CONSTELLATION OF THE MONTH CASSIOPEIA by Rick Raasch The constellation of Cassiopeia is a wonderful place to lose yourself on an Autumn night. It holds many objects of interest for all instruments, binoculars to light buckets. As it lies along the Milky Way, open clusters abound. Two of my favorite open clusters are in this constellation. There are also emission nebulae and a couple of galaxies. The following list of objects is just a sampling of those inhabiting this region. M-52 This is a fine open cluster. It is about 12' in diameter, and is composed of relatively bright stars reasonably concentrated to the center. It stands out well from the background, and is dominated by a bright red star. Less than a degree away is NGC 7635 (also known as the Bubble Nebula), a large, faint emission nebula. I was unable to see it in my 10" SCT on a less than perfect night in September. M-103 This cluster is rather small, about 8' in diameter, containing about 20 relatively bright stars, loosely concentrated. Binoculars show a slightly hazy patch. NGC 663 Very close to M-103, this open cluster is much more impressive than that object, and is partially resolved in binoculars. It is well detached from the background and is moderately concentrated. I counted 10- 12 bright stars and about 50 fainter stars. NGC 7789 One of my favorite open clusters, this object is about 15' in diameter and is composed of hundreds of stars. It more resembles a loose globular cluster than an open cluster, and is made up of 10th th 11th magnitude stars, making it bright and flashy. This is a real showpiece object. NGC 7788/90 These two open clusters lie directly north of the previous object, and are easily fit into the same field of view. While not as glitzy as the Double Cluster in Perseus, they do make a nice pair. 7788 is about 4-5' in diameter and is composed of about 10-12 stars. 7790 is a bit larger and brighter. Well worth the look. NGC 457 This is another real jewel. Sometimes known as the Owl Cluster, its 75-100 bright members form the shape of a face on owl with outstretched wings and the bright double star Phi Cas as its eyes. This cluster is easily seen in binoculars and lies in a beautiful region. NGC 281 This is a large emission nebula which is faintly seen in binoculars, but really needs aperture to appreciate. Seen well with a UHC filter, it shows a rough triangle or kidney bean shape with a curving, comma shaped appendage extending to the south. Dark patches here and there add interest to the view. This relatively unknown object deserves closer scrutiny. NGC 185/147 These are both small and faint elliptical galaxies which are of some interest as they are members of our Local Group. They appear to be satellites of the Great Andromeda Galaxy. Alpha Cas An easily split pair. The yellow primary is very bright compared to the faint blue secondary. Eta Cas A very pretty yellow-white and red-gold pair, easily split. ADS 1 A fine double star. It shows a yellow primary and an easily seen blue secondary. CONSTELLATION OF THE MONTH by Rick Raasch LEO The last few months, we have been surveying constellations that lie along or close the Milky Way and offered many bright open clusters, planetary nebulae, and diffuse nebulae. In contrast to those constellations, Leo lies far enough away from the Milky Way to let us peer into extragalactic space. As such, we will no longer be looking at objects that are "merely" a few hundred or thousand light years away; the distance to the galaxies of Leo is on the order of twenty to thirty MILLION light years. Thus, these objects in general are not flashy and splashy, but rather yield their detail in subtle ways. Besides adequate dark adaptation of one's eyes, the most useful technique for coaxing details out of galaxies is averted vision. By looking slightly away from your target while keeping your attention on it, features such as spiral arms and subtle mottling can become apparent where none was before. Galaxies force you to make observations the old fashioned way: you EARN them! M-65 This galaxy is relatively large and bright, with a bright center and a stellar core. It is elongated in the north-south direction, and appears about 8'x2' in extent. It is in the same low power field of view as the next two objects. M-66 Smaller than M-65, this galaxy is wider, about 6'x3', and brighter. It also has a bright core, and is extended in the southeastern direction. Averted vision at reveals some mottling and indications of spiral structure. NGC-3628 Large, 10'x2', and oriented northwest-southeast, this object is faint overall, but averted vision shows a spindle-like shape with hints of a dust lane on the southwest side. A very interesting galaxy. M-95 Round, about 3' in diameter with a bright core surrounded by a faint halo. This is a barred spiral, but on a recent less-than-perfect night in Oklahoma, I failed to see this structure. M-96 This galaxy is ovoid, 4'x3', extended north-south with a bright core. Its core is large and non-stellar, about 1' in diameter. M-105 An elliptical galaxy, this object is relatively bright and appears round, about 3' in diameter, and has a bright central core. NGC-2903 Large and relatively bright, this galaxy appears to be about 8'x4', extended NNE-SSW, with a large, 1'x1' core. Some mottling is noticeable, and a darker area was noted on the western side. Gamma This is a fine double star, although medium powers may be needed to split it. It shows a pretty pair of almost equally bright yellow stars. Wolf 359 This is a faint red dwarf star that would be unremarkable except that it is one of our closest neighbors in space. Only Alpha Centauri and Barnard's star are closer. It is one of the least luminous stars known, shining with the luminosity of about 1/63,000 that of the sun. It has only about 8% the mass of the sun and is approximately the size of Jupiter. To find it, use a chart such as that in Burnham's Celestial Handbook, and be patient: it shines at a magnitude of 13.6.