Messier 79

Messier 79
Observation data (J2000 epoch)
ClassV[1]
ConstellationLepus
Right ascension05h 24m 10.59s[2]
Declination−24° 31′ 27.3″[2]
Distance12.9 kpc (42 kly)[3]
Apparent magnitude (V)7.7[4]
Apparent dimensions (V)8.7'
Physical characteristics
Radius53 ly[5]
Metallicity = –1.55[6] dex
Estimated age11.7 Gyr[6]
Other designationsM79, NGC 1904, GCl 10, Melotte 34[2]
See also: Globular cluster, List of globular clusters

Messier 79 (also known as M79 or NGC 1904) is a globular cluster in the southern constellation Lepus. It was discovered by Pierre Méchain in 1780 and is about 42,000 light-years away from Earth and 60,000 light years from the Galactic Center. It is known by Fordingbridge Astronomers as the "Broken Biscuit" cluster after they missed seeing it during a Messier Challenge because they took a coffee break, with biscuits.

Like Messier 54 (the other extragalactic globular on Messier's list), it is believed to not be native to the Milky Way galaxy at all, but instead to the putative Canis Major Dwarf Galaxy, which is currently experiencing a very close encounter with our galaxy. This is, however, a contentious subject as astronomers are still debating the nature of the Canis Major dwarf galaxy itself.[7] Messier 79 may also be part of the Gaia Sausage.[8]

The cluster is being disrupted by the galactic tide, trailing a long tidal tail.[9]

  1. ^ Cite error: The named reference hcob849_11 was invoked but never defined (see the help page).
  2. ^ a b c "M 79". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 17 November 2006.
  3. ^ Cite error: The named reference AJ112_1487 was invoked but never defined (see the help page).
  4. ^ "Messier 79". SEDS Messier Catalog. Retrieved 30 April 2022.
  5. ^ distance × sin( diameter_angle / 2 ) = 53 ly. radius
  6. ^ a b Cite error: The named reference mnras385_4_1998 was invoked but never defined (see the help page).
  7. ^ López-Corredoira, M.; Momany, Y.; Zaggia, S.; Cabrera-Lavers, A. (2007). "Re-affirming the connection between the Galactic stellar warp and the Canis Major over-density". Astronomy & Astrophysics. 472 (3): L47–L50. arXiv:0707.4440. Bibcode:2007A&A...472L..47L. doi:10.1051/0004-6361:20077813. S2CID 17662347.
  8. ^ Myeong, G.C.; Evans, N.W.; Belokurov, V.; Sanders, J.L.; Koposov, S. (2018). "The Sausage globular clusters". The Astrophysical Journal. 863 (2): L28. arXiv:1805.00453. Bibcode:2018ApJ...863L..28M. doi:10.3847/2041-8213/aad7f7. S2CID 67791285.
  9. ^ Carballo-Bello, Julio A.; Martínez-Delgado, David; Navarrete, Camila; Catelan, Márcio; Muñoz, Ricardo R.; Antoja, Teresa; Sollima, Antonio (2017), "Tails and streams around the Galactic globular clusters NGC 1851, NGC 1904, NGC 2298 and NGC 2808", Monthly Notices of the Royal Astronomical Society, 474: 683–695, arXiv:1710.08927, doi:10.1093/mnras/stx2767