Open Cluster NGC 6819

Object Description

NGC 6819
NGC 6819: Open cluster in Cygnus; 500 mm Cassegrain 3625 mm f/7.2; SBIG STL11K; 180+3*40 min LRGB; Bernese Highlands; © 2015 Radek Chromik

History

NGC 6819 was discovered on March 12, 1784 by Caroline Herschel with her 4.2 inch reflector. However, her observations were not mentioned in the publications of her brother William. This is why John L. E. Dreyer knew nothing about it for his «New General Catalogue» in 1888. He indicated as discoverer Karl Ludwig Harding, who observed the star cluster in 1824. [277]

Physical Properties

NGC 6891 is a Trumpler-type I1r open star cluster with an apparent visual magnitude of about seven. The distance is estimated at about 2.4 kpc (about 7800 light years) and the age at 2.4 billion years. The metallicity is about that of the Sun and the mass of the cluster is about 2600 solar masses. [386]

«Revised New General Catalogue and Index Catalogue» Dr. Wolfgang Steinicke, 2021 [277]
DesignationNGC 6819
TypeOCL (I1r)
Right Ascension19h 41m 18.0s
Declination+40° 11' 00"
Diameter5.00 arcmin
Visual magnitude7.3 mag
Dreyer DescriptionCl, vL, vRi, st 11…15
IdentificationOCL 155

Finder Chart

Open star cluster NGC 6819 is located in the constellation of Cygnus. The best viewing time is April to November.

Chart NGC 6819
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

References

149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
386«Linking the rotation of a cluster to the spins of its stars: the kinematics of NGC 6791 and NGC 6819 in 3D» S Kamann, N J Bastian, M Gieles, E Balbinot, V Hénault-Brunet; Monthly Notices of the Royal Astronomical Society, Volume 483, Issue 2, February 2019, Pages 2197–2206; arXiv:1811.08476; DOI:10.1093/mnras/sty3144