H-NGC2204
Open Cluster in Canis Major
About
Canis Major holds this old open cluster, about 13,400 light-years away and roughly 2 billion years old. It holds many blue stragglers, stars that may be the products of past mergers, and its iron content is only about 59% of the Sun's. William Herschel found it in 1785; it is in the Herschel 400.
Imaging tips
- Sources give 10–13′ across. At 1860–3110 mm on APS-C (2860–4760 mm full frame) it fits the frame.
- Faint at 22.8 mag/arcsec². One imager shooting from a Bortle 9 backyard called it very faint and quite a challenge from there.
- One imager captured it in LRGB with a mono camera and Optolong filters on a 6-inch f/4.5 scope.
- Best around December and January. It peaks near 21° from 50°N.
Facts
- Size
- 13′
- Magnitude
- 8.6
- Coordinates
- RA 6h 15.5m, Dec −18° 40′
- Framing, APS-C
- 1860–3110 mm
- Framing, full frame
- 2860–4760 mm
- Best months
- Jan, Dec
- Peak altitude
- 21° from 50°N, 36° from 35°N