M1-2

About this image 

This is a color composite formed from two images of the well-known
Crab Nebula, taken on the night of October 27th 1995 with the
NOAO/STIS/Tektronix 2048x2048 CCD detector on the 3.5-meter WIYN
telescope. At the focal plane of the WIYN, this detector has a
sampling scale of 0.2 arc seconds per pixel. This picture shows the
full imaging power of the WIYN telescope: the "seeing", or image size,
is about 0.6 arc seconds, or about twice the resolution of typical
ground-based images. Some shell-like features in the center of the
nebula, and the subtle filamentary structure evident throughout the
region, are impossible to see in fuzzier (that is, more typical)
pictures. Image processing can reveal even more detail.

About this object 

The Crab Nebula was originally given this name due to its resemblance
to a crab's claw in an early sketch made in 1855 by Lord Rosse's staff
astronomer R.J. Mitchell. It is the remnant of a supernova explosion
in the year 1054 A.D., which was recorded in five separate accounts in
the Far East, although, oddly, no western observation has
survived. The nebula was probably first noticed in 1731 by John Bevis,
and it was significant enough to be the first entry in Charles
Messier's list of nebulae (compiled to avoid mistaking them for
comets). The nebula continues to expand and change the details of its
appearance, and this is partly due to the violence of the original
explosion. However, the star which exploded left behind a rotating
neutron star, which continues to beam energy out into the nebula, as
well as flashing with a period of only 33 milliseconds. The details of
this energy input are important for our understanding both of neutron
stars and of the physical conditions in the nebula, and are revealed
in the patterns of filaments, their brightness and colors, and the way
they change with time.

Minimum credit line: Jay Gallagher (U. Wisconsin)/WIYN/NOAO/NSF (for
details see Copyright Statement)