Messier 32

Messier 32 (also known as NGC 221) is a dwarf "early-type" galaxy about 2.65 million light-years from Earth. It is seen in the constellation Andromeda.

The M32 galaxy

In this image of the Andromeda Galaxy, Messier 32 is to the left of the center.

M32 is a satellite galaxy of the large Andromeda Galaxy (M31). It was discovered by Guillaume Le Gentil in 1749. M32 measures 6.5 ± 0.2 thousand light-years in diameter at the widest point.^[1]

The galaxy is a compact elliptical galaxy type. Compact ellipticals are rather rare. Half the stars are inside an effective radius of only 100 parsecs.^[2][3]

Densities in the central area increase steeply, over 3×10⁷ M_⊙ pc⁻³ as seen by the HST.^[4] The half-light radius of this central star cluster is around 6 parsec.^[5] In other words, this small centre of the galaxy emits half the light of the central 100 parsecs.

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.^[6] It does, however, show hints of star formation in the relatively recent past. ^[7][8]

M32 contains a supermassive black hole. Its mass is between 1.5 and 5 million solar masses.^[9]

It is believed by astronomers that Messier 32 is the remnant of the former galaxy in the local group called M32p.