Messier 96 — Galaxy in Leo

M96 is a spiral galaxy in the constellation Leo, located about 31 million light-years from Earth. It is the brightest member and namesake of the Leo I group (M96 group), a collection of galaxies that includes M95 and M105. Classified as type SAB(rs)ab, it is an intermediate spiral with a slightly asymmetric structure — its arms and dust lanes are not perfectly symmetric, likely due to gravitational interactions with neighboring galaxies. M96 spans approximately 66,000 light-years in diameter and has a prominent dust lane on one side that partially obscures the nucleus. The galaxy contains both young blue stars in its arms and older yellow-red stars in its central bulge.

Located in Leo about 9 degrees east of Regulus. At magnitude 9.2, M96 is the brightest of the Leo I trio and can be glimpsed in large binoculars from dark sites as a faint smudge. A 4-inch telescope shows a diffuse oval glow with a brighter core. An 8-inch telescope begins to reveal the elongated disk and hints of the dust lane. The trio of M95, M96, and M105 fits within a 1-degree field of view, making an excellent galaxy-hopping target. Best observed from February through May.

Discovered by Pierre Mechain on March 20, 1781, the same night he found M95. Charles Messier confirmed and cataloged both objects four days later. M96 was used by the Hubble Space Telescope Key Project to calibrate the cosmic distance ladder — Cepheid variable stars were identified in M96, helping refine the Hubble constant and our understanding of the expansion rate of the universe.