IC 4651 (OC)
Open Cluster in Ara
| R.A. | Dec. | Size | Mag | SB | Cnt.St | Type | Distance | Chart |
|---|---|---|---|---|---|---|---|---|
| 17h 24m 50.4s | -49° 55′ 52.8″ | 14.0′ | 6.9 | 12.4 | II3m | OC | -- | -- |
Source: POSS-2 UK Schmidt Red (STScI) | Field: 15′ × 15′
Background
IC 4651 is a moderately rich open cluster 3,000 light-years away in Ara. Around 1.5 billion years old — quite old as open clusters go, making it a useful laboratory for studying main-sequence turn-off photometry.
My Observing Notes
25-cm (Meade 10-inch LX200, The Coffee Grinder): 2° from α Ara. In the viewfinder picks up as a hazy patch of stars; in the eyepiece a loose, sparsely populated group almost blending with the surrounding field. Two circular star patterns sit in the centre giving it some structure.(Friday, 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)