C1
Open Cluster in Cepheus
About
Cepheus holds this cluster, about 6,000 light-years away and within 5° of the north celestial pole. Its age ranks among the greatest of any open cluster, and its high position above the galactic disk is the likely reason it has stayed together.
Imaging tips
- At 14′ across it fills a good part of the frame at 1,730–2,890 mm on APS-C.
- Faint for a cluster at 22.5 mag/arcsec², so a dark, transparent sky helps.
- Its stars are mostly old and red-gold, with few blue ones left, so expect warm colour; one 150 mm f/7 image used about 3 hours of RGB in 10-minute subs.
- Best around September and October; it peaks near 55° from 50°N.
Facts
- Size
- 14′
- Magnitude
- 8.1
- Coordinates
- RA 0h 48.4m, Dec +85° 15′
- Framing, APS-C
- 1730–2890 mm
- Framing, full frame
- 2650–4420 mm
- Best months
- Sep, Oct
- Peak altitude
- 55° from 50°N, 40° from 35°N