Triangulum Galaxy

Triangulum Galaxy
Galaxy Messier 33 in Triangulum (the Triangulum Galaxy)
Observation data (J2000 epoch)
Pronunciation/traɪˈæŋɡjʊləm/
ConstellationTriangulum
Right ascension01h 33m 50.02s[1]
Declination+30° 39′ 36.7″[1]
Redshift-0.000607 ± 0.000010[1]
Heliocentric radial velocity-179 ± 3 km/s[2]
Galactocentric velocity-44 ± 6 km/s[2]
Distance970 kpc (3.2 Mly)[3]
Apparent magnitude (V)5.72[1]
Characteristics
TypeSA(s)cd[2]
Mass5×1010[4] M☉
Number of stars40 billion (4×1010)[6]
Size18.74 kpc (61,120 ly)
(diameter; 25.0 mag/arcsec2 B-band isophote)[5][6]
Apparent size (V)70.8 × 41.7 arcminutes[1]
Other designations
IRAS 01310+3024, NGC 598, UGC 1117, MCG +05-04-069, PGC 5818, CGCG 502-110[2]

The Triangulum Galaxy is a spiral galaxy 2.73 million light-years (ly) from Earth in the constellation Triangulum. It is catalogued as Messier 33 or NGC (New General Catalogue) 598. With the D25 isophotal diameter of 18.74 kiloparsecs (61,100 light-years), the Triangulum Galaxy is the third-largest member of the Local Group of galaxies, behind the Andromeda Galaxy and the Milky Way.

The galaxy is the second-smallest spiral galaxy in the Local Group after the Large Magellanic Cloud, which is a Magellanic-type spiral galaxy.[7] It is believed to be a satellite of the Andromeda Galaxy or on its rebound into the latter due to their interactions, velocities,[8] and proximity to one another in the night sky. It also has an H II nucleus.[9]

  1. ^ a b c d e Cite error: The named reference SIMBAD-M33 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference ned was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference vivian was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference mnras342_1 was invoked but never defined (see the help page).
  5. ^ De Vaucouleurs, Gerard; De Vaucouleurs, Antoinette; Corwin, Herold G.; Buta, Ronald J.; Paturel, Georges; Fouque, Pascal (1991). Third Reference Catalogue of Bright Galaxies. Bibcode:1991rc3..book.....D.
  6. ^ a b Cite error: The named reference michon was invoked but never defined (see the help page).
  7. ^ Ryden, Barbara; Peterson, Bradley M. (2009). Foundations of Astrophysics. New York: Pearson Addison-Wesley. p. 471. ISBN 9780321595584.
  8. ^ Cite error: The named reference science307_5714 was invoked but never defined (see the help page).
  9. ^ Ho, Luis C.; Filippenko, Alexei V.; Sargent, Wallace L. W. (October 1997). "A Search for "Dwarf" Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies". Astrophysical Journal Supplement. 112 (2): 315–390. arXiv:astro-ph/9704107. Bibcode:1997ApJS..112..315H. doi:10.1086/313041. S2CID 17086638.