|
Credit & Copyright: Jeff Husted
Explanation:
Blown by fast winds from a hot, massive star,
this cosmic bubble is huge.
Cataloged as
Sharpless 2-308
it lies some 5,200 light-years away toward the constellation of
the Big Dog (Canis Major)
and covers slightly more of the sky than a Full Moon.
That corresponds
to a diameter of 60 light-years at its estimated
distance.
The massive star that created the bubble, a
Wolf-Rayet star,
is the bright one near the center of the nebula.
Wolf-Rayet stars have over 20 times the mass of the Sun and
are thought to be in a brief,
pre-supernova phase of massive star
evolution.
Fast winds from this Wolf-Rayet star create the
bubble-shaped nebula
as they sweep up slower moving material from an earlier phase of evolution.
The windblown nebula has an age of
about
70,000 years.
Relatively faint emission captured in the expansive image
is dominated by the glow of ionized oxygen atoms
mapped to violet hues.
Budget Universe:
Free APOD 2014 Calendar in PDF format
|
January February March April May June July August September October November December |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day