Explanation:
One of the last entries in Charles Messier's
famous catalog, big, beautiful spiral galaxy M101 is
definitely not
one of the least.
About 170,000 light-years across,
this galaxy is enormous, almost
twice the size of our own Milky Way Galaxy.
M101 was
also one of the original spiral nebulae
observed with Lord Rosse's large 19th century telescope, the
Leviathan
of Parsontown.
In contrast, this multiwavelength view
of the large island universe
is a composite of images recorded by space-based telescopes in the
21st century.
Color coded from X-rays to infrared
wavelengths (high to low energies),
the image data was taken from the
Chandra X-ray Observatory (purple), the
Galaxy Evolution Explorer ( blue),
Hubble Space Telescope(yellow), and the
Spitzer Space Telescope(red).
While the X-ray data trace the location of multimillion degree gas
around M101's exploded stars and neutron star and black hole binary
star systems, the lower energy data follow the
stars and dust that define M101's grand spiral arms.
Also known as the
Pinwheel Galaxy,
M101 lies within the boundaries of the northern constellation
Ursa Major, about 25 million light-years
away.
