Astronomy:NGC 2841

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NGC 2841
NGC 2841 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationUrsa Major
Right ascension 09h 22m 02.655s[1]
Declination+50° 58′ 35.32″[1]
Redshift0.002130[2]
Helio radial velocity638 km/s[3]
Distance46.0 ± 4.9 Mly (14.1 ± 1.5 Mpc)[4][5]
Apparent magnitude (V)10.1[3]
Characteristics
TypeSAa[2]
Mass7×1010 M[6] M
Size~150,000 ly (~46 kpc)
Apparent size (V)8.1 × 3.5[6]
Notable featuresFlocculent galaxy with LINER nucleus
Other designations
IRAS 09185+5111, UGC 4966, MCG+09-16-005, PGC 26512[3]

NGC 2841 is an unbarred spiral galaxy in the northern circumpolar constellation of Ursa Major. It was discovered on 9 March, 1788 by German-born astronomer William Herschel. J. L. E. Dreyer, the author of the New General Catalogue, described it as, "very bright, large, very much extended 151°, very suddenly much brighter middle equal to 10th magnitude star".[7] Initially thought to be about 30 million light-years distant, a 2001 Hubble Space Telescope survey of the galaxy's Cepheid variables determined its distance to be approximately 14.1 megaparsecs, or 46 million light-years.[4] The optical size of the galaxy is 8.1 × 3.5.[6]

This is the prototype for the flocculent spiral galaxy,[5] a type of spiral galaxy whose arms are patchy and discontinuous.[8] The morphological class is SAa, indicating a spiral galaxy with no central bar and very tightly-wound arms. There is no grand design structure visible in the optical band, although some inner spiral arms can be seen in the near infrared.[5] It is inclined by an angle of 68° to the line of sight from the Earth, with the major axis aligned along a position angle of 148°.[5]

Wide field view of the galaxy

The properties of NGC 2841 are similar to those of the Andromeda Galaxy.[4] It is home to a large population of young blue stars, and a few H II regions.[9] The luminosity of the galaxy is 2×1010 L and it has a combined mass of 7×1010 M.[6] Its disk of stars can be traced out to a radius of around 228 kly (70 kpc). This disk begins to warp at a radius of around 98 kly (30 kpc), suggesting the perturbing effect of in-falling matter from the surrounding medium.[5]

The rotational behavior of the galaxy suggests there is a massive nuclear bulge,[6] with a low-ionization nuclear emission-line region (LINER) at the core; a type of region that is characterized by spectral line emission from weakly ionized atoms.[10] A prominent molecular ring is orbiting at a radius of 7–20 kly (2–6 kpc), which is providing a star-forming region of gas and dust.[6] The nucleus appears decoupled and there is a counter-rotating element of stars and gas in the outer parts of the nucleus, suggesting a recent interaction with a smaller galaxy.[6]

Supernovae

Four supernovae have been observed in NGC 2841.

  • SN 1912A (Type Ia, mag. 13) was discovered by Heber Curtis and Francis Pease on 19 February 1912.[11][12]
  • SN 1957A (Type Ia-pec, mag. 14) was discovered by Max Schürer on 1 March 1957.[13][14] [Note: some sources incorrectly list the discovery date as 26 February 1957.]
  • SN 1972R (type unknown, mag. 16) was discovered by Paul Wild on 5 December 1972.[15]
  • SN 1999by (Type Ia-pec, mag. 15) was codiscovered by Ron Arbour, and the Lick Observatory Supernova Search, on 30 April 1999.[16][17]

See also

References

  1. 1.0 1.1 Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W. et al. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal 131 (2): 1163–1183. doi:10.1086/498708. ISSN 0004-6256. Bibcode2006AJ....131.1163S. 
  2. 2.0 2.1 Ann, H. B. et al. (2015). "A Catalog of Visually Classified Galaxies in the Local (z ~ 0.01) Universe". The Astrophysical Journal Supplement Series 217 (2): 27. doi:10.1088/0067-0049/217/2/27. Bibcode2015ApJS..217...27A. 
  3. 3.0 3.1 3.2 "NASA/IPAC Extragalactic Database". Results for NGC 2841. http://nedwww.ipac.caltech.edu/. Retrieved 2006-10-04. 
  4. 4.0 4.1 4.2 Macri, L. M.; Stetson, P. B.; Bothun, G. D.; Freedman, W. L. et al. (September 2001). "The Discovery of Cepheids and a New Distance to NGC 2841 Using the Hubble Space Telescope". Astrophysical Journal 559 (1): 243–259. doi:10.1086/322395. ISSN 0004-637X. Bibcode2001ApJ...559..243M. 
  5. 5.0 5.1 5.2 5.3 5.4 Zhang, Jielai et al. (March 2018). "The Dragonfly Nearby Galaxies Survey. IV. A Giant Stellar Disk in NGC 2841". The Astrophysical Journal 855 (2): 8. doi:10.3847/1538-4357/aaac81. 78. Bibcode2018ApJ...855...78Z. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Kaneda, H. et al. (October 2007). "Far-Infrared Distributions in Nearby Spiral Galaxies NGC 2841 and NGC 2976 Observed with AKARI/Far-Infrared Surveyor (FIS)". Publications of the Astronomical Society of Japan 59 (s2): S463. doi:10.1093/pasj/59.sp2.S463. Bibcode2007PASJ...59S.463K. 
  7. Seligman, Courtney. "NGC Objects: NGC 2800 - 2849". Celestial Atlas. http://cseligman.com/text/atlas/ngc28.htm#2841. Retrieved 2016-03-01. 
  8. A Near-Infrared Atlas of Spiral Galaxies. http://nedwww.ipac.caltech.edu/level5/Elmegreen/Elm3.html. Retrieved 23 April 2010.  See CH3. Discussion.
  9. Marochnik, Leonid; Suchkov, Anatoly (1995-11-01). Milky Way Galaxy (1st ed.). Routledge. p. 267. ISBN 978-2-88124-931-0. 
  10. Ho, L. C. et al. (1997). "A Search for "Dwarf" Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies". Astrophysical Journal Supplement 112 (2): 315–390. doi:10.1086/313041. Bibcode1997ApJS..112..315H. 
  11. Pease, F. G. (1917). "A Suspected Nova in the Nebula N. G. C. 2841". Publications of the Astronomical Society of the Pacific 29 (171): 213. doi:10.1086/122639. Bibcode1917PASP...29..213P. 
  12. "SN 1912A". IAU. https://www.wis-tns.org/object/1912A. 
  13. Hansen, Julie M. Vinter (6 March 1957). "Circular No. 1588". Observatory Copenhagen. http://www.cbat.eps.harvard.edu/IAUCs/IAUC1588.jpg. 
  14. "SN 1957A". IAU. https://www.wis-tns.org/object/1957A. 
  15. "SN 1972R". IAU. https://www.wis-tns.org/object/1972R. 
  16. Arbour, R.; Papenkova, M.; Li, W. D.; Filippenko, A. V.; Armstrong, M. (1999). "Supernova 1999by in NGC 2841". International Astronomical Union Circular (7156): 1. Bibcode1999IAUC.7156....1A. 
  17. "SN 1999by". IAU. https://www.wis-tns.org/object/1999by. 

Coordinates: Sky map 9h 22m 02.6s, +50° 58′ 35″