|
M101: The Pinwheel Galaxy
M101 is a fine example of a spiral galaxy - a system of over 100 billion
stars, along with lots of hydrogen gas, molecular gas, and interstellar
dust. Our own Milky Way might look very much like M101 if we could view it
from above ("face-on"). Our Sun would sit about 2/3 of the way from the
bright center to the edge of this image. The area shown here is about
100,000 light years across.
M101 lies about 25 million light-years from us, in the constellation of
Ursa Major. It is only faintly visible through binoculars on a dark
moonless night. In this CCD image, the nucleus appears yellowish as it is
made of of millions of ordinary stars like our sun and cooler. The spiral
arms appear bluer - they contain newly made massive stars that are much
hotter than our sun. The colorful gas clouds surround clusters of young
stars, whose energy causes the gas to glow in the light of hydrogen (red) and
oxygen (green).
|
|
|