The Double Cluster
h Persei, NGC 869 | chi Persei, NGC 884 |
|
---|---|---|
Right Ascension | 2 : 19.0 (h:m) | 2 : 22.4 (h:m) |
Declination | +57 : 09 (deg:m) | +57 : 07 (deg:m) |
Distance | 7.1 (kly) | 7.4 (kly) |
Visual Brightness | 4.3 (mag) | 4.4 (mag) |
Apparent Dimension | 30 (arc min) | 30 (arc min) |
The famous double cluster in Perseus was known in antique times (probably even pre-historically), and first cataloged by the Greek astronomer Hipparcos.
Both clusters are situated in the Perseus OB 1 association, and also only a few hundred light-years appart, at a distance of over 7000 light years. They are both quite young: h is listed at 5.6, chi at 3.2 million years (Sky Catalog 2000); their hottest main sequence stars are of spectral type B0. They are approaching us at 22 (h) and 21 (chi) km/sec, respectively.
Both clusters are listed in the SAC 110 best NGC object list. The double cluster is No. 17 in the RASC Finest NGC Objects list and Caldwell 14 in Patrick Moore's list.
Last Modification: 2 Jul 1998, 21:30 MET