M 55 (GC)
Globular Cluster in Sagittarius
| R.A. | Dec. | Size | Mag | SB | Cnt.St | Type | Distance | Chart |
|---|---|---|---|---|---|---|---|---|
| 19h 40m 00.0s | -30° 57′ 49.1″ | 19.0′ | 6.3 | 12.4 | XI | GC | -- | -- |
Source: POSS-2 UK Schmidt Red (STScI) | Field: 15′ × 15′
Background
M55 is a large, loose globular cluster 17,600 light-years away in Sagittarius, 19' across. Notable for its low central concentration and high resolvability — most of its stars can be picked out with moderate aperture.
My Observing Notes
25-cm (Meade 10-inch LX200, The Coffee Grinder): Sits below the “Teapot”. Large ( 19') but with relatively low surface brightness. Begin to resolve stars across the cluster — a lovely view compared to the unresolved globulars elsewhere in Sagittarius.(Saturday, June 2025)
44-cm (Club 17.5-inch f/5): Revisited from the previous month with the larger Club aperture and low-power eyepiece — really impressive at this aperture.(Saturday, September 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)