Messier 32
Messier 32 (also known as M32 and NGC 221) is a dwarf "early-type" galaxy about 2,650,000 light-years (810,000 pc) from the Solar System, appearing in the constellation Andromeda. M32 is a satellite galaxy of the Andromeda Galaxy (M31) and was discovered by Guillaume Le Gentil in 1749.
| Messier 32 | |
|---|---|
Dwarf Satellite Galaxy Messier 32 | |
| Observation data (J2000 epoch) | |
| Constellation | Andromeda |
| Right ascension | 00h 42m 41.8s |
| Declination | +40° 51′ 55″ |
| Redshift | −200 ± 6 km/s |
| Distance | 2.49 ± 0.08 Mly (763 ± 24 kpc)[a] |
| Apparent magnitude (V) | 8.08 |
| Characteristics | |
| Type | cE2 |
| Apparent size (V) | 8′.7 × 6′.5 |
| Notable features | Satellite galaxy of the Andromeda Galaxy |
| Other designations | |
| M 32, NGC 221, UGC 452, PGC 2555, Arp 168, LEDA 2555 | |
The galaxy is a prototype of the relatively rare compact elliptical (cE) class. Half the stars concentrate within an effective radius (inner core) of 330 light-years (100 pc). Densities in the central stellar cusp increase steeply, exceeding 3×107 (that is, 30 million) M☉ pc−3 (that is, per parsec cubed) at the smallest sub-radii resolved by HST, and the half-light radius of this central star cluster is around 6 parsecs (20 ly). Like more ordinary elliptical galaxies, M32 contains mostly older faint red and yellow stars with practically no dust or gas and consequently no current star formation. It does, however, show hints of star formation in the relatively recent past.