RAS News

Newsletter of RAS (Richmond Astronomical Society)
January, 2002

Visit our web site at www.richastro.org

Next meeting--Monday, Jan. 14

Meeting relocation

For the next three month, starting with this meeting, we will NOT be meeting in the planetarium but in the Orientation Room. It's off the rotunda, just to the right when you come in. It's next to the room we used to meet in, before we moved to the planetarium.

Last meeting
by Terry Barker

Ken Wilson provided printouts of this month's star maps, satellite timings, and his Leonid meteor pictures. Ken also showed off his Southern Messier Objects certificate.

Charlotte Talley, Ken Wilson, Sam Bruce, and several others all saw the Leonids Meteors, and agreed that it was a fantastic show.

Joe Hetmanski had about 250 people show up for the SMV skywatch.

Grace Suttle greeted our visitors, Nancy Brooks (Charlotte's sister), Rosemary (sorry, didn't get the last name), and Jim Lancy)

John Raymond bought five new eyepieces for the observatory.

Keith Johnson gave the short talk, on a binocular viewer he built. It uses a first surface mirror and a binocular holder to basically allow you to point the binoculars down, and see a reflection of the sky in the mirror, which allows you to see the sky by looking down, instead of up, and is much more comfortable. The binocular support allows you to change the angle of view. He made the whole assembly out of scrap wood for about $14. He got the mirror from Blackstone Mirror.

Frank Carney gave the main presentation, on Olber's Paradox, or why the night sky is not entirely lit by stars. Since there's trillions of stars, why is the night sky dark? Some explanations are: dust, a non-uniform distribution of stars, and a few others. Olbers was an 18th century doctor, and investigated the question for several year. Edgar Allen Poe actually got the right answer--there hasn't been enough time for the light from all the distant stars to reach the earth yet.

Observing Winter Deep-Sky Objects
by Kent Blackwell

The crisp, clear winter skies of January & February offer some rather interesting deep-sky objects. I’ll discuss a couple of dozen here; some are quite bright and easy for small telescopes, others will require a bit of patience and larger apertures.  I’d be interested in hearing your opinions concerning any of the objects discussed.

M 31 Andromeda.  At a distance of 2.2 million light years M 31 is one of the closest galaxies to our own, yet is also the most distant naked eye object visible from northern latitudes. I’m often amazed when amateurs are surprised to see it naked eye. It surely proves how light polluted our skies have become because M 31 is 4.5 magnitude, and therefore should present little challenge under a dark sky.  My finest view of the Great Andromeda Galaxy was with a pair of giant 20x120 binoculars. However, it’s almost equally as impressive in standard run-of-the-mill10x50s. Large telescopes are not always ideal; the galaxy is so huge the image spills out of the field of view.  If you do observe it with such telescopes simply move your scope around, noting the wonderful detail. I often go to the telescope armed with a photograph of the object. Look at the dust lanes, particularly on the SW portion.  Also note the two smaller satellite galaxies M 32 & NGC 205 (aka M 110).  M 32 is very small; in fact at low power it’s almost stellar. NGC 205, on the other hand, is larger and has low surface brightness.  Some purists refuse to call NGC 205 by its more common name of M 110 because there is some controversy as to whether Charles Messier ever observed it.

G 1 Andromeda. Are you in the mood for something difficult? How about a globular cluster near M 31? You say there is no globular in that region? Actually there is, and it lies completely outside our own galaxy. Designated as G 1, it is the brightest of all globulars in the Andromeda Galaxy. Seldom mentioned, not because of its faintness, but because it lies nearly 2 ½ degrees from M 31. If you’d like to try to find here’s the position: 00h 32m 46.5s + 39 35’ 03”.

NGC 404 Andromeda.  Many people don’t consider looking for the seldom-observed elliptical galaxy NGC 40. It’s easy to locate at only 6’ NW of the star Mirach, or Beta Andromedae.  People often don’t know about it because M 31 tends to get all the attention. The 11^th magnitude galaxy can easily be seen in telescopes as small as 3”.

M 44 in Cancer is known by several names, including Praesepe, or manger. In this case manger means a trough for feeding livestock. From information I’ve gathered the name predates the invention of the telescope. Hipparchus (130 B.C.) called it Little Cloud.

A more modern name is Beehive, and certainly describes the object’s appearance in a small telescope. I have seen the name Bee Hive (note the spelling) mentioned in “A High School Astronomy”, an 1854 book by Lewis Rutherfurd.  Visible to the naked eye the cluster contains several hundred stars.  A low power, wide-field telescope will give the best view, but moderate-to-large apertures will show no fewer than 7 galaxies embedded within M 44, all quite faint.  Are you up to the challenge? Can you see any of them in an 8” telescope? Let me know if you have any luck.

PB 1 Canis Major.  An obscure planetary nebula also known as Sa 2-2, it is seldom listed in star atlases, including Sky & Telescope’s Millennium. I have just received the new Uranometria Atlas 2000 and was glad to see it is listed in that source. You’ll also find reference to it in Stephen Hynes’ book, Planetary Nebulae. At 14^th magnitude PB 1 is only 6” in size.  Use an OIII filter, and “blink” the filter quickly between your eye and the eye lens. The object will seem to outshine similar faint stars when doing so. Because of the small size use at least 150-200x.

NGC 2359 Canis Major.  This is one of my favorite deep-sky objects, yet is often ignored in observing manuals. Sometimes called Thor’s Helmet as well as the Duck Nebula NGC 2359 is associated with a Wolf-Rayet star, a class of hot stars exceptional for their large stellar winds. The object responds very well to nebula filters. No matter what telescope you’re using don’t miss it. With a nebula filter I was able to see it in a 10x40 finderscope so don’t be intimated thinking it might be too faint for your telescope.

NGC 2362 Canis Major.   Some often refer to this as the Mexican Jumping Bean cluster. Containing 30-40 stars it’s easily found surrounding 4^h magnitude Tau Canis Majoris. Only one million years old, NGC 2362 is one of the youngest clusters known.  Tau is strongly suspected of being associated with the cluster. If so it is one of the most brilliant stars in our entire galaxy.

Stock 2 Cassiopeia.  Here’s one you won’t find on many star charts. It’s an interesting open cluster visible only in low power instruments, preferably binoculars. What’s remarkable about this little cluster is the fact it is shaped like a headless stick figure drawing of a man flexing his muscles. To find it move about 1 ½ degrees NNW of the famous Double Cluster in Perseus. Just scan the area with 7-10x binoculars. When you see it you’ll agree it’s a really a neat cluster. I seldom see it mentioned in observer’s handbooks, but certainly is worthy of viewing.

M 77 Cetus. At 81 million light-years M 77 is the most distant of all the Messier objects. It’s also the brightest member of the Seyfert galaxies. I’ve seen it in a mere 10x40 finder. If you have a small telescope don’t miss this beautiful galaxy.

IC 5146 & Sharpless 2-125 Cygnus.  The rather odd open cluster & nebula located in the western portion of Cygnus presents a real challenge to the amateur astronomer. At 7.2 magnitude the open cluster IC 5146 is quite easy to see but Sharpless 2-125, the Cocoon Nebula is quite a different story. Because of low surface brightness it’s very difficult to see visually, and a nebula filter won’t help. Your best bet is to use low power. I managed to see it in a 10” telescope at 50x, and suspect it might be visible in a 6” or 8”.  Please let me know if you see it in a smaller aperture than 10”.

M 35 & NGC 2158 Gemini. There are many beautiful open clusters in this region. Of those my favorite is M 35 in Gemini. Containing over 100 stars, M 35 lies at a distance of 2300 light years. While best at low power, higher magnifications shows even fainter stars, as well as the smaller open cluster NGC 2158. Quite ghostly, it is so tightly compacted that it resembles a globular cluster. NGC 2158 is one of the richest open clusters in our galaxy, and at 16,800 light years is one of the most distant.

NGC 2392 Gemini, known as the Eskimo and Clown Face nebula, is certainly one of the finest examples of a planetary nebula.  When viewed at 500x in telescopes larger than 12” you’ll certainly see where its name originated.  Another common name is the Blinking Planetary. To see the blinking effect stare directly at the 10.5 magnitude central star. Do you see the nebula disappear? Now try the opposite, use averted vision.  Do you now see the nebula outshine the central star? This unusual illusion is often seen in planetary nebulae, and generally occurs when the magnitude of a planetary’s central star closely matches that of the nebula itself.

NGC 3242 Hydra.  While in this area of the sky don’t miss another great planetary nebula. This rather large object has high surface brightness, making it an easy target. In a dark sky with large aperture it is simply awesome. At high power the view resembles a human eye. Even moderate magnifications show it looking much like its namesake, the Ghost of Jupiter. Another nickname aptly suited is the Eye Nebula, and highly resembles a human eye. My best view of NGC 3242 was with a 12 ½” Newtonian telescope using a 4.8mm Nagler eyepiece and a 2x Barlow lens (800x). Look carefully to see if you can detect the central star. Curiously, a nebula filter doesn’t help this nebula, but with such a high surface brightness you won’t need it anyway.

NGC 2261 Monoceros. If ever a deep-sky object looked like a comet the famous Hubble’s Variable Nebula is surely it. This object gets its name for its peculiar changes in brightness and shape, which might be caused by moving clouds of dark, cold dust. These changes have been noticed on photographs taken over the last century, so it isn’t something you’ll see change from night to night. The rather small object is shaped much like a miniature comet, and also highly resembles a badminton shuttlecock.

M 76 Perseus.  Known as the Little Dumbbell, M 76 lives up to its namesake, though is much smaller than M 27, the real Dumbbell Nebula. At 12^th magnitude M 76 is quite faint, but has relatively high surface brightness.  If you’d like to see an unusual sight look at M 76 in large apertures at 300x power or higher. To me, it looks remarkably like a barred-spiral galaxy. Remember, planetary nebulae generally hold magnification well, so don’t be afraid to push the power.

M 46 & NGC 2438 Puppis. If you enjoy viewing open clusters you’ll love 6^th magnitude M 46 containing 150 stars. Look closer and you’ll see a 10^th magnitude planetary nebula embedded within the lovely cluster. At least a 4” telescope is required to see it, and a nebula filter helps immensely. Sir William Herschel was the first to notice the planetary in 1827. The two objects are probably not related. M 46 is the more distant of the two, lying about 5,000 light-years distant.

NGC 2440 Puppis. Another planetary nebula is just 3 ½ degrees south of M 46. The twin-lobed NGC 2440 shines brightly at just under 11^th magnitude. It should be visible even in moderately light polluted areas, but for best results view it in a dark sky. Under such conditions the planetary surely belongs near the top of anyone’s observing list. Try using a nebula filter. I find the Lumicon UHC works best with apertures under 10”; the Lumicon OIII and Orion Ultra-Block are best with larger aperture telescopes

M 1 Taurus.  The Crab Nebula was the first object cataloged in Charles Messer’s list of objects. At 9^th it’s not too difficult for modern telescopes but does tend to have low surface brightness. I’ve seen it in 10x30 binoculars, but one has to know exactly where to look with such small instruments. M 1, a supernova remnant, first burst into view on July 4, 1054. Try using a nebula filter, especially if observing in light polluted skies.

NGC 1514 Taurus is a fine planetary nebula, though very low in surface brightness. The 9^th magnitude central star outshines the nebula. To see it best use a nebula filter, and I found the Lumicon UHC to be more effective on this object than the OIII filter. Glen Howell observed it with his 8” back in January 1995, and we both viewed it in my 16” that same evening. Though NGC 1514 is quite large (1.9’) use moderate-to-high power to bring out details.

M 33 Triangulum. Under a very dark sky M 33 is just barely visible to the naked eye, but it is perhaps best in binoculars. Because of low surface brightness it can be difficult in a telescope. If the sky is clear, however, M 33 can be fascinating. Under such skies look use 100x or so and look at some of the beautiful HII regions, appearing as bright knots. One such bright region has its own designation, NGC 604. 

I’ve only touched on a few deep-sky objects gracing the winter sky, omitting the Great Orion Nebula, the Pleiades and the like since much has already been written about these. The purpose here has been to touch on a few lesser-known objects, though I couldn’t resist throwing in a few warhorses. If you have a favorite please let me know. In March I’ll discuss many of the galaxies visible in the early spring sky.

Kent Blackwell
kent@exis.net

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Contact information

All meetings are the second Monday of the month, at the Science Museum of Virginia, 2500 W. Broad St. For more information, contact Terry Barker, 379-8175, or tbarker@i2020.net.

Board presentation months

The months that have been assigned for presentations by the board for 2001 are:

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