Sh2-311
HII Region in Puppis
About
Also catalogued as NGC 2467, this star-forming region in Puppis goes by the nickname Skull and Crossbones. It was once taken for one open cluster, but is really several groups at different distances along one line of sight, so estimates run from about 4,400 to over 19,000 light-years.
Imaging tips
- One write-up gives 16′ for the bright western part and over 30′ once the faint filaments to the east are included.
- As an emission nebula it suits narrowband: one imager shot Hα, OIII and SII with five 15-minute frames each, just over 1 hour per channel.
- The skull-and-crossbones shape is only a small bright part of the glow; in that imager's field an orange, Rosette-like shape also lies left of centre.
- Reddish and visible mainly in long exposures, it still showed up in 16 four-minute frames taken with a light-pollution filter.
- Best in January; it stays low, peaking near 13.5° from 50°N.
Facts
- Size
- 45′
- Magnitude
- —
- Coordinates
- RA 7h 52.0m, Dec −26° 32′
- Framing, APS-C
- 540–900 mm
- Framing, full frame
- 820–1380 mm
- Best months
- Jan
- Peak altitude
- 14° from 50°N, 29° from 35°N