B92
Dark Nebula in Sagittarius
About
Of the two dark nebulae in M24, Small Sagittarius Star Cloud about 10,000 light-years away, this is the darker one. Barnard found it in 1913. It sits on the cloud's northwestern side and looks like a round hole in the star field.
Imaging tips
- About 15′ by 10′, which suits 1620–2690 mm on APS-C or 2480–4130 mm on full frame.
- It lies about 29′ from the centre of M24, and B93 is nearby, so a wide field can hold both against the dense star cloud.
- Dark nebulae need broadband. One imager shot LRGB with four 400 s exposures per channel in a 1.99° field that also held M24, IC 4715 and NGC 6603.
- Best around June and July, but it peaks near 22° altitude from 50°N and near 37° from 35°N.
Facts
- Size
- 15′ × 10′
- Magnitude
- —
- Coordinates
- RA 18h 15.5m, Dec −18° 13′
- Framing, APS-C
- 1620–2690 mm
- Framing, full frame
- 2480–4130 mm
- Best months
- Jun, Jul
- Peak altitude
- 22° from 50°N, 37° from 35°N