NGC 5617 (OC)
Open Cluster in Centaurus
| R.A. | Dec. | Size | Mag | SB | Cnt.St | Type | Distance | Chart |
|---|---|---|---|---|---|---|---|---|
| 14h 29m 46.5s | -60° 42′ 46.3″ | 15.0′ | 6.3 | 11.9 | I3r | OC | -- | -- |
Source: POSS-2 UK Schmidt Red (STScI) | Field: 15′ × 15′
Background
NGC 5617 is a small, compact open cluster about 5,500 light-years away in Centaurus, sitting just 1° west-northwest of Rigil Kentaurus (α Cen). Discovered by James Dunlop from his Parramatta observatory in Sydney in 1826, who described it as “a cluster of small stars of mixed magnitudes, considerably congregated towards the centre”. Forms a gravitationally-bound pair with the fainter Trumpler 22 0.5° to the south.
My Observing Notes
25-cm (Meade 10-inch LX200, The Coffee Grinder): Easy to spot in the viewfinder as a bright knot of stars 1° WNW of α Cen. Could pick out a distinctive figure-eight pattern of stars amongst the cluster.(Friday, May 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)