Thors Helmet Emission Nebula
Explanation:
This helmet-shaped cosmic cloud with
wing-like appendages is popularly called
Thor's Helmet.
Heroically sized even for a
Norse god,
Thor's Helmet spans about 30 light-years across.
In fact, the helmet is more like
an interstellar bubble, blown as a fast
wind -- from the
bright star near the center of the bubble's blue-hued region -- sweeps
through a surrounding molecular cloud.
This star, a
Wolf-Rayet star,
is a massive and extremely hot
giant star thought to be in a brief,
pre-
supernova stage of evolution.
Cataloged as NGC 2359, the
emission nebula
is located about 12,000
light-years away toward the constellation of the Big Dog
(
Canis
Major).
The
sharp image, made using broadband and narrowband filters,
captures striking details of
the nebula's
filamentary gas and dust structures.
The blue color originates from strong emission from
oxygen atoms in the nebula.
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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.
