NGC 721 is a barred spiral galaxy located in the constellation Andromeda about 250 million light years from the Milky Way. It was discovered by the Prussian astronomer Heinrich d'Arrest in 1862.[5][6][7]

See also

References

  1. ^ a b Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
  2. ^ a b c d "NGC 721". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-05-20.
  3. ^ Tully, R. Brent; Courtois, Hélène M.; Sorce, Jenny G. (2016). "Cosmicflows-3". The Astronomical Journal. 152 (2): 21. arXiv:1605.01765. Bibcode:2016AJ....152...50T. doi:10.3847/0004-6256/152/2/50. S2CID 250737862. 50.
  4. ^ "Results for object NGC 0721 (NGC 721)". NASA/IPAC Extragalactic Database. California Institute of Technology. Retrieved 2020-05-24.
  5. ^ Ford, Dominic. "The galaxy NGC 721 - In-The-Sky.org". in-the-sky.org. Retrieved 2020-04-09.
  6. ^ "Revised NGC Data for NGC 721". spider.seds.org. Retrieved 2020-04-09.
  7. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2020-04-09.