Cygnus OB9
Asterism
From Wikipedia, the free encyclopedia
Cygnus OB9 is an OB association in Cygnus.[2] It is near to the Cygnus OB2 association. The region is embedded within a wider one of star formation known as Cygnus X, which is one of the most luminous objects in the sky at radio wavelengths. The region is approximately 5,000 light years from Earth in the constellation of Cygnus.[3]
| Cygnus OB9 | |
|---|---|
| Observation data (J2000.0 epoch) | |
| Right ascension | 20h 21m 00.0s[1] |
| Declination | 39° 54′ 00″ |
| Distance | 5,000 ly |
| Apparent magnitude (V) | 7.7 |
| Physical characteristics | |
| Associations | |
| Constellation | Cygnus |
Although Cygnus OB9 has many O and B type stars, Cygnus OB9 is also hidden behind a massive dust cloud known as the Cygnus Rift like Cygnus OB2.
| Star name | Spectral type | MV | Temperature (K) | Mass (M☉) |
|---|---|---|---|---|
| V2245 Cygni (HD 229196) | O5 | −6.19 | 40,862 | 61.6 |
| ALS 11244 | O5If | −5.42 | 38,612 | 40.1 |
| BD+39 4177 | O6.5 | −5.51 | 37,870 | 39.3 |
| HD 229250 | O7 | −5.28 | 36,872 | 33.9 |
| BD+39 4168 | O7 | −5.40 | 36,872 | 37.3 |
| HD 229202 | O8V | −4.66 | 34,877 | 25.0 |
| HD 228929 | B0.5Ib | −5.60 | 22,537 | 20.5 |
| HD 193945 | B0Vnn | −5.11 | 30,110 | 23.8 |
| RIC 13431720 | B1Ia | −5.91 | 19,979 | 20.5 |
| HD 193426 | B9Ia | −6.71 | 10,500 | 15.4 |
