| NGC 206 | |
|---|---|
 NGC 206 | |
| Observation data (J2000epoch) | |
| Right ascension | 00h 40m 31.3s[1] |
| Declination | +40° 44′ 21″[1] |
| Absolute magnitude (V) | Unknown |
| Apparent dimensions (V) | 4.2′ (arcmin) |
| Physical characteristics | |
| Radius | Ca. 400 ly |
| Associations | |
| Constellation | Andromeda |
| See also:Open cluster,List of open clusters | |
NGC 206 is a brightstar cloud in theAndromeda Galaxy, and the brightest star cloud in Andromeda when viewed fromEarth. It was discovered by German-born English astronomer William Herschel in 1786[2] and possibly even two years earlier when he observed "a streak of milky nebulosity, horizontal, or part of the 31st Nebula."
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 theLocal Group.[3] It contains more than 300 stars brighter than Mb=−3.6.[4] It was originally identified byEdwin Hubble as a star cluster but today, due to its size, it is classified as anOB association.[5]
NGC 206 is located in aspiral arm of the Andromeda Galaxy, in a zone free ofneutral hydrogen. It contains hundreds of stars ofspectral typesO andB. The star cloud has a double structure: one region has an age of around 10 million years and includes severalH II regions in its border; the other region has an age of 40 to 50 million years and includes a number ofcepheids. The two regions are separated by a band ofinterstellar dust.[6]
| Location | Andromeda Galaxy → Andromeda subgroup →Local Group →Local Sheet →Local Volume →Virgo Supercluster →Laniakea Supercluster →Pisces–Cetus Supercluster Complex →Local Hole →Observable universe →Universe Each → may be read as "within" or "part of". | .jpg) |
|---|---|---|
| Satellite galaxies |
*It is uncertain whether these are companion galaxies of the Andromeda Galaxy | |
| Catalogued stars | ||
| Other | ||
