World Library  
Flag as Inappropriate
Email this Article
 

Owl Nebula

Messier 97, Owl Nebula
Owl Nebula
Observation data
(Epoch J2000.0)
Right ascension 11h 14m 47.734s[1]
Declination +55° 01′ 08.50″[1]
Distance 2,030 ly (621 pc)[2]
Apparent magnitude (V) +9.9
Apparent dimensions (V) 3′.4 × 3′.3
Constellation Ursa Major
Physical characteristics
Radius 0.91 ly (0.28 pc)[3]
Notable features Owl-like "eyes" visible through larger telescopes
Other designations M97, NGC 3587, PN G148.4+57.0

The Owl Nebula (Messier 97,M97, NGC 3587) is a planetary nebula located approximately 2,030 light years away in the constellation Ursa Major.[2] It was discovered by French astronomer Pierre Méchain on February 16, 1781.[4] When William Parsons, 3rd Earl of Rosse, observed the nebula in 1848, his hand-drawn illustration resembled an owl's head. It has been known as the Owl Nebula ever since.[5]

The nebula is approximately 8,000 years old.[6] It is approximately circular in cross-section with a little visible internal structure. It was formed from the outflow of material from the stellar wind of the central star as it evolved along the asymptotic giant branch.[3] The nebula is arranged in three concentric shells, with the outermost shell being about 20–30% larger than the inner shell.[7] The owl-like appearance of the nebula is the result of an inner shell that is not circularly symmetric, but instead forms a barrel-like structure aligned at an angle of 45° to the line of sight.[3]

The nebula holds about 0.13 solar masses of matter, including hydrogen, helium, nitrogen, oxygen, and sulfur;[3] all with a density of less than 100 particles per cubic centimeter.[7] Its outer radius is around 0.91 ly (0.28 pc) and it is expanding with velocities in the range of 27–39 km/s into the surrounding interstellar medium.[3]

The 14th magnitude central star has since reached the turning point of its evolution where it condenses to form a white dwarf.[4][7] It has 55–60% of the Sun's mass, 41–148 times the brightness of the Sun,[3] and an effective temperature of 123,000 K.[8] The star has been successfully resolved by the Spitzer Space Telescope as a point source that does not show the infrared excess characteristic of a circumstellar disk.[9]

See also

References

  1. ^ a b Kerber, F.; et al. (September 2003), "Galactic Planetary Nebulae and their central stars. I. An accurate and homogeneous set of coordinates", Astronomy and Astrophysics 408: 1029–1035,  
  2. ^ a b Stanghellini, Letizia; et al. (December 2008), "The Magellanic Cloud Calibration of the Galactic Planetary Nebula Distance Scale", The Astrophysical Journal 689 (1): 194–202,  
  3. ^ a b c d e f Cuesta, L.; Phillips, J. P. (November 2000), "Excitation and Density Mapping of NGC 3587", The Astrophysical Journal 120 (5): 2661–2669,  
  4. ^ a b Jones, Kenneth Glyn (1991), Messierś Nebulae and Star Clusters (2nd ed.), Cambridge University Press, pp. 277–279,  
  5. ^ Clark, Roger Nelson (1990), Visual Astronomy of the Deep Sky, CUP Archive, p. 133,  
  6. ^ Per Guerrero et al. (2003), the age is 12,900 × d years, where d is the distance in kpc. According to Stanghellini et al. (2008), d is 0.621 kpc. Hence, the age is 12,900 × 0.621 ≈ 8,000 years.
  7. ^ a b c Guerrero, Martín A.; et al. (June 2003), "Physical Structure of Planetary Nebulae. I. The Owl Nebula", The Astrophysical Journal 125 (6): 3213–3221,  
  8. ^ Capriotti, Eugene R.; Kovach, William S. (March 1968), "Effective Temperatures of the Central Stars of Planetary Nebulae", Astrophysical Journal 151 (5): 991–995,  
  9. ^ Bilíková, Jana; et al. (May 2012), "Spitzer Search for Dust Disks around Central Stars of Planetary Nebulae", The Astrophysical Journal Supplement 200 (1): 3,  

External links

  • The Owl Nebula @ SEDS Messier pages
  • The Owl Nebula at Calar Alto Observatory
  • NightSkyInfo.com – M97, the Owl Nebula
  • The Owl Nebula on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
  • Norton, Andy; Crowther, Paul; Hardy, Liam. "M97 – Owl Nebula". Deep Space Videos.  
  • The Owl Nebula (M97) at Constellation Guide

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.