NGC 6522 (GC)

Globular Cluster in Sagittarius
R.A.Dec.SizeMag SBCnt.StTypeDistanceChart
18h 03m 35.0s-30° 02′ 00.3″0′′9.5----GC----
NGC 6522 DSS plate
Source: POSS-2 UK Schmidt Red (STScI) | Field: 10′ × 10′

Background

NGC 6522 is one of two globular clusters within Baade's Window — a famously low-extinction line of sight toward the Galactic Centre. About 25,000 light-years away, it is among the oldest globular clusters known ( 12 billion years).

My Observing Notes

55-cm (Club 22-inch f/5 Lord Sidious): The brighter of the two Baade's Window globulars, observed alongside NGC 6528. The pair of globulars sits in a famously dust-free corridor through the Galactic disc — an observational “window” to the Galactic Centre of the Milky Way.(11 April 2026)

References

Charts

NGC 6522 ultra-wide chart
Ultra-wide view (~25° field)
NGC 6522 wide-field chart
Wide-field view with Telrad rings (4°, 2°, 0.5°)
NGC 6522 finderscope view
Finderscope view (9×50 RACI, ~4.4° TFOV)
NGC 6522 eyepiece view
Eyepiece view — 35 mm Panoptic on 12-inch f/5 (1.6° TFOV)