Cr302
Open Cluster in Scorpius
About
A very wide, sparse stellar group in Scorpius that SIMBAD lists as a moving group about 189′ across. From its parallax of 2.36 mas it lies about 1,400 light-years away. Its catalogue centre falls about 0.5′ from the globular cluster M4, but M4 is a separate, much farther object.
Imaging tips
- At about 189′ (over 3°) it needs a wide lens or a large mosaic.
- M4 sits almost at its centre on the sky, but SIMBAD's parallax of 0.556 mas puts M4 near 5,900 light-years, so treat the two as separate targets.
- Broadband is the right choice for a star group; the stars are the subject.
- Best in May and June; it stays below 14° altitude from 50°N.
Facts
- Size
- 189′
- Magnitude
- 7.8
- Coordinates
- RA 16h 23.6m, Dec −26° 31′
- Framing, APS-C
- 130–210 mm
- Framing, full frame
- 200–330 mm
- Best months
- May, Jun
- Peak altitude
- 14° from 50°N, 29° from 35°N