Owl Nebula

Messier 97, Owl Nebula
Emission nebula
Planetary nebula
Owl Nebula Messier 97
Observation data: J2000.0 epoch
Right ascension11h 14m 47.734s[1]
Declination+55° 01′ 08.50″[1]
Distance2,030 ly (621 pc)[2]
2,800 ly (870 pc)[3] ly
Apparent magnitude (V)9.9[4]
Apparent dimensions (V)3′.4 × 3′.3
ConstellationUrsa Major
Physical characteristics
Radius0.91 ly (0.28 pc)[5] ly
Notable featuresOwl-like "eyes" visible through larger telescopes
DesignationsM97, NGC 3587, PN G148.4+57.0
See also: Lists of nebulae

The Owl Nebula (also known as Messier 97, M97 or NGC 3587) is a planetary nebula approximately 2,030 light years away in the constellation Ursa Major.[2] Estimated to be about 8,000 years old,[6] it is approximately circular in cross-section with a faint 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.[5] 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.[5]

The nebula holds about 0.13 solar masses (M☉) of matter, including hydrogen, helium, nitrogen, oxygen, and sulfur;[5] 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.[5]

The 14th magnitude central star has passed the turning point in its evolution and is condensing to form a white dwarf.[7][8] It has 55–60% of solar mass, is 41 to 148 times solar luminosity (L☉),[5] and has an effective temperature of 123,000 K.[9] 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.[10]

  1. ^ a b Cite error: The named reference Kerber2003 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Stanghellini2008 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Frew-Parker-Bojcic2016 was invoked but never defined (see the help page).
  4. ^ "Messier 97". SEDS Messier Catalog. Retrieved 30 April 2022.
  5. ^ a b c d e f Cite error: The named reference CuestaPhillips2000 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference calc_age was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Guerrero2003 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Jones1991 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Capriotti1968 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Bilikova2012 was invoked but never defined (see the help page).