C100
Open Cluster in Centaurus
About
IC 2944, a cluster of young stars lighting a hydrogen cloud in Centaurus, about 6,500 light-years away. A group of stars in it suggested the Running Chicken nickname. Dark Bok globules, found by Thackeray in 1950, are scattered through the glow.
Imaging tips
- The cluster alone is about 5′, but the glowing region spans roughly 75′, so frame for the nebula: a wide field or a mosaic, not a long focal length.
- RGB alone leaves the region almost featureless; narrowband (Hα, OIII) brings out depth. One 54-hour project used 25 h Hα, 23 h OIII and 6 h RGB.
- OIII shows as pale blue wisps, so a bicolour Hα plus OIII image is worth planning.
- IC 2948 with the Liberty Bell nebula sits in the same complex; Collinder's 1931 list counts this cluster as Collinder 249.
- Best February to April, but it never rises from 50°N or 35°N: a southern-hemisphere target.
Facts
- Size
- 75′
- Magnitude
- 4.5
- Coordinates
- RA 11h 38.3m, Dec −63° 22′
- Framing, APS-C
- 320–540 mm
- Framing, full frame
- 490–820 mm
- Best months
- Feb, Mar, Apr
- Peak altitude
- never rises from 50°N, never rises from 35°N
Nearby
- Cr249 · 2.2′ away