Messier 81

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Messier 81[1][2]
Messier 81 HST.jpg
A Hubble Space Telescope (HST) image
o Messier 81
Observation data
Epoch J2000
Constellation Ursa Major[3]
Richt ascension 09h 55m 33.2s[4]
Declination +69° 3′ 55″[4]
Apparent dimension (V) 26.9 × 14.1 moa[4]
Apparent magnitude (V) 6.94[5][6]
Characteristics
Type SA(s)ab,[4] LINER[4]
Astrometry
Helio Radial velocity -34 ± 4[4]km/s
Reidshift -0.000113 ± 0.000013[4]
Galactocentric Velocity 73 ± 6[4] km/s
Distance 11.8 ± 0.4 Mly (3.62 ± 0.12 Mpc)
Other designations
NGC 3031,[4] UGC 5318,[4] PGC 28630,[4] Bode's Galaxy[7]

Messier 81 (an aa kent as NGC 3031 or Bode's Galaxy) is a spiral galaxy aboot 12 million licht-years away in the constellation Ursa Major. Due tae its proximity tae Yird, lairge size an active galactic nucleus (which harbors a 70 million M[8] supermassive black hole), Messier 81 haes been studied extensively bi professional astronomers. The galaxy's lairge size an relatively heicj brightness an aa mak it a popular target for amateur astronomers.[9]

References[eedit | eedit soorce]

  1. Jensen, Joseph B.; Tonry, John L.; Barris, Brian J.; Thompson, Rodger I.; Liu, Michael C.; Rieke, Marcia J.; Ajhar, Edward A.; Blakeslee, John P. (2003). "Measuring Distances and Probing the Unresolved Stellar Populations of Galaxies Using Infrared Surface Brightness Fluctuations". Astrophysical Journal. 583 (2): 712–726. arXiv:astro-ph/0210129Freely accessible. Bibcode:2003ApJ...583..712J. doi:10.1086/345430. 
  2. I. D. Karachentsev, O. G. Kashibadze (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics. 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. 
  3. R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation / Cambridge University Press. ISBN 0-933346-51-4. 
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 "NASA/IPAC Extragalactic Database". Results for NGC 3031. Retrieved 2006-11-10. 
  5. "SIMBAD-M81". SIMBAD Astronomical Database. Retrieved 2009-11-28. 
  6. Armando, Gil de Paz; Boissier; Madore; Seibert; Boselli; et al. (2007). "The GALEX Ultraviolet Atlas of Nearby Galaxies". Astrophysical Journal. 173 (2): 185–255. arXiv:astro-ph/0606440Freely accessible. Bibcode:2007ApJS..173..185G. doi:10.1086/516636. 
  7. "SIMBAD Astronomical Database". Results for NGC 3031. Retrieved 2006-11-10. 
  8. N. Devereux, H. Ford, Z. Tsvetanov, and J. Jocoby (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. 
  9. S. J. O'Meara (1998). The Messier Objects. Cambridge University Press. ISBN 0-521-55332-6.