NGC 5822 (OC)

Open Cluster in Lupus
R.A.Dec.SizeMag SBCnt.StTypeDistanceChart
15h 04m 30.5s-54° 23′ 25.4″40.0′6.514.2II2rOC----
NGC 5822 DSS plate
Source: POSS-2 UK Schmidt Red (STScI) | Field: 60′ × 60′

Background

NGC 5822 is a large, sparse open cluster  2,500 light-years away in Lupus,  35' across. About 800 million years old with  150 known members spread broadly across the field — close to its tidal disruption limit.

My Observing Notes

25-cm (Meade 10-inch LX200, The Coffee Grinder): Telrad outer edge on β Lup; the cluster fills the entire FOV of the 35 mm. A bright (mag 6.5) sparse but uniform concentration of 150+ stars. Panning the telescope around the edges helps to distinguish it from the background field. Would benefit from an even wider eyepiece.(Saturday, August 2025)

References

Charts

NGC 5822 ultra-wide chart
Ultra-wide view (~25° field)
NGC 5822 wide-field chart
Wide-field view with Telrad rings (4°, 2°, 0.5°)
NGC 5822 finderscope view
Finderscope view (9×50 RACI, ~4.4° TFOV)
NGC 5822 eyepiece view
Eyepiece view — 35 mm Panoptic on 12-inch f/5 (1.6° TFOV)