The Universe Revealed by Subaru Telescope Ⅲ The Milky Way and
its Group Our solar system belongs to a large spiral-shaped
group of stars called the Milky Way Galaxy, which is about
100,000 light years across. The next nearest large galactic
neighbor is the Andromeda Galaxy (M31), located 2.5 million
light-years away. It is spiral also and is similar size as the
Milky Way Galaxy. Between Andromeda and the Milky Way galaxies
there are dozens of smaller ones. The interactions between
members of this galactic group provide us with important clues
when we try to understand the mechanism of how galaxies are
formed. The World of Stars in the Andromeda Galaxy The Andromeda
Galaxy (M31) is just bright enough in our sky that it can be
recognized with the naked eye. However, since the galaxy is so
large and so close, it is difficult to observe the whole region
with a large telescope. One of the best features of the Subaru
Prime Focus Camera is its wide field of view. The camera
succeeded in taking a very clear image of