PhysOrg Astronomy - 13 Apr 2010
Observations with Subaru Telescope's Prime Focus Camera (Suprime-Cam) have revealed an extended structure of the spiral galaxy Messier 81 (M81) that may hold a key to understanding the formation of galaxies. This structure could be M81's halo. Until now, ground-based telescopes have only observed individual stars in the haloes around the Milky Way and Andromeda Galaxies. Differences in M81's extended structure from the Milky Way's halo may point to variations in the formation histories of spiral galaxies.
Visible light image of spiral galaxy M81 (Suprime-Cam)