There are few objects in
the sky as inspiring as the Whirlpool Galaxy. Consisting of a
face on Sa(s)s Pec class object, it is visibly interacting with
the very bizarre NGC5195 to its left, which has been stripped
of its blue stars completely. It is classed as an IO Pec type,
very unusual. M51 is a whopping 10 x 8 arcminutes at 9th magnitude,
and its companion is 5.8 arcminutes at 10.5 magnitude. Also note
the proliferation of blue stellar associations and pink HII regions
in the spiral arms. The inclination of M51 has been measured
from the radial velocity to be 1 degree.
A plethora of
background galaxies predominate this image. One of the most interesting
is IC4278, just below NGC5195 an usual type I galaxy and looking
very much like a streaking comets trail.
To subtly emphasize
the prolific hydrogen in the arms of this galaxy, an additional
2h of Halpha data was taken through a 6nm bandpass Astrodon filter.
This was combined with the red channel at 100 percent (Halpha)
and the blue at 20 percent (Hbeta) in such a way as to not alter
the precise G2V balance of this image.