Open Cluster NGC 188


This open cluster was discovered on 3 November 1831 by John Herschel using his 18.3 inch reflecting telescope. He cataloged it with the number h 34 in his «Slough Catalogue» and noted: «Cluster, very large, pretty rich 150...200 stars 10...8m; more than fills the field» [466] Dreyer added it 1888 as NGC 188 to his «New General Catalogue». [313]

In 1995 this cluster was added by the British astronomer Sir Patrick Moore as first and northernmost object C 1 in his Caldwell Catalogue. [299]

Physical Properties

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
Designation NGC 188
Type OCL (II2r)
Right Ascension (J2000.0) 00h 47m 30.0s
Declination (J2000.0) +85° 15' 30"
Diameter 15 arcmin
Visual magnitude 8.1 mag
Metric Distance 2.000 kpc
Dreyer Description Cl, vL, R, 150-200 st 10…18
Identification, Remarks h 34; GC 92; OCL 309

Finder Chart

The open cluster NGC 1888 can be found in the constellation Ursa Minor, circa 4° away from the pole star and hence visible all year long in Europe.

Finder Chart Open Cluster NGC 188
Open Cluster NGC 188 in constellation Ursa Minor. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°


  • [149] SkySafari 6 Pro, Simulation Curriculum;
  • [160] The STScI Digitized Sky Survey;
  • [277] «Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; (2021-02-17)
  • [299] «Beyond Messier: The Caldwell Catalog», Patrick Moore; Sky and Telescope, December 1995, page 38; (2023-11-11)
  • [313] «A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged» Dreyer, J. L. E. (1888); Memoirs of the Royal Astronomical Society. 49: 1–237; Bibcode:1888MmRAS..49....1D
  • [466] «Observations of nebulæ and clusters of stars, made at Slough, with a twenty-feet reflector, between the years 1825 and 1833» John Frederick William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1833, Pages: 359-505; DOI:10.1098/rstl.1833.0021