A Galaxy is not a Comet
Credit & Copyright:
Juan Carlos Casado
This gorgeous galaxy and
comet portrait was recorded on April 5th, 2002,
in the skies over the Oriental Pyrenees near Figueres,
Spain.
From a site above 1,100 meters,
astrophotographer
Juan Carlos Casado used a guided time exposure, fast film, and
a telephoto lens to capture the predicted conjunction of
the bright Comet Ikeya-Zhang (right)
and the Andromeda Galaxy (left).
This stunning celestial scene would also have been a
rewarding one for the influential 18th century comet
hunter Charles Messier.
While Messier scanned French skies for comets,
he carefully cataloged positions of things which were
fuzzy and comet-like
in appearance but did not move against the background stars and
so were definitely not comets.
The Andromeda Galaxy,
also known as M31, is the 31st object in
his famous
not-a-comet catalog.
Not-a-comet object
number 110, a late addition to Messier's catalog, is
one of Andromeda's small satellite galaxies, and can be
seen here just below M31.
Our modern
understanding
holds that the Andromeda galaxy is a large spiral galaxy
some 2 million light-years
distant.
The photogenic
Comet
Ikeya-Zhang, then a lovely sight in
early morning skies
was about 80 million kilometers (4 light-minutes) from planet Earth.