Messier 32 — Galaxy in Andromeda

M32 is a compact elliptical galaxy in the constellation Andromeda, located about 2.49 million light-years from Earth. It is a satellite galaxy of M31, the Andromeda Galaxy, and appears projected against the outer disk of its giant neighbor. M32 is remarkably compact for its luminosity, measuring only about 6,500 light-years in diameter yet containing roughly 3 billion stars. It harbors a supermassive black hole of about 2.5 million solar masses at its center — similar in mass to the Milky Way's central black hole. M32 is classified as a compact elliptical (cE), an unusual galaxy type thought to be the stripped remnant of a once much larger galaxy.

Easily found as a small, bright fuzzy spot right next to M31's core — it appears on the southern edge of the Andromeda Galaxy's disk, about 22 arcminutes south of M31's nucleus. In binoculars, M32 is visible as a small, round, star-like smudge. A 4-inch telescope clearly shows it as a compact, bright oval glow distinct from M31's diffuse disk. The contrast between M32's compact brightness and M31's sprawling disk is striking. M32 is best observed when M31 is high in the sky, from September through January. The companion galaxy M110 lies on the opposite side of M31.

Discovered by Guillaume Le Gentil on October 29, 1749, making it one of the earliest galaxies discovered after M31 itself. Charles Messier added it to his catalog in 1757. For centuries it was considered simply a companion nebula to M31. Modern studies suggest M32 was once a much larger galaxy — possibly a spiral — that was stripped of its outer stars and gas through tidal interactions with M31 over billions of years.