Astr111 Photography Projects, Fall 2005

M110, Bruce Van Baren

M110 was discovered by Charles Messier in 1773. It is the second brighter satellite galaxy, along with M32, of the Andromeda galaxy, a member of our local group. It is classified with an additional “p” (peculiar) because of the odd structure clearly visible in this image, which is probably due to dust clouds. At the time of its discovery it was described as a normal elliptical, but is now counted as a dwarf speroidal because of its small size. Although Messier definitely discovered this object, for unknown reasons he never himself included it in his catalogue “Great Andromeda Nebula.” It is suspected that it was due to sloppiness in recording; however, Kenneth Glyn Jones finally added it in 1966.

Despite its comparatively small size, this dwarf elliptical galaxy has a remarkable system of 8 globular clusters in a halo around it. M110's mass was estimated to be between 3.6 and 15 billion solar masses. It is about the same distance as the Andromeda galaxy which is about 2.9 million light years away. The angular diameter is around 438.26 arc seconds. From this information the calculated linear diameter is 6161.75 light years.

References:
www.seds.org/messier/m/m110.html

www.en.wikipedia.org/wiki/M110_(galaxy)