C50
Open Cluster in Monoceros
About
The young open cluster inside the Rosette Nebula (C49), about 5,200 light-years away and under 5 million years old. Two O-type stars, HD 46223 and HD 46150, are its brightest members and ionise the gas around them. The star that looks brightest toward it, 12 Monocerotis, is a giant lying in front of the cluster.
Imaging tips
- The cluster spans about 25′; on APS-C, 970–1,620 mm frames it tightly, which leaves out most of the 80′ × 60′ nebula around it.
- To get cluster and nebula together, use the framing for C49: roughly 300–500 mm on APS-C, with C50 about 23′ from the nebula's centre.
- Surface brightness is 21.1 mag/arcsec², and the cluster's O4 and O5 stars are its brightest members.
- Best around December and January, peaking near 45° altitude from 50°N.
Facts
- Size
- 25′
- Magnitude
- 5.5
- Coordinates
- RA 6h 32.1m, Dec +4° 56′
- Framing, APS-C
- 970–1620 mm
- Framing, full frame
- 1490–2480 mm
- Best months
- Jan, Dec
- Peak altitude
- 45° from 50°N, 60° from 35°N
Nearby
- C49 (Rosette Nebula) · 22.6′ away