Zeta Oph: Runaway Star
Image Credit: NASA, JPL-Caltech, Spitzer Space
Telescope
Explanation: Like a ship plowing through cosmic seas,
runaway star Zeta Ophiuchi produces the arcing
interstellar bow wave or bow shock seen in this
stunning
infrared portrait. In the false-color view, bluish Zeta Oph, a star about 20
times more massive than the Sun, lies near the center of the frame, moving
toward the left at 24 kilometers per
second. Its strong stellar wind
precedes it, compressing and heating the dusty
interstellar material and
shaping the curved shock front. Around it are clouds of relatively undisturbed
material. What set this star in motion? Zeta Oph was likely once a member of a
binary star system, its companion star was more
massive and hence
shorter
lived. When the companion
exploded as a
supernova catastrophically losing mass, Zeta Oph was flung out of the
system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than
the Sun and would be one of the brighter stars in the sky if it weren't
surrounded by obscuring dust. The image spans about 1.5 degrees or 12
light-years at the estimated distance of
Zeta Ophiuchi.
Best of APOD 2012: Download a free
2013