NGC 6520 (OC)
Open Cluster in Sagittarius
| R.A. | Dec. | Size | Mag | SB | Cnt.St | Type | Distance | Chart |
|---|---|---|---|---|---|---|---|---|
| 18h 03m 24.9s | -27° 53′ 15.4″ | 5.0′ | 7.6 | 10.8 | I2rn | OC | -- | -- |
Source: POSS-2 UK Schmidt Red (STScI) | Field: 15′ × 15′
Background
NGC 6520 is a young ( 190 Myr), compact open cluster about 6,000 light-years away in Sagittarius. Spectacularly paired with the dark nebula Barnard 86 (the “Black Droplet”) just to its west — the contrast of bright cluster and inky absorption gives it the nickname “Deadman's Treasure”.
My Observing Notes
55-cm (Club 22-inch f/5 Lord Sidious): Suggested by Michael, a visiting observer from Melbourne. Swung down to the eastern sky once Sagittarius had cleared the trees — and was not disappointed. The cluster itself is rich and compact, with a circle of stars surrounding an inner star. Adjacent and unmistakable is Barnard 86, a striking dark nebula. Nearby sit the Baade's Window globular pair, NGC 6522 and NGC 6528.(11 April 2026)
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)