H-NGC7789 — Caroline's Rose
Open Cluster in Cassiopeia
About
Caroline's Rose, a rich open cluster in Cassiopeia about 7,600 light-years away. Caroline Herschel spotted it in 1783. Its stars are roughly 1.4 to 1.7 billion years old, with many red giants and an unusually large number of blue stragglers.
Imaging tips
- Plan a focal length of 970–1620 mm on APS-C, or 1490–2480 mm on full frame.
- Colour comes from broadband RGB. One imager built an image from 6 hours in total; another used 2 h 30 min of 5-minute subs (8 R, 12 G, 10 B).
- A 106 mm f/3.6 astrograph at about 1.6″ per pixel placed the cluster inside a wide Milky Way field, with some faint background galaxies visible.
- Best around September and October; from 50°N it climbs to about 83°.
Facts
- Size
- 25′
- Magnitude
- 6.7
- Coordinates
- RA 23h 56.7m, Dec +56° 43′
- Framing, APS-C
- 970–1620 mm
- Framing, full frame
- 1490–2480 mm
- Best months
- Sep, Oct
- Peak altitude
- 83° from 50°N, 68° from 35°N