We continue our tour of the Caldwell objects. October usually offers some of the best weather and skies for deep sky observing. The objects listed should be easily visible between the onset of darkness until at least 1 am unless otherwise noted. if you missed the September objects, most can still be viewed. Info can be found here.
Caldwell 44 (NGC 7479) - [23h, 04.9m; 12°, 19']. A barred spiral galaxy in Pegasus. It's a small target with a magnitude of only 11, but it's surface brightness is fairly high making it an easy find. Look for C44 three degrees due south of magnitude 2ish Markab.
Caldwell 11 (NGC 7635, The Bubble Nebula) - [23h, 23.7m; 61°, 12']. C11 is a emission nebula in Cassiopeia. It's a very photogenic object (image by Kirby Benson shown at right), but tough to find through the eyepiece without a fairly large telescope. I was just able to see it through my 16". 20 or more inches will provide a much better view. It's located only a third of a degree SW of the bright open cluster M52. Find a dark night with excellent transparency, find M52, and jiggle your scope a bit.
Caldwell 22 (NGC 7662, The Blue Snowball Nebula) - [23h, 25.9m; 42°33']. C22 is a planetary nebula with a definite bluish hue. It appears very spherical and shows little (or no) structure through the eyepiece. It's roughly equidistant from Caph (in Cassiopeia and Scheat (in Pegasus). It's only mag 10.8, but has a moderately bright surface brightness.
Caldwell 43 (NGC 7814, The Little Sombrero) - [00h, 0.3.3m; 16°, 09m]. This edge-on galaxy in Pegasis is a junior version of M104. The core is bright. The disc you see will dependon the aperture of your telescope. It's an easy find being 2.3 degrees WNW of magnitude 2ish Algenib.
Caldwell 2 (NGC 40, The Bow-Tie Nebula) - [00h, 13.0m; 72°, 32']. William Herschel first documented the Bow-Tie Nebula in 1788. It is easily found around 5.5 degrees from third magnitude Er Rai (in Cepheus) along a line toward second magnitude Gamma Casssiopeiae. It appears faint and spherical through the eyepiece with no obvious structure.
Caldwell 72 (NGC 55) - [00h, 14.9m; -39°, 11']. C72 is a bright (mag. 8.4), irregular galaxy in Sculptor. It's appearance is somewhat similar to that of the Whale Galaxy NGC 4631 in Canes Venatici. Find NGC 55 a little under 5 degrees NW of second magnitude Ankaa (in Phoenix). It doesn't get very high above the horizon, so you may have to get down and dirty with your dob. You'll want a light-free southern horizon to find this target.
Caldwell 17 (NGC 147) - [00h, 33.2m; 48°, 30']. C17 is a dwarf elliptical galaxy located only around 2.6 million light years from Earth. It's close proximity gives the galaxy a fairly large size (roughly a third of the size of the Moon. NGC 147 is associated with M31. I saw no detail (typical for an elliptical galaxy, I guess). Find the galaxy 7.5 degrees NNW from M31 along a line toward second magnitude Caph (in Cassiopeia).
Caldwell 18 (NGC 185) - [00h, 39.0m; 48°, 20']. C18 lies just a degree east of C17. It's also a satellite dwarf galaxy of M31. It's a little larger and a little dimmer than C17.
Caldwell 1 (NGC 188) - [00h, 44.4m; 85°, 20']. C1 is a beautiful, bright (mag 8.1) open cluster in Ursa Minor. At least a couple dozen stars are clearly visible. Find the cluster 4 degrees SSW of Polaris (on a line toward second magnitude Schedar in Cassiopeia)
That's it for this month's tour.
