Messier 81

For other uses, see M81 (disambiguation).

Messier 81
The HST's view of M81, with its open star clusters, globular star clusters, and regions of fluorescent gas.
Observation data (J2000 epoch)
ConstellationUrsa Major[1]
Right ascension09h 55m 33.2s[2]
Declination+69° 3′ 55″[2]
Redshift−0.000113
Heliocentric radial velocity−34
Galactocentric velocity73
Distance11.8 Mly (3.6 Mpc)
Apparent magnitude (V)6.94[3][4]
Characteristics
TypeSA(s)ab,[2] LINER[2]
Size29.44 kiloparsecs (96,000 light-years)
(diameter; 25.0 mag/arcsec2 B-band isophote)[2][5]
Apparent size (V)26.9 × 14.1 moa[2]
Other designations
NGC 3031, UGC 5318, MCG+12-10-010, PGC 28630, Bode's Galaxy[3]
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Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of 29.44 kiloparsecs (96,000 light-years).[2][5] Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M☉[6] supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy's large size and relatively high brightness also makes it a popular target for amateur astronomers.[7] In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.[8][9]

  1. ^ Dreyer, J. L. E. (1988). Sinnott, R. W. (ed.). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters. Sky Publishing Corporation / Cambridge University Press. ISBN 978-0-933346-51-2.
  2. ^ a b c d e f g h i j "NASA/IPAC Extragalactic Database". Results for Messier 081. Retrieved 6 November 2022.
  3. ^ a b "M 81". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 28 November 2009.
  4. ^ Armando, Gil de Paz; Boissier, Samuel; Madore, Barry F.; Seibert, Mark; Joe, Young H.; Boselli, Alessandro; Wyder, Ted K.; Thilker, David; Bianchi, Luciana; Rey, Soo-Chang; Rich, R. Michael; Barlow, Tom A.; Conrow, Tim; Forster, Karl; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick; Neff, Susan G.; Schiminovich, David; Small, Todd; Donas, José; Heckman, Timothy M.; Lee, Young-Wook; Milliard, Bruno; Szalay, Alex S.; Yi, Sukyoung (2007). "The GALEX Ultraviolet Atlas of Nearby Galaxies". Astrophysical Journal. 173 (2): 185–255. arXiv:astro-ph/0606440. Bibcode:2007ApJS..173..185G. doi:10.1086/516636. S2CID 119085482.
  5. ^ a b De Vaucouleurs, Gerard; De Vaucouleurs, Antoinette; Corwin, Herold G.; Buta, Ronald J.; Paturel, Georges; Fouque, Pascal (1991). Third Reference Catalogue of Bright Galaxies. Bibcode:1991rc3..book.....D.
  6. ^ Devereux, N.; Ford, H.; Tsvetanov, Z.; Jocoby, J. (2003). "STIS Spectroscopy of the Central 10 Parsecs of M81: Evidence for a Massive Black Hole". Astronomical Journal. 125 (3): 1226–1235. Bibcode:2003AJ....125.1226D. doi:10.1086/367595. S2CID 121093306.
  7. ^ O'Meara, S. J. (1998). The Messier Objects. Cambridge University Press. ISBN 978-0-521-55332-2.
  8. ^ Cite error: The named reference SA-20220223 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference NAT-20220223 was invoked but never defined (see the help page).