H-NGC637
Open Cluster in Cassiopeia
About
A compact, young open cluster in Cassiopeia, about 7,000 light-years away in the Perseus Arm and roughly 10 million years old. Four of its stars are β Cephei variables, an unusually large number for one open cluster. It is in the Herschel 400 list.
Imaging tips
- At about 4′ across it is too small to frame: use a long focal length and a fine pixel scale.
- One imager took 870 s on an 8.5-inch f/6 Newtonian with a DSLR at prime focus and a light-pollution filter; the page gives no sub length.
- Its surface brightness is 19.8 mag/arcsec², well below the faint mark of about 22, so the cluster is not a low-contrast target.
- Best in September to November; it peaks near 76° from 50°N.
Facts
- Size
- 4′
- Magnitude
- 8.2
- Coordinates
- RA 1h 43.1m, Dec +64° 2′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Sep, Oct, Nov
- Peak altitude
- 76° from 50°N, 61° from 35°N