C94 — Jewel Box
Open Cluster in Crux
About
An open cluster in Crux of just over 100 stars, placed at roughly 5,000 to 6,500 light-years by different sources. At about 14–16 million years few known open clusters are younger, and it includes the red supergiant DU Crucis.
Imaging tips
- At 2420–4040 mm on APS-C (3710–6190 mm full frame) its 10′ spread fits comfortably in the frame.
- One 10-hour LRGB stack (48 × 5 min luminance, 24 × 5 min per colour) was made at 1945 mm f/4.5.
- Bright for a cluster at 17.8 mag/arcsec², so exposure time goes mostly into colour and a clean star field rather than faint detail.
- Never rises from 50°N or 35°N (peaks near −20° and −5°). From the south it is best in March and April.
Facts
- Size
- 10′
- Magnitude
- 4.2
- Coordinates
- RA 12h 53.8m, Dec −60° 22′
- Framing, APS-C
- 2420–4040 mm
- Framing, full frame
- 3710–6190 mm
- Best months
- Mar, Apr
- Peak altitude
- never rises from 50°N, never rises from 35°N