Messier 110 [1] | |
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![]() Dwarf elliptical galaxy Messier 110 in Andromeda | |
Observation data (J2000 epoch) | |
Constellation | Andromeda [2] |
Right ascension | 00h 40m 22.05446s [3] |
Declination | +41° 41′ 07.4963″ [3] |
Redshift | −0.000804±0.000010 [4] |
Heliocentric radial velocity | −241±3 [4] |
Galactocentric velocity | −62±8 [4] |
Distance | 2,690 ± 90 kly (825 ± 28 kpc) |
Apparent magnitude (V) | 8.5 [5] |
Absolute magnitude (V) | −16.5 [6] |
Characteristics | |
Type | E5 pec [7] |
Apparent size (V) | 21′.9 × 11′.0 [4] |
Other designations | |
IRAS 00376+4124, LEDA 2429, M110, MCG +07-02-014, NGC 205, PGC 2429, UGC 426, CGCG 535-014 [8] |
Messier 110, or M110, also known as NGC 205, is a dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy in the Local Group. [9]
Charles Messier never included the galaxy in his list, but it was depicted by him, together with M32, on his drawing of "Nébuleuse D'Andromède", later known as the Andromeda Galaxy. A label of the drawing indicates that Messier first saw the object in 1773. [a] [10] M110 was independently discovered by Caroline Herschel on August 27, 1783; her brother William Herschel described her discovery in 1785. [b] [10] [11] The suggestion to assign the galaxy a Messier number was made by Kenneth Glyn Jones in 1967, [12] making it the last member of the Messier List.
This galaxy has a morphological classification of pec dE5, indicating a dwarf elliptical galaxy with a flattening of 50%. It is designated peculiar (pec) due to patches of dust and young blue stars near its center. [13] This is unusual for dwarf elliptical galaxies in general, [9] and the reason is unclear. [13] Unlike M32, M110 lacks evidence for a supermassive black hole at its center. [14]
The interstellar dust in M110 has a mass of (1.1–1.8)×104 M☉ with a temperature of 18–22 K , and the interstellar gas has (4–7)×106 M☉. The inner region has sweeping deficiencies in its interstellar medium IM, most likely expelled by supernova explosions. Tidal interactions with M31 may have stripped away a significant fraction of the expelled gas and dust, leaving the galaxy as a whole, as it presents, deficient in its IM density. [15]
Novae have been detected in this galaxy, including one discovered in 1999, [16] and another in 2002. The latter, designated EQ J004015.8+414420, had also been captured in images taken by the Sloan Digital Sky Survey (SDSS) that October. [17]
About half of the Andromeda's satellite galaxies are orbiting it in a plane, with 14 out of 16 following the same sense of rotation. One theory proposes that these 16 once belonged to a subhalo surrounding M110, then the group was broken up by tidal forces during a close encounter with Andromeda. [18]