M110 - NGC 205

Messier 110 (NGC 205) is a dwarf elliptical galaxy located approximately 2.69 million light-years from Earth in the constellation Andromeda. It is one of the satellite galaxies of the Andromeda Galaxy (M31), orbiting the much larger spiral galaxy and clearly visible in telescopic views as a fuzzy companion. M110 was first observed by Charles Messier himself, who depicted it in a drawing of M31 made in 1773, but it was not formally cataloged as a separate object until 1966, when Kenneth Glyn Jones added it to the Messier list. The galaxy was independently discovered by Caroline Herschel in 1783. M110 is classified as an E5p dwarf elliptical galaxy, with the 'p' indicating peculiar characteristics. Despite being classified as an elliptical galaxy, which are typically devoid of gas, dust, and recent star formation, M110 contains notable dark dust clouds visible in deep images and shows evidence of relatively recent star formation in its central regions. These features are unusual for an elliptical galaxy and may be related to tidal interactions with M31. M110 spans approximately 17,000 light-years along its major axis, making it considerably smaller than the Milky Way but still one of the larger satellite galaxies of M31. The galaxy has a visual magnitude of about 8.5 and an apparent size of about 22 by 11 arcminutes. It contains a modest population of about 8 globular clusters. In amateur telescopes, M110 is visible as an elongated, diffuse glow alongside M31. It is dimmer and more diffuse than M31's other bright satellite, M32, and requires darker skies to see clearly. A 4-inch telescope shows it as a faint, oval smudge, while larger instruments reveal more of its extent and the gradual brightness falloff from center to edge.

M110 spans approximately 17,000 light-years along its major axis and lies about 2.69 million light-years from Earth as a satellite of the Andromeda Galaxy.