H-NGC2539
Open Cluster in Puppis
About
A moderately rich open cluster near the northern edge of Puppis, about 4,440 light-years away and roughly 24 light-years across. Its age is usually given as about 370 million years, and its red giants include several binaries and a triple system. Herschel found it in 1785.
Imaging tips
- Framing runs 1,100–1,840 mm on APS-C, or 1,690–2,810 mm on full frame.
- The bright star 19 Puppis sits at the cluster's edge but lies much nearer than the cluster, so it is a foreground star that will sit in the frame.
- One refractor image used sixteen 1.5-minute RGB exposures; another imager stacked six 8-minute exposures from a 700 mm f/5.6 setup.
- At 21.8 mag/arcsec² it is not very faint, and it lies along the Milky Way as seen in winter, so expect many background stars.
- Best in January and February, peaking near 27° from 50°N.
Facts
- Size
- 22′
- Magnitude
- 6.5
- Coordinates
- RA 8h 10.6m, Dec −12° 50′
- Framing, APS-C
- 1100–1840 mm
- Framing, full frame
- 1690–2810 mm
- Best months
- Jan, Feb
- Peak altitude
- 27° from 50°N, 42° from 35°N