NGC 206 is a bright star cloud in the Andromeda Galaxy, and the brightest star cloud in Andromeda when viewed from Earth.
NGC 206 | |
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Observation data (J2000 epoch) | |
Right ascension | 00h 40m 31.3s[1] |
Declination | +40° 44′ 21″[1] |
Apparent dimensions (V) | 4.2′ (arcmin) |
Physical characteristics | |
Radius | Ca. 400 ly |
Associations | |
Constellation | Andromeda |
NGC 206 is the richest and most conspicuous star cloud in the Andromeda Galaxy, and is one of the largest and brightest star-forming regions in the Local Group.[2] It contains more than 300 stars brighter than Mb=−3.6.[3] It was originally identified by Edwin Hubble as a star cluster but today, due to its size, it is classified as an OB association.[4]
NGC 206 is located in a spiral arm of the Andromeda Galaxy, in a zone free of neutral hydrogen. It contains hundreds of stars of spectral types O and B. The star cloud has a double structure: one region has an age of around 10 million years and includes several H II regions in its border; the other region has an age of 40 to 50 million years and includes a number of cepheids. The two regions are separated by a band of interstellar dust.[5]