B87 — Parrot's Head
Dark Nebula in Sagittarius
About
A dark nebula in Sagittarius, about 12′ by 7′, listed in Barnard's catalogue of dark markings. Dark nebulae are dense clouds of dust, often part of molecular clouds, that hide the light of whatever lies behind them.
Imaging tips
- Spans about 12′ by 7′, which suits 2020–3370 mm on APS-C or 3090–5160 mm on full frame.
- Dark nebulae need broadband imaging: the cloud shows only as a silhouette against the Milky Way star field behind it.
- Best around June and July, but it peaks near 7° altitude from 50°N and near 22° from 35°N.
- One imager stacked 56 two-minute unfiltered subs (about 112 minutes) from a modified DSLR on a 130 mm refractor at f/4.9.
- Another imager shot it in LRGB from urban skies with an 8-inch scope at f/5.75; the dense Milky Way star field behind the cloud supplies the contrast.
Facts
- Size
- 12′ × 7′
- Magnitude
- —
- Coordinates
- RA 18h 4.3m, Dec −32° 40′
- Framing, APS-C
- 2020–3370 mm
- Framing, full frame
- 3090–5160 mm
- Best months
- Jun, Jul
- Peak altitude
- 7° from 50°N, 22° from 35°N