NGC 2903

NGC 2903
An ultraviolet image of NGC 2903 taken with GALEX.
Observation data (J2000 epoch)
ConstellationLeo
Right ascension09h 32m 10.111s[1]
Declination+21° 30′ 02.99″[1]
Redshift556±1 km/s[2]
Distance30.4 Mly (9.33 Mpc)[3]
Group or clusterVirgo Supercluster[4]
Apparent magnitude (V)9.0[5]
Characteristics
TypeSBbc[6] or SAB(rs)bc[7]
Size100,000 ly (diameter)
Apparent size (V)11.48′ × 5.25′[8]
Other designations
UGC 5079, IRAS 09293+2143,[9] PGC 27077[2]
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NGC 2903 is an isolated barred spiral galaxy in the equatorial constellation of Leo, positioned about 1.5° due south of Lambda Leonis.[10] It was discovered by German-born astronomer William Herschel, who cataloged it on November 16, 1784. He mistook it as a double nebula, as did subsequent observers, and it wasn't until the nineteenth century that the Third Earl of Rosse resolved into a spiral form.[5] J. L. E. Dreyer assigned it the identifiers 2903 and 2905 in his New General Catalogue; NGC 2905 now designates a luminous knot in the northeastern spiral arm.[11]

This field galaxy[12] is located about 30[3] million light-years away from the Milky Way, and is a member of the Virgo Supercluster.[4] The morphological classification of this galaxy is SBbc,[6] indicating a barred spiral (SB) with moderate to tightly-wound spiral arms (bc). De Vaucouleurs and associates assigned it the class SAB(rs)bc, suggesting a weaker bar structure (SAB) with a partial ring (rs). The bar structure appears stronger in the near infrared band. The galaxy as a whole is inclined by an angle of 60° to the line of sight from the Earth.[7]

72% of the stellar mass is located in the outer disk of the galaxy, and 20% is found in the bar. The bulge adds 5% of the stellar mass, and its star population is generally older.[13] However, the central ~650 pc radius volume of the core is a strong starburst region. The star formation rate here is 0.7 M☉ y−1 and it is being fed by gas inflow along the bar. There is no evidence of an active nucleus.[7]

The irregular dwarf galaxy KKH 51 appears to be a companion, as they have an angular separation of 25′ and nearly the same radial velocity.[14]

  1. ^ a b Cite error: The named reference Skrutskie2006 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference ned was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Tully2016 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference ipac was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference OMeara2007 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Ann2015 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Yukita2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Paturel2003 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Sinnott1997 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Moore2010 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference 1979A&A....74..235M was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Carrillo2020 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Makarova2002 was invoked but never defined (see the help page).