The Galactic Center
The center of our Milky Way Galaxy is located in the constellation of
Sagittarius. In visible light the lion's share of stars are hidden
behind thick clouds of dust. This obscuring dust becomes increasingly
transparent at infrared wavelengths. This 2MASS image, covering a field
roughly 10 x 8 degrees (about the area of your fist held out at arm's
length) reveals multitudes of otherwise hidden stars, penetrating all
the way to the central star cluster of the Galaxy.
This central core, seen in the upper left portion of the image, is
about 25,000 light years away and is thought to harbor a supermassive
black hole. The reddening of the stars here and along the Galactic
Plane is due to scattering by the dust; it is the same process by which
the sun appears to redden as it sets.
The densest fields of dust still show up in this mosaic. Also evident
are several nebulae to the lower right, including the Cat's Paw Nebula.
The 2MASS analysis software has identified and measured the properties
of almost 10 million stars in this spectacular field alone.