In the fall

The first object on our list, NGC 147 in Cassiopeia, is a satellite galaxy of the Andromeda Galaxy (M31), but not one of the two bright ones nearest it. To find NGC 147, move 1.9° west from magnitude 4.5 Omicron (ο) Cassiopeiae.

Look carefully for this challenging object. At magnitude 9.5, it seems bright for a galaxy, but that light is spread over an area 15' by 9.4'. NGC 147 is a dwarf elliptical without much apparent structure. When you do see it, you’ll notice an oval halo a bit brighter than the background glow. The galaxy is ever-so-slightly brighter toward the center, so that isn’t a foreground star.

Not quite 1° east of NGC 147, you’ll find magnitude 9.2 NGC 185, which is a dwarf spheroidal galaxy. It touts a higher surface brightness than its companion, although it’s a bit larger, measuring 14' by 12'. A 12-inch telescope reveals an oval halo with a bright core that spans two-thirds of the galaxy’s diameter.



