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Астронет: Астрономическая картинка дня Шарплесс 308: звездный пузырь http://variable-stars.ru/db/msg/1373018/eng |
Credit & Copyright: Anis Abdul
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 a blue hue.
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.