M47
Open Cluster in Puppis
About
An open cluster in Puppis about 1,600 light-years away and roughly 78 million years old, dominated by hot B-type stars. For centuries it was considered a lost Messier object because of a position error, solved only in 1959.
Imaging tips
- About 30′ across: 810–1,350 mm on APS-C frames it with room around it.
- M46 lies about a degree away and is much older and farther. One team fitted both in one field up to about 800 mm, with a cluster in each corner.
- Mostly blue B-type stars, with red giants among the brightest members adding colour contrast, so the colour of the brightest stars is worth keeping.
- Low for northern observers: it stays below 26° from 50°N. Best in December and January.
Facts
- Size
- 30′
- Magnitude
- 4.4
- Coordinates
- RA 7h 36.6m, Dec −14° 30′
- Framing, APS-C
- 810–1350 mm
- Framing, full frame
- 1240–2060 mm
- Best months
- Jan, Dec
- Peak altitude
- 26° from 50°N, 41° from 35°N