NGC 5474

NGC 5474

Hubble image of NGC 5474.[1]
Observation data (J2000 epoch)
Constellation Ursa Major[2]
Right ascension 14h 05m 01.6s[3]
Declination +53° 39 44[3]
Redshift 273 ± 9 km/s[3]
Distance 21.2 ± 2.2 Mly (6.5 ± 0.7 Mpc)[3]
Type SA(s)cd pec[3]
Apparent dimensions (V) 4.8 × 4.3[3]
Apparent magnitude (V) 11.3[3]
Other designations
UGC 9013,[3] PGC 50216[3]

NGC 5474 is a peculiar dwarf galaxy in the constellation Ursa Major. It is one of several companion galaxies of the Pinwheel Galaxy (M101), a grand-design spiral galaxy.[4][5] Among the Pinwheel Galaxy's companions, this galaxy is the closest to the Pinwheel Galaxy itself.[4] The gravitational interaction between NGC 5474 and the Pinwheel Galaxy have strongly distorted the galaxy. As a result, the disk is offset relative to the nucleus.[4][6] The star formation in this galaxy (as traced by hydrogen spectral line emission) is also offset from the nucleus.[6] NGC 5474 shows some signs of a spiral structure. As a result, this galaxy is often classified as a dwarf spiral galaxy, a relative rare group of dwarf galaxies.

References

  1. "A dwarf galaxy ravaged by grand design". Picture of the Week. ESA/Hubble. Retrieved 17 June 2014.
  2. R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation and Cambridge University Press. ISBN 0-933346-51-4.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 "NASA/IPAC Extragalactic Database". Results for NGC 5474. Retrieved 2006-09-20.
  4. 4.0 4.1 4.2 Drozdovsky, I. O; Karachentsev, I. D (2000). "Photometric distances to six bright resolved galaxies". Astronomy and Astrophysics Supplement 142 (3): 425–432. Bibcode:2000A&AS..142..425D. doi:10.1051/aas:2000155.
  5. A. Sandage; J. Bedke (1994). Carnegie Atlas of Galaxies. Washington, D.C.: Carnegie Institution of Washington. ISBN 0-87279-667-1.
  6. 6.0 6.1 R. M. Gonzalez Delgado; E. Perez; C. Tadhunter; J. M. Vilchez; J. M. Rodriguez-Espinosa (2000). "H II Region Population in a Sample of Nearby Galaxies with Nuclear Activity. I. Data and General Results". Astrophysical Journal Supplement 108 (1): 155. Bibcode:1997ApJS..108..155G. doi:10.1086/312951.