Cr70 — Orion Belt
Open Cluster in Orion
About
The loose group of hot young stars around Orion's Belt, centred on Alnilam; one source counts more than 100 members. The three belt stars lie about 1,200 to 1,260 light-years away and together span about 2.3°. All three are brighter than magnitude 2.3, and some are multiple systems.
Imaging tips
- At 160–270 mm on APS-C (250–410 mm full frame) the group fits in one frame; the Horsehead Nebula lies about 115′ away, so it is nearby rather than inside a tight crop.
- One 2-hour wide-field image of this area shows the red band of IC 434, the Flame Nebula and the arc of Barnard's Loop beside the belt.
- The cluster is a broadband target; the hydrogen nebulae around it are emission nebulae, so Hα suits them.
- Best in December; it peaks near 39° altitude from 50°N.
Facts
- Size
- 150′
- Magnitude
- 0.4
- Coordinates
- RA 5h 35.5m, Dec −1° 6′
- Framing, APS-C
- 160–270 mm
- Framing, full frame
- 250–410 mm
- Best months
- Dec
- Peak altitude
- 39° from 50°N, 54° from 35°N
Nearby
- B33 (Horsehead Nebula) · 114.9′ away
- vdB52 · 115.4′ away