M 12 (GC)

Globular Cluster in Ophiuchus
R.A.Dec.SizeMag SBCnt.StTypeDistanceChart
16h 47m 15.2s-01° 57′ 01.0″16.0′6.111.9IXGC----
M 12 DSS plate
Source: POSS-2 UK Schmidt Red (STScI) | Field: 15′ × 15′

Background

M12 is a moderately bright globular cluster  16,000 light-years away in Ophiuchus, sitting just 3° from the brighter M10. Notable for its relatively loose, irregular core compared to most globulars of its size.

My Observing Notes

25-cm (Club 10-inch LX200): Similar brightness and size to M10. The brighter stars are well resolved. What differentiates this globular is its shape — more irregular ragged edges compared to the symmetry of M10. Averted vision begins to resolve stars in the core.(Saturday, June 2025)

References

Charts

M 12 ultra-wide chart
Ultra-wide view (~25° field)
M 12 wide-field chart
Wide-field view with Telrad rings (4°, 2°, 0.5°)
M 12 finderscope view
Finderscope view (9×50 RACI, ~4.4° TFOV)
M 12 eyepiece view
Eyepiece view — 35 mm Panoptic on 12-inch f/5 (1.6° TFOV)