NGC 821 explained

NGC 821 is an elliptical galaxy in the constellation Aries. It is estimated to be about 80 million light-years from the Milky Way^[2] and has a diameter of approximately 55,000 light years. NGC 821 was discovered on September 4, 1786, by astronomer Wilhelm Herschel.^[4] ^[5] ^[6]

References

10.1086/498708 . Skrutskie . Michael F. . Cutri . Roc M. . Stiening . Rae . Weinberg . Martin D. . Schneider . Stephen E. . Carpenter . John M. . Beichman . Charles A. . Capps . Richard W. . Chester . Thomas . Elias . Jonathan H. . Huchra . John P. . Liebert . James W. . Lonsdale . Carol J. . Monet . David G. . Price . Stephan . Seitzer . Patrick . Jarrett . Thomas H. . Kirkpatrick . J. Davy . Gizis . John E. . Howard . Elizabeth V. . Evans . Tracey E. . Fowler . John W. . Fullmer . Linda . Hurt . Robert L. . Light . Robert M. . Kopan . Eugene L. . Marsh . Kenneth A. . McCallon . Howard L. . Tam . Robert . Van Dyk . Schuyler D. . Wheelock . Sherry L. . The Two Micron All Sky Survey (2MASS) . The Astronomical Journal . 1 February 2006 . 131 . 2 . 1163–1183 . 2006AJ....131.1163S . 18913331 . 0004-6256 . free .
2016AJ....152...50T. 10.3847/0004-6256/152/2/50. 1605.01765. Cosmicflows-3. Tully, R. Brent. Courtois, Hélène M.. Sorce, Jenny G.. The Astronomical Journal. 152. 2. 50. 21. 2016. 250737862 . free .
NGC 821. 2020-05-24.
Web site: The galaxy NGC 821 - In-The-Sky.org. Ford. Dominic. in-the-sky.org. en. 2020-03-28.
Web site: Revised NGC Data for NGC 821. spider.seds.org. 2020-03-28.
Web site: Your NED Search Results. ned.ipac.caltech.edu. 2020-03-28.