepheid type variable is oddly enough a Population II star that lies outside the galactic plane. This expanding and contracting star goes through its changes in a little over 17 days and will vary between 8th and 9th magnitude. Although it is undeniably a Cepheid, it breaks the rules by being both out of place in the cosmic scheme and displaying abnormal spectral qualities!

Tuesday, May 22 – Tonight the Moon will be our companion. Now well risen above atmospheric disturbance, this would be a great time to have a look for several lunar club challenges that you might have missed.

Most prominent of all will be two craters to the north named Atlas and Hercules. The eastern-most Atlas was named for the mythical figure which bore the weight of the world on his shoulders, and the crater spans 87 kilometers and contains a vivid Y-shaped rima in the interior basin. Western Hercules is considerably smaller at 69 kilometers in diameter and shows a deep interior crater called G. Power up and look for the tiny E crater which marks the southern crater rim. North of both is another unusual feature which many observers miss. It is a much more eroded and far older crater which only shows a basic outline and is only known as Atlas E.

Since we’re here, let’s take a crater walk and see how many features we can identify. Good luck and clear skies!

(1) Mare Humboldtianum, (2) Endymion, (3) Atlas, (4) Hercules, (5) Chevalier, (6) Shuckburgh, (7) Hooke, (8) Cepheus, (9) Franklin, (10) Berzelius, (11) Maury, (12) Lacus Somniorum, (13) Daniel, (14) Grove, (15) Williams, (16) Mason, (17) Plana, (18) Burg, (19) Lacus Mortis, (20) Baily, (21) Atlas E, (22) Keldysh, (23) Mare Frigoris, (24) Democritus, (25) Gartner, (26) Schwabe, (27) Thales, (28) Strabo, (29) de la Rue, (30) Hayn.

Wednesday, May 23 – Tonight no two lunar features in the north will be more prominent than Aristoteles and Eudoxus. Viewable even in small binoculars, let’s take a closer look at larger Aristoteles to the north.

As a Class 1 crater, this ancient old beauty has some of the most massive walls of all lunar features. Named for the great philosopher, it stretches across 87 kilometers of lunar landscape and drops below the average surface to a depth of 366 meters – a height which is similar to Earth’s tallest waterfall, the Silver Cord Cascade. While it has a few scattered interior peaks, the crater floor remains almost unscarred. As a telescopic lunar club challenge, be sure to look for a much older crater that sits on Aristoteles eastern edge. Tiny Mitchell is extremely shallow by comparison and only spans 30 kilometers. Look carefully at the formation, for although Aristoteles overlaps Mitchell, the smaller crater is actually part of the vast system of ridges which supports the larger.

Now let’s have a look at Iota Virginis. While there is nothing particularly special about this spectral F type star, it does reside in a very interesting field for low power. Enjoy the colors!

Thursday, May 24 – While the Moon moves quietly towards Virgo, our first challenge for the evening will be a telescopic one on the lunar surface known as the Hadley Rille. Using our past knowledge of Mare Serenitatis, look for the break along its western shoreline that divides the Caucasus and Apennine mountain ranges. Just south of this break is the bright peak of Mons Hadley. You’ll find this area of highest interest for several reasons, so power up as much as possible.

Impressive Mons Hadley measures about 24 by 48 kilometers at its base and reaches up an incredible 4572 meters. If this mountain was indeed caused by volcanic activity on the lunar surface, this would make it comparable to some of the very highest volcanically caused peaks on Earth, such as Mount Shasta or Mount Rainer. To its south is the secondary peak Mons Hadley Delta – the home of the Apollo 15 landing site just a breath north of where it extends into the cove created by Palus Putredinus.

Along this ridgeline and smooth floor, look for a major fault line known as the Hadley Rille, winding its way across 120 kilometers of lunar surface. In places, the rille spans 1500 meters in width and drops to a depth of 300 meters below the surface. Believed to have been formed by volcanic activity some 3.3 billion years ago, we can see the impact that lower gravity has had on this type of formation, since earthly lava channels are less than 10 kilometers long and only around 100 meters wide.

During the Apollo 15 mission, Hadley Rille was visited at a point where it was only 1.6 kilometers wide – still a considerable distance as seen in respect to astronaut James Irwin and the lunar rover. Over a period of time, its lava may have continued to flow through this area, yet it remains forever buried beneath years of regolith.

Friday, May 25 – Tonight on the Moon we’ll be looking for another challenging feature and a crater which conjoins it – Stofler and Faraday.

Located along the terminator to the south, crater Stofler was named for Dutch mathematician and astronomer Johan Stofler. Consuming lunar landscape with an immense diameter of 126 kilometers and dropping 2760 meters below the surface, Stofler is a wonderland of small details in an eroded surrounding. Breaking its wall on the north is Fernelius, but sharing the southeast boundary is Faraday.

Named for English physicist and chemist Michael Faraday, it is more complex and deeper at 4090 meters, but far smaller at 70 kilometers in diameter. Look for myriad smaller strikes which bind the two together!

When you’re done, let’s have a look at another delightful pair that’s joined together – Gamma Virginis…

Better known as Porrima, this is one cool binary with almost equal spectral types and brightnesses. Discovered by Bradley and Pound in 1718, John Herschel was the first to predict this pair’s orbit in 1833 and state that one day they would become inseparable to all but the very largest of telescopes – and he was right. In 1920 the A and B stars had reached their maximum separation, and during 2007 they will be as close together as they will ever be. Observed as a single star in 1836 by William Herschel, its 171 year periastron will put Porrima in the exact position now as it was when Sir William saw it!

Saturday, May 26 – Are you ready to explore some more history? Then tonight have a look at the Moon and identify Alphonsus – it’s the centermost in a line of rings which looks much like the Theophilus, Cyrillus and Catharina trio.

Alphonsus is a very old, Class V crater which spans 118 kilometers in diameter and drops below the surface by about 2730 meters and contains a small central peak. Partially flooded, Eugene Shoemaker had made of study of this crater’s formation and found dark haloes on the floor. Again, this could be attributed to volcanism and Shoemaker believed them to be maar volcanoes, and the haloes to be dark ash. Power up and look closely at the central peak, for not only did Ranger 9 hard land just northeast, but this is the only area on the Moon where an astronomer has observed a change and back up that observation with photographic proof.

On November 2, 1958 Nikolai Kozyrev’s long and arduous study of Alphonsus was about to be rewarded. Some two years earlier Dinsmore Alter had taken a series of photographs from the Mt. Wilson 60″ reflector that showed hazy patches in this area that could not be accounted for. Night after night, Kozyrev continued to study at the Crimean Observatory – but with no success. During the process of guiding the scope for a spectrogram the unbelievable happened – a cloud of gas containing carbon molecules had been captured!

Selected as the last target for the Ranger photographic mission series, Alphonsus delivered 5814 spectacular high-resolution images of this mysterious region before Ranger 9 splattered nearby.

Capture it yourself tonight!

Sunday, May 27 – As we begin the evening, let’s have a look at awesome crater Clavius. As a huge mountain-walled plain, Clavius will appear near the terminator tonight in the lunar southern hemisphere, rivaled only in sheer size by similar structured Deslandres and Baily. Rising 1646 meters above the surface, the interior wall slopes gently downward for a distance of almost 24 km and a span of 225 km. Its crater-strewn walls are over 56 km thick!

Clavius is punctuated by many pockmarks and craters; the largest on the southeast wall is named Rutherford. Its twin, Porter, lies to the northeast. Long noted as a test of optics, Clavius crater can offer up to thirteen such small craters on a steady night at high power. How many can you see?

If you want to continue with tests of resolution, why not visit nearby Theta Virginis? It might be close to the Moon, but it’s 415 light-years away from Earth! The primary star is a white A-type subgiant, but it’s also a spectroscopic binary of two companions which orbit each other about every 14 years. In turn, this is orbited by a 9th magnitude F-type star which is a close 7.1 arc-seconds away from the primary. Look for the fourth member of the Theta Virginis system well away at 70 arc-seconds, but shining at a feeble magnitude 10.4.

Monday, May 14 – No galactic tour through Coma Berenices would be complete without visiting one of the most incredible “things that Messier missed.” You’ll find NGC 4565 located less than two degrees east of 17 Comae…

Residing at a distance of around 30 million light-years, this large 10th magnitude galaxy is probably one of the finest edge-on structures you will ever see. Perfectly suited for smaller scopes, this ultra-slender galaxy with the bright core has earned its nickname of “The Needle.” Although photographs sometimes show more than what can be observed visually, mid-to-large aperture can easily trace out NGC 4565’s full photographic diameter.

Although Lord Rosse in 1855 saw the nucleus of the “Needle” as stellar, most telescopes will resolve a bulging core region with a much sharper point in the center and a dark dustlane upon aversion. The core itself has been extensively studied for its cold gas and emission lines, pointing to the fact that it has a barred structure. This is much how the Milky Way would look if viewed from the same angle! It, too, shines with the light of 30 billion stars…

Chances are NGC 4565 is an outlying member of the Virgo Cluster, but its sheer size points to the fact that it is probably closer than any of the others. If we were to gauge it at a distance of 30 million years as is accepted, its diameter would be larger than any galaxy yet known!

Get acquainted with it tonight…

Tuesday, May 15 – Tonight we’ll take a closer look at the work of Abbé Nicholas Louis de la Caille (or de Lacaille). Born in 1731, the French astronomer and mapmaker was the first to demonstrate Earth’s bulge at its equator. From 1751 to 1753, he had the great fortune to observe southern skies and, putting his cartography skills to use, he mapped the southern skies and established the 14 constellations that remain in use to this day – including Musca. Even though Lacaille was best known for the constellation names, he and his productive half-inch telescope also cataloged 9766 stars in his two year observing period. Of these, one stands out for good reason – Lacaille 8760.

Its designation is also AX Microscopii, and it is a dwarf red flare star which resides only 12.9 light-years from us. While it might not seem that important, it is the target of interferometer studies in search of planets that may have formed in a “habitable zone” around life-giving stars similar to our own. Even though AX is slightly smaller than Sol, this cool main sequence star might be inhospitable due to its daily flare activity.

Since it will be awhile before the constellation of Microscopium rises high enough for southern observers to capture this star, let’s have a look at an object from Lacaille’s catalog known as I.5.

Located less than two handspans south of Spica, most of us know this globular cluster best as NGC 5139 – or Omega Centauri. As the most luminous of all globular clusters, Lacaille reported it as a “nebula in Centaurus; with simple view, it looks like a star of 3rd magnitude viewed through light mist, and through the telescope like a big comet badly bounded.” Yet, through even the most modest of today’s telescopes, Omega Centauri will explode into a fury of stars. Located about 17,000 light-years away, it took around 2 million years to form and it is believed that it may be the remnant of another galaxy’s core captured by our own. With more than one million members, it’s the size of a small galaxy in itself!

While this object is very low to northern observers, it is not impossible for those who live lower than 40 degrees north. Our atmosphere will rob this giant of a galaxy of some of its beauty, but I encourage you to try! It’s a sight you’ll never forget…

Wednesday, May 16 – Tonight is New Moon and we’re heading for the galaxy fields of Virgo about four fingerwidths east-southeast of Beta Leonis. As part of Markarian’s Chain, this set of galaxies can all be fitted within the same field of view with a 32mm eyepiece and a 12.5″ scope, but not everyone has the same equipment. Set your sights toward M84 and M86 and let’s discover!

Good binoculars and small telescopes reveal this pair with ease as a matched set of ellipticals. Mid-sized telescopes will note the western member of the pair – M84 – is seen as slightly brighter and visibly smaller. To the east and slightly north is larger M86 – whose nucleus is broader, and less intensely brilliant. In a larger scope, we see the galaxies literally “leap” out of the eyepiece at even the most modest magnifications. Strangely though, additional structure fails to be seen.

As aperture increases, one of the most fascinating features of this area becomes apparent. While studying the bright galactic forms of M84/86 with direct vision, aversion begins to welcome many other mysterious strangers into view. Forming an easy triangle with the two Messiers and located about 20 arc-minutes south lies NGC 4388. At magnitude 11.0, this edge-on spiral has a dim star-like core to mid-sized scopes, but a classic edge-on structure in larger ones.

At magnitude 12, NGC 4387 is located in the center of a triangle formed by the two Messiers and NGC 4388. NGC 4387 is a dim galaxy – hinting at a stellar nucleus to smaller scopes, while the larger ones will see a very small face-on spiral with a brighter nucleus. Just a breath north of M86 is an even dimmer patch of nebulosity – NGC 4402 – which needs higher magnifications to be detected in smaller scopes. Large apertures at high power reveal a noticeable dust lane. The central structure forms a curved “bar” of light. Luminosity appears evenly distributed end to end, while the dust lane cleanly separates the central bulge of the core.

East of M86 are two brighter NGC galaxies – 4435 and 4438. Through average scopes, NGC 4435 is easily picked out at low power with a simple star-like core and wispy round body structure. NGC 4438 is dim, but even large apertures make elliptical galaxies a bit boring. The beauty of NGC 4435 and NGC 4438 is simply their proximity to each other. 4435 shows true elliptical structure, evenly illuminated, with a sense of fading 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.

Happy hunting!

Thursday, May 17 – Today in 1835, J. Norman Lockyer was born. While that name might not stand out, Lockyer was the first to note previously unknown absorption lines while making visual spectroscopic studies of the Sun in 1868. Little did he know at the time, he had correctly identified the second most abundant element in our 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 make the connection with ancient astronomical structures such as Stonehenge and the Egyptian pyramids. (As a curious note, 14 years after Lockyer’s notation of helium, a sun-grazing comet made its appearance in photographs of the solar corona taken during a total eclipse in 1882… It hasn’t been seen since.)

If you would like to see a helium rich star, look no further tonight than Alpha Virginis – Spica. As the sixteenth brightest star in the sky, this brilliant blue/white “youngster” appears to be about 275 light-years away and is about 2300 times brighter than our own Sun. Although we cannot see it visually, Spica is a double star. Its spectroscopic companion is roughly half its size and is also helium rich.

Now, shake your fist at Spica… Because that’s all it takes to find the awesome M104, eleven degrees due west. (If you still have trouble finding M104, don’t worry. Try this trick! Look for the upper left hand star in the rectangle of Corvus – Delta. Between Spica and Delta is a diamond-shaped pattern of 5th magnitude stars. Aim your scope or binoculars just above the one furthest south.)

Also known as the “Sombrero,” this gorgeous 8th magnitude galaxy was discovered by Pierre Méchain in 1781, added by hand to Messier’s catalog and observed independently by Herschel as H I.43 – who was probably the first to note its dark inclusion. The Sombrero’s rich central bulge is comprised of several hundred globular clusters and can be hinted at in just large binoculars and small telescopes. Large aperture will revel in this galaxy’s “see through” qualities and bold, dark dustlane – making it a seasonal favorite!

Friday, May 18 – 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 science with some very accurate determinations of size. Since Comet Halley could not be spotted against the solar surface, we knew almost a century ago that the nucleus had to be smaller than about 100 km.

Tonight the slender crescent Moon will make a very brief appearance at dusk along the western skyline. If your atmosphere is very steady, why not set the telescope down on it and look for some very unusual features that will soon wash out as the Sun overtakes the moonscape. Almost central along the eastern lunar limb, look for Mare Smythii and Mare Marginis to its north. Between them you will see the long oval crater Neper bordered by Jansky at the very limb.

Once it has set and the sky has become fully dark, it is time to get serious. For the large telescope and seasoned observer, your challenge for this evening will be five and a half degrees south of Beta Virginis and one half degree west. Classified as Arp 248, and more commonly known as “Wild’s Triplet,” these three very small interacting galaxies are a real treat! Best with around a 9mm eyepiece, use wide aversion and try to keep the star just north of the trio at the edge of the field to cut glare. Be sure to mark your Arp Galaxy challenge list!

Saturday, May 19 – Tonight the Moon is a little bit older and brilliantly lit with earthshine. Power up and let’s go look for crater named for historian and theologian Denis Pétau – Petavius!

Located almost centrally along the terminator in the southeast quadrant, a lot will depend tonight on your viewing time and the age the moon itself. Perhaps when you look, you’ll see 177 kilometer diameter Petavius cut in half by the terminator. If so, this is a great time to take a close look at the small range of mountain peaks contained in its center as well as a deep rima which runs for 80 kilometers across its otherwise fairly smooth surface. To the east lies a long furrow in the landscape. This deep runnel is Palitzsch and its Valles. While the primary crater that forms this deep gash is only 41 kilometers wide, the valley itself stretches for 110 kilometers. Look for crater Haas on Petavius’ southern edge with Snellius to the southwest and Wrottesley along its northwest wall.

Once the Moon has quit the sky, let’s take a look about five degrees north of Eta Virginis for M61.

This 9.7 magnitude galaxy was discovered on May 5, 1779 by man named Barnabus Oriani while following the same comet as Charles Messier, who also observed it on the same night and mistook it for the comet itself for two additional nights. (Nice shootin’, Chuck!) Happily enough, Mr. Herschel also assigned it his own designation of H I.139 seven years later.

It is one of the largest galaxies of the Virgo Cluster and small telescopes will make out a faint, round glow with a brighter nucleus, while larger aperture will see the core as more stellar with notable spiral structure. Four supernova events have been observed in M61, as recently as 1999, and surprisingly two of them were exactly 35 years apart… But don’t confuse an event with foreground stars!

Sunday, May 20 – Celestial scenery alert! Tonight as the Sun leaves the sky, look west as the Moon, Pollux and Venus make beautiful and close companions in the twilight.

If you chose to scope tonight, we’re going in search of another lunar club challenge that will prove difficult because you’ll be working without a map. Relax! This will be much easier than you think. Starting at Mare Crisium, move along the terminator to the north following the chain of craters until you identify a featureless oval that looks similar to Plato seen on a curve. This is Endymion…and if you can’t spot it tonight don’t worry. We’ll take a look in the days ahead at some features that will point you to it!

Since tonight will be our last chance to galaxy hunt for awhile, let’s take a look at one of the brightest members of the Virgo Cluster – M49.

Located about 8 degrees northwest of Delta Virginis almost directly between a pair of 6th magnitude stars, giant elliptical M49 holds the distinction of being the first galaxy in the Virgo cluster to be discovered – and the second beyond our local group. At magnitude 8.5, this type E4 galaxy will appear as an evenly illuminated egg shape in almost all scopes, and as a faint patch in binoculars. While a possible supernova event occurred in 1969, don’t confuse the foreground star noted by Herschel with something new!

Although most telescopes won’t be able to pick this region apart – especially with the Moon so near, there are also many fainter companions near M49, including NGC 4470. But a sharp-eyed observer named Halton Arp noticed them and listed them as “Peculiar Galaxy 134” – one with “fragments!”