Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: June 11-17, 2012

Messier 5 - Credit: Hillary Mathis, REU Program/NOAO/AURA/NSF

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Greetings, fellow SkyWatchers! You can breathe now… the Venus Transit is over and we’re back to the mundane astronomical excitement like great globular clusters, an early morning conjunction and two meteor showers – the Ophiuchids and June Lyrids. If you’re up to the ordinary, then follow along as we capture some great galaxies and a very challenging study! Dust off your optics and meet me in the back yard…

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 (Right Ascension: 15 : 18.6 – Declination: +02 : 05).

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 –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 (Right Ascension: 15 : 18.6 – Declination: -24 : 04) and NGC 5898 (Right Ascension: 15 : 18.2 – Declination: -24 : 06). 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, 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.

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 (Right Ascension: 16 : 41.7 – Declination: +36 : 28). 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 – Celestial scenery alert! If you’re up before the Sun rises, be sure to check out the eastern skyline for the very close apparition of the Moon and Jupiter. The two will only be separated by about a half a degree. What a great way to wake up!

As the sky darkens tonight, let’s discover the wonderful world of low power. Start your journey by re-locating 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.

Until next week, keep your eyes on the skies!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: June 4-10, 2012

Graphic Courtesy of Dave Reneke.
Graphic Courtesy of Dave Reneke

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Greeting, fellow SkyWatchers! It’s gonna’ be a great week! We start off with a partial lunar eclipse of the Strawberry Moon, head into the historic Venus Transit, study some Herschel objects, catch both the Scorpid and Arietid Meteor Showers, practice some binocular astronomy and even take on some challenge objects! How awesome is that? Whenever you’re ready, just follow me into the back yard…

Monday, June 4 – 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!

This evening as the Sun sets and the Moon rises opposite of it, take advantage of some quiet time and really stop to look at the eastern horizon. If you are lucky enough to have clear skies, you will see the Earth’s shadow rising – like a dark, sometimes blue band – that stretches around 180 degrees of horizon. Look just above it for a Rayleigh scattering effect known as the “Belt of Venus”. This beautiful pinkish glow is caused by the backscattering of sunlight and is often referred to as the anti-twilight arch. As the Sun continues to set, this boundary between our shadow and the arch rises higher in the sky and gently blends with the coming night. What you are seeing is the shadow of the Earth’s translucent atmosphere, casting a shadow back upon itself. This happens every night! Pretty cool, huh?

For some of us, it’s eclipse time! According to NASA’s Fred Espenak, most of the Americas will experience moonset before the partial lunar eclipse ends while eastern Asia will miss the beginning of the eclipse because it occurs before moonrise. The Moon’s contact times with Earth’s shadows are: Penumbral Eclipse Begins: 08:48:09 UT, Partial Eclipse Begins: 09:59:53 UT, Greatest Eclipse: 11:03:13 UT, Partial Eclipse Ends: 12:06:30 UT, Penumbral Eclipse Ends: 13:18:17. At the instant of greatest eclipse the umbral eclipse magnitude will reach 0.3705. At that time the Moon will be at the zenith for observers in the South Pacific. In spite of the fact that just a third of the Moon enters the umbral shadow (the Moon’s southern limb dips 12.3 arc-minutes into the umbra) the partial phase still lasts over 2 hours. Be sure to visit the resource pages for a visibility map and links to precise times and locations!

Tuesday, June 5 – Heads up for all observers! Today’s universal date marks an historic event – Venus will transit the Sun! This event will cross international date lines, so be sure to know ahead of time when and where to watch. North America will be able to see the start of the transit, while South Asia, the Middle East, and most of Europe will catch the end of it. For some great information on when, where and how to watch, visit www.transitofvenus.org. If you’re clouded out, there’s plenty of resources on-line to view this rare event. One that promises to have plenty of extra bandwidth to serve visitors is Astronomy Live. Be there!!

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.

While you’re out, take the time to check out Alpha Herculis -Ras Algethi. You will find it not only to be an interesting variable, but a colorful double as well. The primary star is one of the largest known red giants and at about 430 light years away, it is also one of the coolest. Its 5.4 magnitude greenish companion star is easily separated in even small scopes – but even it is a binary! This entire star system is enclosed in an expanding gaseous shell that originates from the evolving red giant. Enjoy it tonight.

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 (Right Ascension: 12 : 15.9 – Declination: +13 : 09). 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 (Right Ascension:12 : 15.3 – Declination: +13 : 02) 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 (Right Ascension: 12 : 16.4 – Declination: +13 : 19). 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 (Right Ascension: 12 : 30.8 – Declination: +12 : 24), 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.

Why not honor Cassini’s work by visiting Saturn tonight? In case you hadn’t noticed, the beautiful yellowish “star” has been on the move and is now around a degree away to the southeast from a previous study star – Porrima! Not only is this a lovely visual, but an easy way to find Saturn if you’re new to the game. Seeing the Cassini Division in Saturn’s ring structure and some of the smaller moons will require at least a 114mm telescope and steady seeing. Use as much magnification as conditions will allow and look for unusual things – like seeing the planet edge through the gap!

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 (Right Ascension:12 : 42.0 – Declination: +11 : 39)…

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 (Right Ascension: 12 : 43.5 – Declination: +11 : 35). 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!

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?

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 (Right Ascension:12 : 21.9 – Declination: +04 : 28) 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 (Right Ascension: 12 : 20.4 – Declination: +05 : 23) is an elliptical, and by virtue of its central concentration will appear slightly larger and brighter – while southwestern NGC 4273 (Right Ascension: 12 : 19.9 – Declination: +05 : 21) 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 (Right Ascension: 12 : 19.8 – Declination: +05 : 28) north of this pairing.

Now, 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 (Right Ascension: 12 : 37.7 – Declination: +11 : 49) 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 (Right Ascension: 12 : 36.5 – Declination: +11 : 15) and NGC 4569 (Right Ascension: 12 : 36.8 – Declination: +13 : 10). 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 (Right Ascension: 12 : 36.4 – Declination: +11 : 26) to your notes.

Sunday, June 10 – 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!

Until next week? Wishing you clear skies for the Partial Lunar Eclipse, Venus Transit and the meteor showers!

Posted on by Nancy Atkinson

Timelapse of a Moonrise as Seen from the ISS

Astronaut Don Pettit continues to ‘wow’ us all with his photographic exploits. In this great timelapse video, not only does Pettit capture a stunning Moonrise over Earth, but he had the presence of mind to set up his video camera in such way that he could also show himself opening the shutters in the space station’s Cupola observation windows just in time to watch all the action. The time-lapse scene was photographed from the airlock of the ISS’s Russian segment.

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: May 28 – June 3, 2012

Hadley Rille - Credit: Damien Peach

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Greetings, fellow SkyWatchers! As the Venus Transit draws closer, our bright neighboring planet is quickly disappearing into the sunset glow. As we await this astronomical piece of history, let’s take the time this week to have a look at a host of wonderful lunar features and bright stars. Be sure to catch the conjunction of Spica, Saturn and the Moon – and to catch a shooting star from the Tau Herculid meteor shower! If you’re ready to learn more about the history, mystery and magic of astronomy, then grab your optics and meet me in the back yard…

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.

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.

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, space/time 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 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!

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, Bootes, 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 – 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!

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

Thursday, May 31 – As we begin the evening, be sure to note a splendid conjunction. Tonight the waxing Moon will dominate the sky, but it’s joined by the visage of Spica and Saturn. Look for the brilliant star located just to the lunar north and the gentle giant planet about 10 degrees or so further north.

Now, 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?

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 Bootes 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 Bootes. 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 Bootes. 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!

Now have a look at Mars. Over the last few weeks it has dropped significantly in brightness and has now reached an approximate +0.5 magnitude. Have you been watching its progress against the background stars? It won’t be long until it crosses constellation boundaries again.

Friday, June 1 – Tonight on the Moon, 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 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 – 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.

Now 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!

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.

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 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 (Right Ascension: 12 : 41.2 – Declination: +10 : 09) – 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 (Right Ascension: 12 : 39.9 – Declination: +10 : 11). Its resemblance to the planet Saturn makes it well worthwhile!

Until next week? Ask for the Moon, but keep on reaching for the stars!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: May 21-27, 2012

NGC 4038/39 - Palomar Observatory Courtesy of Caltech

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Greetings, fellow SkyWatchers! Here’s hoping you had an opportunity to witness yesterday’s eclipse! Even the partial phase here in Ohio was exciting… and to be able to watch virtually via live feeds was equally impressive! The week begins with dark skies and deep studies. Get up early to enjoy the apparition of Jupiter and Mercury just ahead of the rising Sun and check out Venus as it dances near the Earthshine Moon. When you’re ready to observe, meet me in the back yard!

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 we’ll take an exploration of space as we study an interacting pair of galaxies. All that is required is that you find 31 Corvii, an unaided eye star west of Gamma and Epsilon Corvii. Now we’re ready to nudge the scope about one degree north. The 11th magnitude NGC 4038/39 (Right Ascension: 12 : 01.9 – Declination: -18 : 52) is a tight, but superior pair of interacting galaxies. Often referred to as either the “Ringtail” or the “Antenna”, this pair deeply captured the public’s imagination when photographed by the Hubble. (Unfortunately, we don’t have the Hubble – that’s why I used a more “natural image”, but what we have is set of optics and the patience to find them.) At low power the pair presents two very stellar core regions surrounded by a curiously shaped nebulosity. Now, drop the power on it and practice patience – because it’s worth it! When that perfect moment of clarity arrives, we have crackling structure. Unusual, clumpy, odd arms appear at strong aversion. Behind all this is a galactic “sheen” that hints at all the beauty seen in the Hubble photographs. It’s a tight little fellow, but worth every moment it takes to find it.

Tuesday, May 22 – Celestial scenery alert! If you’re up before dawn this morning, look for the very close pairing of Jupiter and Mercury racing together just ahead of sunrise. The disparate pair will be less than half a degree apart. It’s worth getting up early for!

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. And speaking of the limb, did you notice bright Venus accompanying the Moon? It’s a splendid conjunction and well worth alerting friends, family and neighbors to watch for! But don’t delay… The pair will set quickly!

Now let’s visit a galaxy very similar to our own Milky Way – NGC 2903 (Right Ascension: 9 : 32.2 – Declination: +21 : 30). Located less than two degrees south of Lambda Leonis, this magnificent 9.0 magnitude barred spiral can be spotted with binoculars from a dark location, and is easily seen in a small scope.

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

Wednesday, May 23 – 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 Petau – 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.

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 – 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!

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!

Friday, May 25 – 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.

Now let’s go revisit Omega Centauri. At magnitude 3.7, NGC 5139 (Right Ascension: 13 : 26.8 – Declination: -47 : 29) is one of the few studies in the night sky receiving a Greek letter despite being decidedly “unstarlike!”

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

Saturday, May 26 – 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.

If you want to continue with tests of resolution, why not visit Theta Virginis? It might look as close as the Moon, but it’s only 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.

Sunday, May 27 – Tonight no two lunar features in the north will be more prominent than Aristoteles and Eudoxus. Why not revisit them? 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.

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!

Until next week? Ask for the Moon… But keep on reaching for the stars!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: May 14-20, 2012

NGC 4565 - Credit: Palomar Observatory, courtesy of Caltech

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Greetings, fellow SkyWatchers! Dark skies mean galactic studies and this is going to be a terrific week for sacrificing Viginis. But, hang on to your socks… Because it’s solar eclipse time! We’re talking about an annular event that occurs over a 240 to 300 kilometre-wide track which crosses eastern Asia, the northern Pacific Ocean and the western United States. It’s a generous event where a partial eclipse also occurs that includes much of Asia, the Pacific and the western 2/3 of North America. Whenever you’re ready, just meet me outside…

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 (Right Ascension: 12 : 36.3 – Declination: +25 : 59) 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 dust lane 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 Abbe 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 (that’s no type!) 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 (Right Ascension: 13 : 26.8 – Declination: -47 : 29) – 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 let’s take a look about five degrees north of Eta Virginis for M61 (Right Ascension: 12 : 21.9 – Declination: +04 : 28).

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!

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 (Right Ascension: 12 : 40.0 – Declination: -11 : 37), eleven degrees due west. (If you still have trouble finding M104 even after practicing earlier this year, 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 Mechain 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.

Once 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 (Right Ascension: 11h 46m 36s – Declination -3º 52′ 00”) 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 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 (Right Ascension: 12 : 25.1 – Declination: +12 : 53) – is seen as slightly brighter and visibly smaller. To the east and slightly north is larger M86 (Right Ascension: 12 : 26.2 – Declination: +12 : 57) – 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 is NGC 4388 (Right Ascension: 12 : 25.8 – Declination: +12 : 40). 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 (Right Ascension: 12 : 25.7 – Declination: +12 : 49) is located in the center of a triangle formed by the two Messiers and NGC 4388 (Right Ascension: 12 : 25.8 – Declination: +12 : 40). 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 (Right Ascension: 12 : 26.1 – Declination: +13 : 07) – 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 is two brighter NGC galaxies – 4435 and 4438. Through average scopes, NGC 4435 (Right Ascension: 12 : 27.7 – Declination: +13 : 05) is easily picked out at low power with a simple star-like core and wispy round body structure. NGC 4438 (Right Ascension: 12 : 27.8 – Declination: +13 : 01) 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!

Sunday, May 20 – Heads up! It’s eclipse time… According to NASA’s Fred Espenak, an annular solar eclipse will be visible from a 240 to 300 kilometre-wide track that traverses eastern Asia, the northern Pacific Ocean and the western United States. A partial eclipse is seen within the much broader path of the Moon’s penumbral shadow which includes much of Asia, the Pacific and the western 2/3 of North America. Partial phases of the eclipse are visible primarily from the USA, Canada, the Pacific and East Asia. Be sure to visit the resources pages for a visibility map and link to pages for precise times and locations!

New Moon! 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 (Right Ascension: 12 : 29.8 – Declination: +08 : 00).

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 – there are also many fainter companions near M49, including NGC 4470 (Right Ascension: 12 : 29.6 – Declination: +07 : 49). But a sharp-eyed observer named Halton Arp noticed them and listed them as “Peculiar Galaxy 134” – one with “fragments!”

Until next week? May all your journeys be at light speed!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast – May 7-13, 2012

NGC 2903 - Credit: Palomar Observatory Courtesy of Caltech

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Greetings, fellow SkyWatchers! With the Moon rising a bit later each night, it’s time to begin the galaxy hunt once again! Keep an eye on Venus as it heads quickly towards the Sun and becomes more slender and brilliant each night. Don’t forget about Mars and Saturn, too… They are both well-placed for early evening observing. When you’re ready, meet me in the back yard…

Monday, May 7 – Tonight begin your observations just as soon as it is dark and look for an object that can be viewed unaided from a dark location and is splendid in binoculars. Just northeast of Beta Leonis you’ll see a hazy patch of stars known as Melotte 111. Often called the “Queen’s Hair,” this five degree span of 5th to 10th magnitude stars is wonderfully rich and colorful. As legend has it, Queen Berenice offered her beautiful long tresses to the gods for the King’s safe return from battle. Touched by her love, the gods took Berenice’s sacrifice and immortalized it in the stars.

The cluster is best in binoculars because of its sheer size, but you’ll find other things of interest there as well. Residing about 260 light-years away, this collection is one of the nearest of all star clusters, including the Pleiades and the Ursa Major moving group. Although Melotte 111 is more than 400 million years old, it contains no giant stars, but its brightest members have just begun their evolution. Unlike the Pleiades, The Queen’s Hair has no red dwarfs and a low stellar concentration which leads astronomers to believe it is slowly dispersing. Like many clusters, it contains double stars – most of which are spectroscopic. For binoculars, it is possible to split star 17, but it will require very steady hands.

Tuesday, May 8 – Have you checked out Saturn lately? The Ring King is still hanging out with Spica. Before we leave Leo to softly exit west, there is another galaxy that is so worth your time to visit that even binoculars can spot it. You’ll need to identify slightly fainter Lambda to the southwest of Epsilon and head south about one fingerwidth for NGC 2903 (Right Ascension: 9 : 32.2 – Declination: +21 : 30).

This awesome oblique spiral galaxy was discovered by William Herschel in 1784. At a little brighter than magnitude 9, it is easily in range of most binoculars. It is odd that Messier missed this one considering both its brightness and the fact that three of the comets he discovered passed by it! Perhaps it was cloudy when Messier was looking, but we can thank Herschel for cataloging NGC 2903 as H I 56.

While small optics will only perceive this 25 million light-year distant beauty as a misty oval with a slightly brighter core region, larger aperture will light this baby up. Soft suggestions of its spiral arms and concentrations will begin to appear. One such knot is star cloud NGC 2905 – a detail in a distant galaxy so prominent that it received its own New General Catalog designation. NGC 2903 is roughly the same size as our own Milky Way, and includes a central bar – yet the nucleus of our distant cousin has “hot spots” that were studied by the Hubble Telescope and extensively by the Arecibo telescope. While our own galactic halo is filled with ancient globular clusters, this galaxy sports brand new ones!

Be sure to mark your notes with your observations, because many different organizations consider this to be on their “Best of” lists.

While your still in a Leo frame of mind, be sure to have a look at Mars before you go… Tonight the red planet has moved more than 1 AU away from Earth!

Wednesday, May 9 – While our destination tonight isn’t quite so romantic, I think you’ll enjoy getting a “Blackeye.” You’ll find it located just one degree east-northeast of 35 Coma Berenices and it is most often called M64 (Right Ascension: 12 : 56.7 – Declination: +21 : 41).

Originally discovered by Bode about a year before Messier cataloged it, M64 is about 25 million light-years away and holds the distinction of being one of the more massive and luminous of spiral galaxies. It has a very unusual structure and is classified as an Sa spiral in some catalogs and an Sb in others. Overall, its arms are very smooth and show no real resolution to any scope – yet its bright nucleus has a incredible dark dustlane that consumes the north and eastern regions around its core – giving rises to its nickname – the Blackeye Galaxy.

In binoculars, this 8.5 magnitude galaxy can be perceived as a small oval with a slightly brighter center. Small telescope users will pick out the nucleus more easily, but will require both magnification and careful attention to dark adaptation to catch the dustlane. In larger telescopes, the structure is easily apparent and you may catch the outer wisps of arms on nights of exceptional seeing.

No matter what you use to view it, this is one compact and bright little galaxy!

Thursday, May 10 – Tonight let’s use our binoculars and telescopes and return to a globular cluster we’ve studied before- M3 (Right Ascension: 13 : 42.2 – Declination: +28 : 23). You will discover this ancient beauty about halfway between the pair of Arcturus and Cor Caroli – just east of Beta Comae. There’s a reason we’re returning! Discovered by Charles Messier on May 3, 1764, this ball of approximately a half million stars is one of the oldest formations in our galaxy. At around 40,000 light-years away, this awesome globular cluster spans about 220 light-years and is believed to be as much as 10 billion years old. Now, get a grasp on this concept, because our own Sun is less than half that age!

Let’s further our understanding of distance and how it affects what we see. As you know, light travels at an amazing speed of about 300,000 kilometers per second. To get a feel for this, how many seconds are there in a minute? An hour? A week? A month? How about a year? Ah, you’re beginning to see the light! For every second – 300,000 kilometers. M3 is 40,000 years away traveling at the speed of light. In terms of kilometers – that’s far more zeros than most of us can possibly understand – yet we can still see this great globular cluster. Now let’s locate M53 near Alpha Comae. Aim your binoculars or telescopes there and you will find M53 Right Ascension: 13 : 12.9 – Declination: +18 : 10) about a degree northeast.

This very rich, magnitude 8.7 globular cluster is almost identical to M3, but look at what a difference an additional 25,000 light-years can make to how we see it! Binoculars can pick up a small round fuzzy, while larger telescopes will enjoy the compact bright core as well as resolution at the cluster’s outer edges. As a bonus for scopes, look one degree to the southeast for the peculiar round cluster NGC 5053. Classed as a very loose globular, this magnitude 10.5 grouping is one of the least luminous objects of its type due to its small stellar population and the wide separation between members – yet its distance is almost the same as that of M3.

Friday, May 11 – Tonight, start by locating 5th magnitude 6 Comae Berenices about three fingerwidths east of Beta Leonis. Remember this star! We are going on a galaxy hop to a Mechain discovery that is less than a degree west, and its designation is M98 (Right Ascension: 12 : 13.8 – Declination: +14 : 54).

At magnitude 10, this beautiful galaxy is a telescope-only challenge and a bit on the difficult side for small aperture. Long considered to be part of the Virgo Cluster, M98 is approaching us at a different rate than other cluster members, giving rise to speculation that it may simply be in the line of sight. Quite simply put, it has a blue shift instead of red! But considering that all these galaxies (and far fainter ones than we can see), are in close proximity leads some researchers to believe it is a true member by virtue of the extreme tidal forces which must exist in the area – pushing it toward us at this point in time, rather than away.

In a small telescope, M98 will appear like a slim line with a slightly brighter nucleus – a characteristic of an edge-on galaxy. To large aperture, its galactic disk is hazy and contains patchiness in structure. These are regions of newly forming stars and vast regions of dust – yet the nucleus remains a prominent feature. It’s a very large galaxy, so be sure to use a minimum of magnification and plenty of aversion to make out small details in this fine Messier object!

Saturday, May 12 – Tonight we’ll return once again to 6 Coma Berenices and head no more than a half degree southwest for another awesome galaxy – M99 (Right Ascension: 12 : 18.8 – Declination: +14 : 25).

Discovered by Pierre Mechain on the same night as he found M98, this is one of the largest and brightest of the spiral galaxies in the Virgo Cluster. Recognized second after M51 for its structure, Lord Rosse proclaimed it to be “a bright spiral with a star above.” It is an Sc class, and unlike its similarly-structured neighbors – it rotates clockwise.

Receding from us at 2324 kilometers per second, its speedy retreat through the galaxy fields and close pass to approaching M98 may be the reason that it is asymmetrical – with a wide arm extending to the southwest. Three documented supernovae have been recorded in M99 – in 1967, 1972 and 1986.

Possible in large binoculars with excellent conditions, this roughly 9th magnitude object is low surface brightness and requires clean skies to see details. For a small telescope, you will see this one as fairly large, round, wispy, and with a bright nucleus. But, unleash aperture if you have it! For large scopes, the spiral pattern is very prominent and the western arm shows well. Areas within the structure are patchworked with bright knots of stars and thin dustlanes which surround the concentrated core region. During steady seeing, a bright, pinpoint stellar nucleus will come out of hiding. A worthy study!

Sunday, May 13 – Tonight we’ll return again to 6 Comae and our hunt will be for the last of the three galaxies discovered by Mechain on that same wonderful night in 1781. You’ll find it just a fingerwidth northeast of 6. Its name is M100 (Right Ascension: 12 : 22.9 – Declination: +15 : 49).
M100 is one of the brightest member galaxies of the Virgo Cluster of galaxies – and its design is much like our own galaxy. From our point of view, we see M100 “face on,” and even Lord Rosse in 1850 was able to detect a spiral form from a mere 60,000 light years away. Thanks to its proximity to other galactic members, it has two grand arms in which recently-formed, young, hot, massive stars reside. Regardless of what seems to be perfect form, the nucleus shows that younger stars have formed more to the south side than the north. Perhaps an interaction with its dwarf neighbors?

Achievable in binoculars as a soft round glow, and about the same in a small telescope, extensive photography has shown M100 to be far larger than previously believed – with a substantial portion of its mass contained in faint outer regions. The Hubble Telescope discovered over 20 Cepheids variables and one nova contained inside our spiral friend and was more able to accurately determine its distance at 6 million light-years. In addition, NASA’s Ultraviolet Imaging Telescope has shown starburst and formation activity at the edges of M100’s inner spiral arms.

Larger telescopes will see this galaxy’s intense core region as slightly elliptical and sometimes reveal patchiness in the structure. With good sky conditions, even smaller scopes can reveal a spiral pattern, and this improves significantly with aperture. Be sure to look carefully because five supernovae events have been observed in this hot galaxy – one as recently as February 2006!

Until next week? Dreams really do come true when you keep on reaching for the stars!

Posted on by Tammy Plotner

2012 Venus Transit – The Countdown Is On!

Venus 34 Days Before 2012 Transit - Credit: John Chumack

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Head outside on any clear night this week and you won’t be able to miss brilliant Venus decorating the western horizon. Right now it’s surrounded by a host of bright winter stars like Capella, Betelgeuse, Aldebaran and the Pleiades. But, don’t stop there. Use any type of optical aid and you’ll see the planet is in the crescent phase right now and bigger than Jupiter in apparent size!

There’s a lot of things to know about viewing Venus. Oddly enough, the smaller the phase, the more brightly it shines. If you cannot see its slender form for the glare, simply try wearing sunglasses while using your binoculars… or stacking dark filters, such as green and blue, for the telescope eyepiece. While you’d think that something which sparkles and shines like Venus would be very exciting to see magnified, it’s actually pretty bland. However, don’t let rather ordinary appearances fool you. Behind that “girl next door” exterior is a really radical chick. Beneath the bland clouds runaway greenhouse gases heat things up to 860 degrees Fahrenheit (460 degrees Celsius) and volcanoes rule.

Keep on watching Venus. Right now she’s headed towards Earth and the pinnacle of observing excitement – the Transit. It will continue to grow larger in apparent size and the crescent phase will narrow even more. On June 5 (June 6 in Australia and Asia), it will pass between the Earth and Sun… an event which only happens about twice in a century and won’t happen again until the year 2117!

Venus Transit Sequence 2004 - Credt: John Chumack

The clock is ticking and now is the time to begin your preparations to view the transit of Venus. Do not wait until just a few days before the event to choose a location for your observations. If you do, you might find yourself faced with clouds… an obstruction you hadn’t planned on… getting permission to be in a certain area… or many other things. Knowing exactly where the Sun will be during the transit means a relaxed experience!

As of now, you’re going to find it will be very difficult to locate solar filters for particular telescopes – and waiting any longer may mean not having one at all. Because the transit of Venus is such a rare event, many retailers are carrying special eclipse/transit viewing glasses. They will appear much like the cardboard 3D glasses you get at the movie theatre, but instead of red and blue lenses, they will have either black mylar or Baader filter film. These glasses are safe for solar viewing, but there are a few things you must understand about them. Before you view, please inspect the edges carefully to make sure they are sealed and no sunlight can enter. Even more importantly, do not use them in conjunction with binoculars or a telescope. Eclipse glasses were meant strictly for use with your eyes. Concentrating sunlight with an optical aid and hoping the glasses will be enough to block the Sun’s harmful rays is taking a chance at blinding yourself. Always use approved solar filter material when viewing with telescopes or binoculars and always supervise when children are present.

Venus Transit 2004 - Credit: John Chumack

The next tip for viewing the Venus transit has to do with photography. If you plan on filming or photographing the event through a telescope, now is the time to practice. Do not wait until just a few days before the event to be sure your video equipment is working properly – or that your camera is prepared. Start now by taking practice pictures of the Sun and make sure you have spare batteries or a power supply on hand for the day of the event. Nothing is more disappointing than being ready to photograph an astronomical event and having your equipment fail at the last second. It’s always wise to have a back-up option… such as a cell phone camera, spare pocket camera, or even a camcorder handy just in case. All of these will work afocally. If you practice in advance, you’ll find you can take quite satisfactory photos by just holding the camera to a properly filtered telescope eyepiece.

The last tip for viewing the Venus transit is time. Make sure well in advance of exactly what time the transit starts in your area! The local transit times page by Steven van Roode and Francois Mignard is an excellent resource. But don’t forget… the times are given on an astronomical standard – Universal Time. If you are unsure of how to convert, try the Time Zone Converter to assist you.

The clock is ticking… Be ready!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: April 23-29, 2012

Mars In Leo - Credit: John Chumack

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Greetings, fellow SkyWatchers! What a great week to just enjoy some great unaided eye astronomy observations. Who can resist the beautiful appearance of Mars in Leo? Also this week, you’ll enjoy not one – but two – meteor showers as the Mu Virginids come to town mid-week and the Bootids light up the weekend. Get ready to enjoy bright stars, find planets, explore lunar features, learn some astronomy history and much more! When ever you’re ready, meet me in the back yard…

Monday, April 23 – Pioneer quantum physicist Max Planck was born on this day in 1858. In 1900, Max developed the Planck equation to explain the shape of blackbody spectra (a function of temperature and wavelength of emission). A “blackbody” is any object that absorbs all incident radiation – regardless of wavelength. For example, heated metal has blackbody properties because the energy it radiates is thermal. The blackbody spectrum’s shape remains constant, and the peak and height of an emitter can be measured against it – be it cosmic background radiation – or our own bodies.

Now, let’s put this knowledge into action. Stars themselves approximate blackbody radiators, because their temperature directly controls the color we see. A prime example of a “hot” star is Alpha Virginis, better known as Spica. Compare its color to the cooler Arcturus… What colors do you see? There are other astronomical delights that radiate like blackbodies over some or all parts of the spectrum as well. You can observe a prime example in a nebula such as M42, in Orion. By examining the radio portion of the spectrum, we find the temperature properly matches that of electrons involved in the process of fluorescence. Much like a common household fixture, this process is what produces the visible light we can see.

Tuesday, April 24 – Today in 1970, China launched its first satellite. Named Shi Jian 1, it was a successful technological and research craft. This achievement made China the fifth country to send a vessel into space.

Tonight see if you can spot the tender beginnings of the Moon after sunset. Observers take pleasure in sweeping the sky with small scopes and binoculars in hopes of finding the thinnest possible lunar crescent. And speaking of crescents, did you spot Venus close to the Moon? Why not take out your telescope and see what phase Venus is now in. If you don’t have a filter to cut its bright glare, try wearing sunglasses!

No telescope? No problem. You can still do some very awesome astronomy with just your eyes! Begin with locating the northern constellation of Ursa Major – most commonly known as the “Big Dipper”. Take note of the curve of the Dipper’s “handle” and trace it from the bottom of the cup and continue on the “Arc to Arcturus”. Keep moving, because now you’re going to “Speed on to Spica”! Once you’ve located this bright, blue/white star, simply look to its east/southeast (or upper left) for a yellow appearing “star”. That’s no star… That’s Saturn!

Now let’s have a look at 140 light-year distant Epsilon Hydrae – the northernmost star in the small circlet east of Procyon. While it and Rho will make a beautiful visual double for binoculars, Epsilon itself is a multiple system. Its A and B components are a tough split for any scope, but the 8th magnitude C star is easier. The D component is a dwarf star.

Wednesday, April 25 – Today marks the 15th anniversary of the deployment of Hubble Space Telescope. While everyone in the astronomical community is well aware of what this magnificent telescope “sees,” did you know that you can see it with just your eyes? The HST is a satellite that can be tracked and observed. Visit heavens-above.com and enter your location. This page will provide you with a list of visible passes for your area. Although you can’t see details of the scope itself, it’s great fun to track with binoculars or see the Sun glinting off its surface in a scope.

Tonight our first voyage is to the Moon’s surface. Look along the terminator in the southern quadrant and revisit ancient old crater Furnerius. Named for French Jesuit mathematician George Furner, this crater spans approximately 125 kilometers and is a lunar club challenge. Power up and look for two interior craters. The smaller is crater A and it spans a little less than 15 kilometers and drops to a depth of over 1000 meters. The larger crater C is about 20 kilometers in diameter, but goes far deeper, to more than 1400 meters. That’s about as deep as a coral will grow under the Earth’s oceans!

Keep a watch on the skies while you’re out as the Mu Virginid meteor shower reaches its peak at 7 to 10 per hour. With dark skies tonight, you still might catch one of these medium speed meteors radiating from a point near the constellation of Libra.

Thursday, April 26 – On this date in 1920, the Shapely-Curtis debate raged in Washington on the nature of and distance to spiral nebulae. Shapely claimed they were part of one huge galaxy to which we all belonged, while Curtis maintained they were distant galaxies of their own. Thirteen years later on the same date, Arno Penzias was born. He went on to become a Nobel Prize winner for his part in the discovery of the cosmic microwave background radiation, through searching for the source of the “noise” coming from a simple horn antenna. His discovery helped further our understanding of cosmology in ways that Shapely and Curtis could have never dreamed of.

Perhaps they dreamed of Moon? We’ve got Moon! No matter, what we really want to do is revisit and study a changeable, sometimes transient, and eventually bright feature on the lunar surface – crater Proclus. At around 28 kilometers in diameter and 2400 meters deep, Proclus will appear on the terminator on the west mountainous border of Mare Crisium. For many viewers tonight, it will seem to be about 2/3 black, but 1/3 of the exposed crater will be exceptionally brilliant – and with good reason. Proclus has an albedo, or surface reflectivity, of about 16%, which is an unusually high value for a lunar feature. Watch this area over the next few nights as two rays from the crater will widen and lengthen, extending approximately 322 kilometers to both the north and south. Congratulations on another lunar club challenge!

Friday, April 27 – Tonight we’re heading towards the lunar surface to view a very fine old crater on the northwest shore of Mare Nectaris – Theophilus. Slightly south of mid-point on the terminator, this crater contains an unusually large multiple-peaked central mountain which can be spotted in binoculars. Theophilus is an odd crater, one that is a parabola – with no area on the floor being flat. It stretches across a distance of 100 kilometers and dives down 440 meters below the surface. Tonight it will appear dark, shadowed by its massive west wall, but look for sunrise on its 1400 meter summit!

Now, let’s try picking up a globular cluster in Hydra that is located about 3 fingerwidths southeast of Beta Corvus and just a breath northeast of double star A8612 – M68 (Right Ascension:12 : 39.5 – Declination: -26 : 45). This class X globular was discovered in 1780 by Charles Messier and first resolved into individual stars by William Herschel in 1786. At a distance of approximately 33,000 light-years, it contains at least 2000 stars, including 250 giants and 42 variables. It will show as a faint, round glow in binoculars, and small telescopes will perceive individual members. Large telescopes will fully resolve this small globular to the core!

While you’re out, have a look at 27 Hydrae about a fingerwidth southwest of Alpha. It’s an easy double for any equipment with its slightly yellow 5th magnitude primary and distant, white, 7th magnitude secondary. Although it is wide, the pair is a true binary system.

Saturday, April 28 – Today was a very busy day in astronomy history. Newton published his Principia in 1686 on April 28. In 1774, Francis Baily was born. He went on to revise star catalogs and explain the phenomenon at the beginning and ending of a total solar eclipse which we know as “Baily’s Beads.” 1900 saw the birth of Jan Hendrick Oort, who quantified the Milky Way’s rotation characteristics and envisioned the vast, spherical area of comets outside our solar system that we now call the Oort Cloud. Last, but not least, was the birth of Bart Jan Bok in 1906 who studied the structure and dynamics of the Milky Way.

Tonight’s outstanding lunar feature will be crater Maurolycus just southwest of the three rings of Theophilus, Cyrillus and Catharina. This lunar club challenge spans 114 kilometers and goes below the lunar surface by 4730 meters. Be sure to look for Gemma Frisius just to its north.

Now let’s check out a dandy little group of stars that are about a fistwidth southeast of Procyon and just slightly more than a fingerwidth northeast of M48. Called C Hydrae, this group isn’t truly gravitationally bound, but is a real pleasure to large binoculars and telescopes of all sizes. While they share similar spectral types, this mixed magnitude collection will be sure to delight you!

For SkyWatchers, no equipment is necessary to enjoy the Alpha Bootid meteor shower – despite the Moon. Pull up a comfortable seat and face orange Arcturus as it climbs the sky in the east. These slow meteors have a fall rate of 6 to 10 per hour and leave very fine trails, making an evening of quiet contemplation most enjoyable.

Sunday, April 29 – Before we explore space, let’s have a look at the Moon and the close apparition of Regulus and Mars! The three make a wonderful “line up” the night sky! Now, let’s start our lunar observations tonight as challenge craters Cassini and Cassini A come into view just south of the black slash of the Alpine Valley. The major crater spans 57 kilometers and reaches a floor depth of 1240 meters. The challenge is to also spot the central crater A, which is only 17 kilometers wide, yet drops down another 2830 meters below the surface.

While we’re out, have a look at R Hydrae about a fingerwidth east of Gamma – which is a little more than fistwidth south of Spica. R is a beautiful, red, long-term variable first observed by Hevelius in 1662. Located about 325 light-years from us, it’s approaching – but not that fast. Be sure to look for a visual companion star as well!

Until next week? Dreams really do come true when you keep on reaching for the stars!

Many thanks to John Chumack of Galactic Images for his outstanding photo of “Leo In Mars”!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast – April 16-22, 2012

Messier 83 - Credit: Bill Schoening/NOAO/AURA/NSF

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Greetings, fellow SkyWatchers! It’s International Dark Skies Week and a great time to enjoy astronomy! We’ll start off with an impressive galaxy for even small optics and enjoy two meteor showers. There are planets and planetary nebula to explore, as well as some awesome globular clusters. If you’re in the mood, there’s some history to learn and plenty of astronomy facts! Whenever you’re ready, meet me in the back yard…

Monday, April 16 – Before binocular observers begin to feel that we have deserted them, let’s drop in on a binocular and very small telescope galaxy that resides roughly a handspan below Spica – M83 (Right Ascension: 13 : 37.0 – Declination: -29 : 52). Starhop instructions are not easy for this one, but look for a pair of twin stars just west of the easily recognized “box” of Corvus – Gamma and R Hydrae. You’ll find it about four fingerwidths further south of R.

As one of the brightest galaxies around, the “Southern Pinwheel” was discovered by Lacaille in 1752. Roughly 10 million light-years distant, M83 has been home to a large number of supernova events – one of which was even detected by an amateur observer. To binoculars it will appear as a fairly large, soft, round glow with a bright core set in a delightful stellar field. As aperture increases, so do details – revealing three well defined spiral arms, a dense nucleus and knots of stars. It is truly a beauty and will become an observing favorite!

Tuesday, April 17 – Today in 1976, the joint German and NASA probe Helios 2 came closer to the Sun than any other spacecraft so far. One of its most important contributions helped us to understand the nature of gamma ray bursts.

Are you ready for even more meteors? Tonight is the peak of the Sigma Leonids. The radiant is located at the Leo/Virgo border, but has migrated to Virgo in recent years. Thanks to Jupiter’s gravity, this shower may eventually become part of the Virginid Complex as well. The fall rate is very low at around one to two per hour. While you’re watching this region of sky, be sure to check out the close pairing of Saturn and Spica!

With tonight’s dark skies, this would be a perfect time for larger telescopes to discover an unusual galaxy grouping in Hydra about 5 degrees due west of the Xi pairing (RA 10 36 35.72 Dec -27 31 03.2).

Centralmost are two fairly easy ellipticals, NGC 3309 and NGC 3311, accompanied by spiral NGC 3322. Far fainter are other group members, such as NGC 3316 and NGC 3314 to the east of the 7th magnitude star and NGC 3305 north of the 5th magnitude star. While such galaxy clusters are not for everyone, studying those very faint fuzzies is a rewarding experience for those with large aperture telescopes.

Wednesday, April 18 – Before we have any Moon to contend with, let’s head out in search of an object that is one royal navigation pain for the northern hemisphere, but makes up for it in beauty. Start with the southernmost star in Crater – Beta. If you have difficulty identifying it, it’s the brightest star east of the Corvus rectangle. Now hop a little more than a fistwidth southeast to reddish Alpha Antilae. Less than a fistwidth below, you will see a dim 6th magnitude star that may require binoculars in the high north. Another binocular field further southwest and about 4 degrees northwest of Q Velorum is our object – NGC 3132 (RA 10 07 01.76 – Dec -40 26 11.1). If you still have no luck, try waiting until Regulus has reached your meridian and head 52 degrees south.

More commonly known as the “Southern Ring” or the “Eight Burst Planetary,” this gem is brighter than the northern “Ring” (M57) and definitely shows more details. It can be captured in even small instruments, larger ones will reveal a series of overlapping shells, giving this unusual nebula its name.

Thursday, April 19 – Today in 1971, the world’s first space station was launched – the Soviet research vessel Salyut 1. Six weeks later, Soyuz 11 and its crew of three docked with the station, but a mechanism failed denying them entry. The crew carried out their experiments, but were sadly lost when their re-entry module separated from the return spacecraft and depressurized. Although the initial phase of Salyut 1 seemed doomed, the mission continued to enjoy success through the early 1980s and paved the way for Mir.

Tonight let’s try picking up a globular cluster in Hydra that is located about 3 fingerwidths southeast of Beta Corvus and just a breath northeast of double star A8612 – M68 (Right Ascension: 12 : 39.5 – Declination: -26 : 45).

This class X globular was discovered in 1780 by Charles Messier and first resolved into individual stars by William Herschel in 1786. At a distance of approximately 33,000 light-years, it contains at least 2000 stars, including 250 giants and 42 variables. It will show as a faint, round glow in binoculars, and small telescopes will perceive individual members. Large telescopes will fully resolve this small globular to the core!

Friday, April 20 – By 1850, Lord Rosse had used the 72 inch speculum-mirrored “Leviathon at Parsontown” (Birr Castle, Ireland) to catalogue fourteen previously indecipherable glowing clouds in deep space as “spiral nebulae.” The very first one resolved was originally a discovery of Charles Messier – found while chasing a comet on the night of October 13, 1773. That discovery, M51, had to wait 72 years until large reflecting telescopes unveiled its spiral form. It would take another 75 years before M51’s extragalactic nature became an indisputable fact. Interestingly, observers have now become so accustomed to seeing spiral structure in brighter galaxies that even mid-sized scopes can see M51 (Right Ascension: 13 : 29.9 – Declination: +47 : 12) – the Whirlpool Galaxy – as a “Grand Spiral.” Tonight see what Rosse saw for yourself.

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

Saturday, April 21 – It’s Saturday night and we’ve got New Moon! Tonight, let’s use our binoculars and telescopes and take a look at a spectacular stellar sphere. Let’s find one of the best northern hemisphere globular clusters – M3! You can locate M3 (Right Ascension: 13 : 42.2 – Declination: +28 : 23) easily by identifying Cor Caroli (Alpha Canes Venatici) and Arcturus. Sweep your binoculars along a line halfway between the two and you will uncover this condensed beauty just east of Beta Comae. With added inches and magnification, the stars are out to play!

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

Now let’s check out a dandy little group of stars that are about a fistwidth southeast of Procyon and just slightly more than a fingerwidth northeast of M48. Called C Hydrae, this group isn’t truly gravitationally bound, but is a real pleasure to large binoculars and telescopes of all sizes. While they share similar spectral types, this mixed magnitude collection will be sure to delight you!

Sunday, April 22 – Today celebrates the birthday of Sir Harold Jeffreys, who was born in 1891. Jeffreys was an astrogeophysicist and the first person to envision Earth’s fluid core. He also helped in our understanding of tidal friction, general planetary structure, and the origins of our solar system.

Start your moonless morning off before dawn with a chance to view the peak of the Lyrid meteor shower. Since the radiant is near Vega, you will improve your chances of spotting them when the constellation of Lyra is as high as possible. This stream’s parent is Comet Thatcher, and it produces around 15 bright, long-lasting meteors per hour!

Before you begin your observations tonight, be sure to check out the cool triangulation of Theta Leonis, Regulus and Mars!

Let’s begin tonight in eastern Hydra and pick up another combination Messier/Herschel object. You’ll find M48 (Right Ascension: 8 : 13.8 – Declination: -05 : 48) easily just a little less than a handspan southeast of Procyon.

Often called a “missing Messier,” Charles discovered this one in 1711, but cataloged its position incorrectly. Even the smallest of binoculars will enjoy this rich galactic cluster filled with more than 50 members including some yellow giants. Look for a slight triangle shape with a conspicuous chain of stars across its center. Larger telescopes should use lowest power since this will fill the field of view and resolve splendidly. Be sure to mark your notes for both a Messier object and Herschel catalog H VI 22!

Until next week? Dreams really do come true when you keep on reaching for the stars!