M 10 (GC)
Globular Cluster in Ophiuchus
| R.A. | Dec. | Size | Mag | SB | Cnt.St | Type | Distance | Chart |
|---|---|---|---|---|---|---|---|---|
| 16h 57m 10.1s | -04° 06′ 06.9″ | 20.0′ | 6.6 | 12.8 | VII | GC | -- | -- |
Source: POSS-2 UK Schmidt Red (STScI) | Field: 30′ × 30′
Background
M10 is one of the brightest globular clusters in Ophiuchus — magnitude 6.6, 14,300 light-years away. About 11 billion years old. A fairly loose globular, easy to resolve at moderate aperture.
My Observing Notes
25-cm (Club 10-inch LX200): Large with a well-resolved core. Chains of brighter stars streak out from the core; two big chains arc to the top-left and bottom-right, giving the cluster an almost spiral-like shape. A beautiful view.(Saturday, June 2025)
References
Charts
Ultra-wide view (~25° field)
Wide-field view with Telrad rings (4°, 2°, 0.5°)
Finderscope view (9×50 RACI, ~4.4° TFOV)
Eyepiece view — 35 mm Panoptic on 12-inch f/5 (1.6° TFOV)