Globular Clusters NGC 6522 & NGC 6528

NGC 6522 + NGC 6528
NGC 6522 + NGC 6528: Section of the STScI/NASA Digitized Sky Survey 2 (DSS2). Here could be your picture. [147]

History

These two globular clusters were discovered by William Herschel on 24 June 1784. For I 49 (NGC 6522) he noted: «Bright, pretty large, brighter in the middle, resolvable.» For II 200 (NGC 6528) he noted: «Faint, pretty small, resolvable, unequally bright.» [463] John Herschel observed these clusters on 3 August 1834 from South Africa and recorded them as h 3720 (NGC 6522) and h 3723 (NGC 6528). He identified them as globular clusters and noted: «Both this and I 49 occur on a ground so astonishingly rich and stippled over with stars 17 m individually discernible, as hardly to admit a pin's point between the stars, and this fills more than the whole field or many fields.» [11]

Edward. E. Barnard found on photographs he made several irregular dark clouds near clusters NGC 6522 and NGC 6528. After his death in 1923 these were listed as B 295 and B 298 in the «Photographic Atlas of Selected Regions of the Milky Way», published 1927. [609]

Physical Properties

These two globular clusters are located in the bulge of the Milky Way, circa 1 kpc away from the Galactic centre in a region with relatively small amounts of interstellar gas called Baade’s Window.

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
NameRADecTypevMagDimMDDreyer DescriptionIdentification, Remarks
NGC 652218 03 34.1-30 02 00GCL (VI)9.99.47.700globular, B, pL, R, gvmbM, rrr, st 16WH I 49; h 3720; GC 4359; GCL 82; ESO 456-SC43
NGC 652818 04 49.6-30 03 19GCL (V)9.657.900globular, pF, cS, R, gbM, rrr, st 16WH II 200; h 3723; GC 4364; GCL 84; ESO 456-SC48

Finder Chart

The globular clusters NGC 6522 and NGC 6528 are located in the constellation Sagittarius. They are on 23 June in opposition to the Sun. From your location it can best be seen in the months May to November.

Sagittarius: Globular Clusters NGC 6522 & NGC 6528
Finder Chart Globular Clusters NGC 6522 & NGC 6528
19:55
22:38 | 13.2°
01:21
Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. Times are shown for timezone UTC, Latitude 46.7996°, Longitude 8.23225°, Horizon height 5°, Date 2025-07-06. [149, 160]

Objects Within a Radius of 10°

References

  • [11] Results of astronomical observations made during the years 1834, 5, 6, 7, 8, at the Cape of Good Hope ... : being the completion of a telescopic survey of the whole surface of the visible heavens, commenced in 1825; Herschel, John F. W.; London: published by Smith, Elder and Co., 1847; DOI:10.3931/e-rara-22242
  • [147] Aladin Sky Atlas, Centre de Données astronomiques de Strasbourg (CDS); aladin.unistra.fr
  • [149] SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
  • [160] The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
  • [277] Historische Deep-Sky Kataloge; Dr. Wolfgang Steinicke; klima-luft.de/steinicke; 2021-02-17
  • [463] Catalogue of one thousand new nebulae and clusters of stars; William Herschel; Philosophical Transactions of the Royal Society of London, 1 January 1786; DOI:10.1098/rstl.1786.0027
  • [609] A Photographic Atlas of Selected Regions of the Milky Way; Edward Emerson Barnard; 1927; exhibit-archive.library.gatech.edu/barnard/index.html; 2023-05-05