2020 March 2
Sharpless-308: The Dolphin Nebula
Image Credit & Copyright: Chilesope 2, Pleaides Astrophotography Team (Peking U.)
Image Credit & Copyright: Chilesope 2, Pleaides Astrophotography Team (Peking U.)
Explanation:
Blown by fast winds from a hot, massive star, this
cosmic bubble is much larger than the dolphin it appears to be.
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
featured expansive image
is dominated by the glow of ionized oxygen atoms
mapped to a blue hue.
