M27: Not A Comet
Explanation:
While searching the skies above 18th century France for comets,
astronomer Charles Messier diligently recorded this object
as number 27 on his list of things which are
definitely not comets.
So what is it?
Well, 20th century astronomers would classify it as a
Planetary Nebula ...
but it's not a planet either, even though it may
appear round
and planet-like in a small telescope.
Messier 27 (M27) is now
known to be an excellent example of
a gaseous emission nebula created
as a
sun-like star runs out
of nuclear fuel in its core.
The nebula forms as the star's outer layers are expelled into
space, with a visible glow generated by atoms excited by the dying
star's intense but invisible
ultraviolet light.
Known by the popular name of
the "Dumbbell Nebula", the beautifully
symmetric interstellar gas cloud is about 1,200 light-years away in the
constellation Vulpecula.
This gorgeous synthetic color picture of M27
was produced during testing of one of the European Southern Observatory's
Very Large Telescopes.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
