Crescent nebula, optical image. This is a glowing shell of gas cast off by the central star WR 136 (just above and right of centre). WR 136 is a Wolf-

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Crescent nebula, optical image. This is a glowing shell of gas cast off by the central star WR 136 (just above and right of centre). WR 136 is a Wolf-Rayet star, a rare type of hot, massive star that loses mass rapidly through a strong and dusty stellar wind. The glowing shell is thought to be ejected material that is ionised by shock heating as it collides either with the interstellar medium, or with material previously ejected by the star. Also, the hydrogen in the shell is ionised by radiation from WR 136. This nebula lies around 4700 light years from Earth in the constellation Cygnus.

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Size: 3100px × 2139px
Photo credit: © ROBERT GENDLER/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 136, 6888, astronomical, astronomy, astrophysical, astrophysics, biological, crescent, cygnus, emission, hii, nebula, ngc, region, shell, shells, shock, space, star, telescope, wave, wolf-rayet, wr