| Perseus OB1 | |
|---|---|
| | |
| Observation data (J2000 epoch) | |
| Constellation | Perseus |
| Right ascension | 02h 21m [1] [2] |
| Declination | +57.6° [1] [2] |
| Mean distance | 6.0 kly (1.83 kpc) [3] |
| Span | 1,000 × 750 light years [4] |
| Radial velocity | −43.4 [5] km/s |
| Physical characteristics | |
| Members | 149 [6] |
| OB stars | ≥65 [7] |
| Other designations | Per OB1 [1] |
Perseus OB1 is an OB association in the Northern Celestial Hemisphere in the constellation Perseus. It is centered around the double cluster (NGC 869 and NGC 884), [6] and has lent its name to the Perseus Arm of the Milky Way. [8] The brightest member of the association is the blue supergiant 9 Persei. [4]