Astronomy and Space

68 Cygni

68 Cygni is a star in the constellation Cygnus. Located approximately 690 parsecs (2,300 ly) distant, the star is a hot blue giant of spectral type O7.5IIIn((f)), a massive star that is likely currently expanding to become a supergiant. The star is surrounded by a ring-shaped nebula (likely a Strömgren sphere) named Sharpless 2-119 (Clamshell nebula). 68 Cygni is currently classified as a rotating ellipsoidal variable, varying between apparent magnitudes 4.98 and 5.09, although the classification as a rotating ellipsoidal variable is subject to controversy. Barely visible to the naked eye, the star is likely to have a mass of around 26 solar masses and a temperature of approximately 34,000 kelvins, although many of the star's physical parameters are subject to uncertainties due to the unclear nature of the system.

Also on this shelf

See also

• ▸Explorer 10
• ▸Churchill War Rooms
• ▸Carl Sagan

Uncatalogued shelf

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