The Crescent Nebula (NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5,000 light-years away. It was discovered by William Herschel, a British astronomer in 1792. The Crescent Nebula gets its power from a Wolf-Rayed star at the centre WR 136(HD 192163), an evolved massive star that sprays its outer layers into space at 2,000-3,000 km/s. This fast-moving hot gas collides with cooler and slower moving gas ejected by the star when it became a red giant around 250,000 to 400,000 years ago and the collision excites the gas that expand to about 25 light-years across to emit light. The star at the centre of the Crescent Nebula sheds mass at a tremendous rate, close to a full solar mass in just 10,000 years. Burning fuel at a prodigious rate and near the end of its stellar life, this star should ultimately go out with a bang in a spectacular supernova explosion. 9-12 April 2016, LRHa-RHaGB image total 280 minutes SBIG STT-8300 CCD camera, Takahashi CCA-250 Astrograph, 1,250 mm f/5, Astro-Physics 1200GTO. From Pakchong, Nakornratchasima, Thailand

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拍攝者： Tragoolchitr