Elliptical Galaxy M-110 (NGC 205)

Elliptical Galaxy M-110
A 60 minute exposure with an SBIG STL-1301E camera thru Kopernik's 20-inch RC Cassegrain working at F/5.3. The field of view is about 20x25 arc minutes with North at the top.

Charles Messier: (in "Observations Astronomiques, 1770-1774"; Connaissance des Tems, Paris, 1798):

'On August 10, 1773, I examined, under a very good sky, the beautiful nebula of the girdle of Andromeda [M31], with my achromatic refractor, which I had made to magnify 68 times, for creating a drawing like the one of that in Orion [M42] (Mém. de l'acad. 1771, pag. 460). I saw that nebula which C. [Citizen] Legentil discovered on October 29, 1749 [M32]. I also saw a new, fainter one, placed north of the great nebula, which was distant from it about 35' in right ascension and 24' in declination. It appeared to me amazing that this faint nebula has escaped discovery by the astronomers and myself, since the discovery of the great nebula by Simon Marius in 1612, because when observing the great nebula, this small one is located in the same field [of view] of the telescope...... '

Welch, Sage, & Mitchell: (in "The Puzzling Features of the Interstellar Medium in NGC 205"; Astrophysical Journal, 1998):

'It has long been suggested that NGC 205 has interacted with M31 in the past.... The recent (burst of star formation) could have been triggered by the interaction, and the blast waves from ensuing supernovae would then have removed most of the remaining gas. Sufficient time has passed since these events for planetary nebulae to have contributed most of the gas we see in this galaxy.....'

NGC 205 (M110) is a dwarf Elliptical Galaxy and is one of two companions of M-31 (the Andromeda Galaxy; also see M-32). The well-defined nucleus contains a young stellar population, and as the image above shows, the galaxy contains two dust patches. All of these features are rather odd for an elliptical galaxy and probably result from a past interaction with M-31. The galaxy has a rather low surface brightness and can be easily missed when observing M-31 with a small backyard telescope.

M-110 & the Messier Catalog: This object was discovered by Messier on August 10, 1773, but he never included it in his published catalog which ended at M-102. The object was independently discovered by Caroline Herschel in 1783. Messier did discuss this object in an article published in 1798, and also included it in his published sketch of M-31. However these references were forgotten until 1960 when, in his book on the Messier Objects and an article in "Sky & Telescope", Kenneth Glyn Jones suggested that NGC 205 be included in modern listings of the Messier Catalog as M-110 in recognition of Messier's discovery.