The Crescent Nebula is a rapidly expanding shell of gas surrounding a dying star. In this recently released image [ http://oposite.stsc…] by the Hubble Space Telescope [ http://oposite.stsc…], a bright dynamic part of the nebula three light-years across is shown in representative color. The Crescent Nebula [ http://www.ne.jp/as…] began to form about 250,000 years ago as central Wolf-Rayet [ http://antwrp.gsfc.…] star WR 136 began to shed its outer envelope in a strong stellar wind [ http://www-istp.gsf…], expelling the equivalent of our Sun's mass every 10,000 years. This wind [ http://science.msfc…] has been impacting surrounding interstellar gas [ http://antwrp.gsfc.…], compacting it into a series of complex shells, and lighting it up. The Crescent Nebula [ http://www.astro.un…], also known as NGC 6888, lies about 4,700 light-years [ http://www.howstuff…] away in the constellation [ http://www.eagleque…] of Cygnus [ http://www.seds.org…] and can only be seen through a telescope. Star WR 136 [ http://adsabs.harva…] will probably undergo a supernova [ http://antwrp.gsfc.…] explosion sometime in the next million years.
Explanation
The Crescent Nebula is a rapidly expanding shell of gas surrounding a dying star. In this recently released image [ http://oposite.stsc…] by the Hubble Space Telescope [ http://oposite.stsc…], a bright dynamic part of the nebula three light-years across is shown in representative color. The Crescent Nebula [ http://www.ne.jp/as…] began to form about 250,000 years ago as central Wolf-Rayet [ http://antwrp.gsfc.…] star WR 136 began to shed its outer envelope in a strong stellar wind [ http://www-istp.gsf…], expelling the equivalent of our Sun's mass every 10,000 years. This wind [ http://science.msfc…] has been impacting surrounding interstellar gas [ http://antwrp.gsfc.…], compacting it into a series of complex shells, and lighting it up. The Crescent Nebula [ http://www.astro.un…], also known as NGC 6888, lies about 4,700 light-years [ http://www.howstuff…] away in the constellation [ http://www.eagleque…] of Cygnus [ http://www.seds.org…] and can only be seen through a telescope. Star WR 136 [ http://adsabs.harva…] will probably undergo a supernova [ http://antwrp.gsfc.…] explosion sometime in the next million years.
