Messier 81
![Sky map](http://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Jupiter_and_moon.png/20px-Jupiter_and_moon.png)
moa[2] | |
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Other designations | |
NGC 3031, UGC 5318, MCG+12-10-010, PGC 28630, Bode's Galaxy[3] |
Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a
Discovery
Messier 81 was first discovered by Johann Elert Bode on 31 December 1774.[10] Thus, it is sometimes referred to as "Bode's Galaxy". In 1779, Pierre Méchain and Charles Messier reidentified Bode's object, hence listed it in the Messier Catalogue.[10]
Visibility
The galaxy is to be found approximately 10° northwest of
Messier 81 and Messier 82 are considered ideal for viewing using binoculars and small telescopes.[7][11] The two objects are generally not observable to the unaided eye, although highly experienced amateur astronomers may be able to see Messier 81 under exceptional observing conditions with a very dark sky.[7][12] Telescopes with apertures of 8 inches (20 cm) or larger are needed to distinguish structures in the galaxy.[11]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Messier81_highres.jpg/220px-Messier81_highres.jpg)
The galaxy is best observed during April. [15]
Interstellar dust
Most of the emission at infrared wavelengths originates from
Globular clusters
It is estimated M81 has 210 ± 30 globular clusters.[17] In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.[8][9]
Supernovae
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/AnttlersM81M82.jpg/220px-AnttlersM81M82.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/M81.jpg/220px-M81.jpg)
Only one supernova has been detected in Messier 81.[18] The supernova, named SN 1993J, was discovered on 28 March 1993 by F. García in Spain.[19] At the time, it was the second brightest supernova observed in the 20th century,[20] peaking at an apparent magnitude of 10.7. The spectral characteristics of the supernova changed over time. Initially, it looked more like a type II supernova (a supernova formed by the explosion of a supergiant star) with strong hydrogen spectral line emission, but later the hydrogen lines faded and strong helium spectral lines appeared, making the supernova look more like a type Ib.[20][21]
Moreover, the variations in SN 1993J's luminosity over time were not like the variations observed in other type II supernovae,
Environment
Messier 81 is the largest galaxy in the M81 Group, a group of 34 in the constellation Ursa Major.[27] At approximately 11.7 Mly (3.6 Mpc) from the Earth, it makes this group and the Local Group, containing the Milky Way,[27] relative neighbors in the Virgo Supercluster.
Gravitational interactions of M81 with M82 and NGC 3077[28] have stripped hydrogen gas away from all three galaxies, forming gaseous filamentary structures in the group.[28] Moreover, these interactions have allowed interstellar gas to fall into the centers of M82 and NGC 3077, leading to vigorous star formation or starburst activity there.[28]
Distance
The distance to Messier 81 has been measured by Freedman et al
See also
- List of galaxies
- List of Messier objects
- Messier object
- New General Catalogue
References
- ^
Dreyer, J. L. E. (1988). Sinnott, R. W. (ed.). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters. ISBN 978-0-933346-51-2.
- ^ a b c d e f g h i j "NASA/IPAC Extragalactic Database". Results for Messier 081. Retrieved 6 November 2022.
- ^ a b "M 81". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 28 November 2009.
- ^
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". S2CID 119085482.
- ^ Bibcode:1991rc3..book.....D.
- ^
Devereux, N.; Ford, H.; Tsvetanov, Z.; Jocoby, J. (2003). "STIS Spectroscopy of the Central 10 Parsecs of M81: Evidence for a Massive Black Hole". S2CID 121093306.
- ^ a b c d
O'Meara, S. J. (1998). The Messier Objects. ISBN 978-0-521-55332-2.
- ^ a b Starr, Michelle (23 February 2022). "Mysterious Repeating Fast Radio Burst Traced to Very Unexpected Location". ScienceAlert. Retrieved 24 February 2022.
- ^ S2CID 235166402. Retrieved 24 February 2022.
- ^ a b
Jones, K. G. (1991). Messier's Nebulae and Star Clusters (2nd ed.). ISBN 978-0-521-37079-0.
- ^ a b c
Eicher, D. J. (1988). The Universe from Your Backyard. ISBN 978-0-521-36299-3.
- ^ Stephen Uitti. "Farthest Naked Eye Object". Archived from the original on 19 August 2008. Retrieved 1 November 2008.
- ^ a b
Willner, S. P.; Ashby, M. L. N.; Barmby, P.; Fazio, G. G.; Pahre, M.; Smith, H. A.; Kennicutt Jr., R. C.; S2CID 16609000.
- ^ a b c
Gordon, K. D.; Pérez-González, P. G.; Misselt, K. A.; Murphy, E. J.; Bendo, G. J.; Walter, F.; Thornley, M. D.; Kennicutt Jr., R. C.; Rieke, G. H.; Engelbracht, C. W.; Smith, J.-D. T.; S2CID 17283721.
- ^ https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-81/
- ^ a b
Pérez-González, P. G.; Kennicutt Jr., R. C.; Gordon, K. D.; Misselt, K. A.; Gil De Paz, A.; Engelbracht, C. W.; Rieke, G. H.; Bendo, G. J.; Bianchi, L.; Boissier, S.; Calzetti, D.; Dale, D. A.; Draine, B. T.; Jarrett, T. H.; Hollenbach, D.; Prescott, M. K. M. (2006). "Ultraviolet through Far-Infrared Spatially Resolved Analysis of the Recent Star Formation in M81 (NGC 3031)". S2CID 13901458.
- ISSN 0004-637X.
- ^ "NASA/IPAC Extragalactic Database". Results for extended name search on NGC 3031. Retrieved 27 February 2007.
- ^
Ripero, J.; Garcia, F.; Rodriguez, D.; Pujol, P.; Filippenko, A. V.; Treffers, R. R.; Paik, Y.; Davis, M.; Schlegel, D.; Hartwick, F. D. A.; Balam, D. D.; Zurek, D.; Robb, R. M.; Garnavich, P.; Hong, B. A. (1993). "Supernova 1993J in NGC 3031". Bibcode:1993IAUC.5731....1R.
- ^ a b c
Schmidt, B.P.; Kirshner, R.P.; Eastman, R.G.; Grashuis, R.; Dell'Antonio, I.; Caldwell, N.; Foltz, C.; Huchra, John P.; Milone, Alejandra A. E. (1993). "The unusual supernova SN1993J in the galaxy M81". S2CID 4304547.
- ^ a b c
Filippenko, A. V.; Matheson, T.; Ho, L. C. (1993). "The "Type IIb" Supernova 1993J in M81: A Close Relative of Type Ib Supernovae". doi:10.1086/187043.
- ^
Benson, P. J.; Herbst, W.; Salzer, J. J.; Vinton, G.; Hanson, G. J.; Ratcliff, S. J.; Winkler, P. F.; Elmegreen, D. M.; Chromey, F.; Strom, C.; Balonek, T. J.; Elmegreen, B. G. (1994). "Light curves of SN 1993J from the Keck Northeast Astronomy Consortium". doi:10.1086/116958.
- ^
Wheeler, J. C.; Barker, E.; Benjamin, R.; Boisseau, J.; Clocchiatti, A.; De Vaucouleurs, G.; Gaffney, N.; Harkness, R. P.; Khokhlov, A. M.; Lester, D. F.; Smith, B. J.; Smith, V. V.; Tomkin, J. (1993). "Early Observations of SN 1993J in M81 at McDonald Observatory". doi:10.1086/187097.
- ^
Richmond, M. W.; Treffers, R. R.; Filippenko, A. V.; Palik, Y.; Leibundgut, B.; Schulman, E.; Cox, C. V. (1994). "UBVRI photometry of SN 1993J in M81: The first 120 days". doi:10.1086/116915.
- ^
Filippenko, A. V.; Matheson, T.; Barth, A. J. (1994). "The peculiar type II supernova 1993J in M81: Transition to the nebular phase". doi:10.1086/117234.
- ^ Bishop, David. "Extragalactic Novae". supernovae.net (International Supernovae Network). Archived from the original on 8 April 2010. Retrieved 11 September 2010.
- ^ a b
Karachentsev, I. D. (2005). "The Local Group and Other Neighboring Galaxy Groups". S2CID 119385141.
- ^ a b c
Yun, M. S.; Ho, P. T. P.; Lo, K. Y. (1994). "A high-resolution image of atomic hydrogen in the M81 group of galaxies". S2CID 4369085.
- doi:10.1086/174172– via Astrophysics Data System.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- StarDate: M81 Fact Sheet
- M81, SEDS Messier pages
- SST: Messier 81
- NASA Astronomy Picture of the Day: Bright Galaxy M81 (20 June 2002)
- NightSkyInfo.com – M81, Bode's Galaxy
- Messier 81 on
- ESA/Hubble images of M81
- Galaxy Messier 81 (Bode's Galaxy)
- Spitzer Image Gallery
- Helkit Observatory
- Deep image of the M81 Area
- Bode's Galaxy at Constellation Guide