More Than Just a Pretty Crescent

First, the bare-bones truth: NGC 6888 is no showstopper. The pale object in central Cygnus known as the Crescent Nebula is barel visible without narrowband filters. But amateur astronomers embrace challenges, and NGC 6888 rewards those who scrutinize it in dark skies with large telescopes -- Mount K...

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Bibliographic Details
Published inSky and telescope Vol. 144; no. 2; p. 57
Main Author Hewitt-White, Ken
Format Magazine Article
LanguageEnglish
Published Cambridge F & W Publications, Inc 01.08.2022
Subjects
Aggressive behavior
Astronomers
Astronomy
Emissions
Helium
Radiation
Space telescopes
Stars & galaxies
Violence
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Summary:First, the bare-bones truth: NGC 6888 is no showstopper. The pale object in central Cygnus known as the Crescent Nebula is barel visible without narrowband filters. But amateur astronomers embrace challenges, and NGC 6888 rewards those who scrutinize it in dark skies with large telescopes -- Mount Kobau (sounds like "oboe") with an 18-inch f/4.5 Dobsonian. NGC 6888 certainly intrigues professional astronomers. They've designated this expanding cloud an emission nebula that's being excited by an enormous, decaying sun with the cryptic name WR 136. The WR stands for Wolf-Rayet. First noted in 1867 by French astronomers Charles Wolf and Georges Rayet, the spectra of Wolf-Rayet stars are characterized by broad emission lines predominantly of helium. Massive, luminous, and hot, they develop intense radiation pressure and winds. A Wolf-Rayet's violent behavior results in tremendous mass loss. In short, the star becomes unstable.
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ISSN:0037-6604