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Gerry Descoteaux
The Lawnchair Astronomer





Appealing April
Leo
As promises of Lawnchair warmth percolate through the ether there are indeed many galactic sights to marvel at throughout the heavens during April.  From our vantage point, we are privy to hundreds of thousands of extra galactic nebulae.  From backyard-grade telescopes, hundreds of galaxies and galaxy clusters, like star clusters, can be peaked at under very dark, clear and moonless skies.  Besides the edge on and face on spirals exist several irregular galaxies.  Some are cigar shaped, while others, seemingly, have no specific shape at all, but rather resemble mishmash conglomerations of stars.  There is quite a diversity in sizes, types and shapes of our galactic neighbors.

A favorite hunting ground for many enthusiasts is the area between Leo's tail, Virgo and the boomerang-shaped Coma Berenices constellations.  Here is where you'll find tens, if not hundreds of wispy splashes of light which are collectively known as the Coma-Virgo cluster of galaxies.  This is the galactic conglomeration of which our smaller Local Group of galaxies belong.  Quite a menagerie of island universes, this relatively small area of sky is filled with very distant, and therefore, very dim nebulae.  Scan this area with a large instrument and low power eyepiece and see how many of these galaxies you can count.

Begin an adventure by scanning the towering Leo and his growling façade.  If you are so inclined and just happen to be toting the "big instrument" out for the first time this year, the area around the Big Cat is perfect for a galactic hunting expedition.  Several spiral shaped nebulae tucked beneath his belly and along his rear quarters make the Big Cat Safari a wonderful adventure all by itself.  As mentioned previously, the "piece de resistance" for telescopic adventurers, is the massive Virgo Coma Cluster of galaxies following the big cat high across the southeastern sky.  Dozens of relatively bright, wispy galaxies can be observed.  A good dark sky and a large light bucket scale telescope will help to capture some of these elusive splashes of light.  Some of the brightest of the group can be glimpsed in mid sized instruments. However, many, but not all, are quite dim.  So don't expect to see anything more than tiny, subdued splashes of light for many of them.  Ghosts really.

Though I always recommend sharing this experience with friends and family, there does come a time, occasionally, when you may want to hog the scope all to yourself.  After all, we nocturnal beasts are often loners.  Besides, there'll be plenty of warm summer nights to come, on which to share the Lawnchair.  It’s not a sin to be selfish once in a while.  Keep telling yourself that as you stare, for as long as you want, in sheer amazement over what meets you at the eyepiece.

Virgo

Next up on an April adventure, following the big cat is none other than the constellation Virgo.  Any talk of Virgo must include Spica, the star representing the bushels of wheat the Virgin holds in her left hand.  Spica is the perfect example of a first magnitude star.  Although it varies just above and below the one magnitude classification, it is listed as the 16th brightest star in the sky.

 Once you've located Virgo and Spica which lies in the zodiacal procession on the ecliptic, try tracing out the odd, box shaped body. Her arms and legs extend out from each corner of this rectangular shape. Moving up from the body of this celestial maiden is where we will concentrate our attention.  You will need to employ at least a six or eight inch telescope to take part in this adventure. The reason is that everything we'll see here is extremely far away.  These Messier objects are not even in our own galaxy. As a matter of fact they are galaxies themselves.  Even more astounding is the fact that here, in this little corner of the sky, lies what is known as the Coma Virgo cluster.  Not star clusters mind you, but clusters of galaxies. When old Charles Messier first cataloged these little light clouds in the late seventeen hundreds he had no idea of what they were.

Looking at one of the only galaxy clusters that can be detected in amateur quality/size instruments, here in the Virgo cloud are perhaps as many as ten thousand galaxies peppered throughout the immediate vicinity, many of which are only detectable within long exposure photographs. A hundred of these are visible with a good eight inch telescope from a truly dark sky site.  A dozen or so are available for viewing in smaller instruments. There are many groups of galaxies that lie even further away that only the largest instruments can detect.  The Virgo cluster is the nearest of any of the extra  galactic clusters.

Scanning this area of the sky with your telescope will reveal a large number of small, wispy light clouds.  Here you'll see what Charles Messier saw in his crude three-inch telescope. He named a dozen or so of these tiny clouds.  M 49, M 58, M 59, M 60, M 61, M 84, M 86, M  87, M 89, M 90, and M 104, the Sombrero galaxy, were all visible to him over two hundred years ago.  Which ones can you see today?

On the Coma Virgo border lies some of the brightest members of these "star cities".  Exact distances are still disputed but as for most of the Messiers, it is estimated that they reside between 40 and 70 million light years away.  In comparison our big dog neighbor, Andromeda, is only two and a half million light years from us.  So remember as you gaze at this area of the sky, that not only are you looking at galaxies that are somewhere around at least 50 million light years away, but, galaxies as they existed fifty million years ago.  Don't expect to see a lot of detail in these galaxies. What you will be able to discern will be the differences in their shapes.  Most are spirals and the remainder are what are known as irregulars and ellipticals.

How many of these galaxies can be seen will be determined by how long you let your eyes dark adapt, the local weather conditions and, the overall brightness of the sky.  Don't be disappointed if at first you do not see a hundred galaxies. Try using averted vision, or move to a darker location for observing.  Most of all, enjoy yourself as you peer into the far reaches of the Universe and the distant past.

Coma Berenices

With your eyes alone, looking just to the east (left) of Leo, Coma Berenices seemingly contains only a few stars which form a wide V or boomerang shape.  In mid Spring, by eleven p.m., Coma Berenices is directly overhead.  Here you should easily find what is known as the Coma Cluster, a close, open cluster, best viewed with binoculars.  A telescope's narrow range will miss most of this thin and widely scattered group of predominantly binary star systems.  Besides this large grouping of fairly bright stars, you'll find a pair of spectacular globular star clusters here in the constellation named for the Egyptian Queen, Berenices.

 M 53 was found by J.E. Bode two years before Charles Messier found and cataloged it independently in 1777.  In a wide angle view, less than a degree away lies a fainter, but just as magnificent star cluster, officially registered as NGC 5053.  Slightly closer to us than the much brighter M 53, this cluster does make for an interesting and contrasting view of globulars.  Finally, one last sight worth mention here inside the constrictions of Coma V is the galaxy known as M 64, or the Black Eye Galaxy. This object, also discovered by J.E. Bode, is not believed to be part of the larger Coma Virgo cluster of galaxies nearby, as it is much closer to us. What makes this particular galaxy noteworthy is its extremely dark central lanes, which of course is why it received its peculiar name.
 
On a side note, Coma Berenices contains yet another, though substantially more distant and therefore dimmer galaxy cluster.  F. Swicky. in 1957, identified and charted 29,951 galaxies brighter than 19th magnitude, centered about this group, whose brightest member, an 11th magnitude face on spiral, is cataloged as NGC 4889 near the star listed as Beta Com.  Many of those he found may belong to even more distant groups beyond this one. The main members of this group lie at about 400 million light years away from us.
 
Clear Skies!

The Lawnchair Astronomer
 
Gerry Descoteaux is the author of “The Lawnchair Astronomer,” a Dell Trades paperback. He has been writing about astronomy for more than 25 years. He also played an integral role in the development of America Online’s pioneering distance education program known as AOL’s Online Campus and served as Professor of Astronomy there for 10 years. He can be reached at TheStarMan@thelawnchairastronomer.com.

Notes From the Lawnchair












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