H-NGC7790
Open Cluster in Cassiopeia
About
A young open cluster in Cassiopeia about 10,800 light-years away, estimated at 60 to 80 million years old. It contains three Cepheid variable stars, and a recent study proposes that it forms a binary cluster with its neighbour Berkeley 58.
Imaging tips
- Use 3,280–5,460 mm on APS-C; on full frame it is too small to frame, so use a long focal length and a fine pixel scale.
- Dim at 21.5 mag/arcsec², so plan long integration. One observer found the nearby Berkeley 58 hard to outline against a crowded Milky Way field.
- In an 88′-wide field from an f/4.8 scope, NGC 7788 sat just beside it, with Sharpless 168 as the brightest nebula and several dark nebulae around.
- That imager added 10 × 10 min of Hα to the luminance layer. Best around September and October.
Facts
- Size
- 7.4′
- Magnitude
- 8.5
- Coordinates
- RA 23h 58.4m, Dec +61° 13′
- Framing, APS-C
- 3280–5460 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Sep, Oct
- Peak altitude
- 79° from 50°N, 64° from 35°N