NGC 7331

Coordinates: Sky map 22h 37m 04.1s, +34° 24′ 56″
Source: Wikipedia, the free encyclopedia.
J2000 epoch)
ConstellationPegasus
Right ascension22h 37m 04.1s[1]
Declination+34° 24′ 56″[1]
Redshift816 ± 1 km/s[1]
Distance39.8 ± 3.3 Mly (12.2 ± 1.0 Mpc) [2]
Apparent magnitude (V)10.4[1]
Characteristics
TypeSA(s)b[1]
Size120,000 ly (diameter)
Apparent size (V)10.5′ × 3.7′[1]
Other designations
UGC 12113, PGC 69327,[1] Caldwell 30
Image of a supernova that appeared in the galaxy in 2014 (called 2014C). The inset images are from NASA's Chandra X-ray Observatory, showing a small region of the galaxy before the supernova explosion (left) and after it (right). Red, green and blue colors are used for low, medium and high-energy X-rays, respectively.

NGC 7331, also known as Caldwell 30, is an unbarred spiral galaxy about 40 million light-years (12 Mpc) away in the constellation Pegasus. It was discovered by William Herschel in 1784.[3] NGC 7331 is the brightest galaxy in the field of a visual grouping known as the NGC 7331 Group of galaxies. In fact, the other members of the group, NGC 7335, 7336, 7337 and 7340, lie far in the background at distances of approximately 300–350 million light years.[4]

The galaxy appears similar in size and structure to the

opposite direction to the rest of the disk.[7]
In both visible light and infrared photos of the NGC 7331, the core of the galaxy appears to be slightly off-center, with one side of the disk appearing to extend further away from the core than the opposite side.

Multiple

Milton Humason and H. S. Gates in a survey at Palomar Observatory.[9] More recent supernovae are SN 2013bu (type II, mag. 16.6)[10] and SN 2014C, the latter of which underwent an unusual "metamorphosis" from a hydrogen-poor Type Ib to a hydrogen-rich Type IIn
over the course of a year . [11] A 1903 photographic plate from Yerkes Observatory shows a magnitude 16.6 candidate transient that may have also been a supernova.[12]


See also

References

  1. ^ a b c d e f g h "NASA/IPAC Extragalactic Database". Results for NGC 7331. Retrieved 2006-11-10.
  2. S2CID 551714
    .
  3. ^ The NGC/IC Project Archived 2011-02-28 at the Wayback Machine : NGC Discoverers List by Bob Erdmann.
  4. ^ "Spiral Galaxy NGC 7331, Galaxy Group (NGC 7335, 7336, 7337)".
  5. Spitzer Science Center. 2004-06-28. Archived from the original
    on May 17, 2007. Retrieved 2008-04-24.
  6. ^ "The Milky Way Has Only Two Spiral Arms". 2008-06-03. Retrieved 2008-06-04.
  7. ^ A Counter-rotating Bulge in the Sb Galaxy NGC 7331 , F. Prada, C. Gutierrez, R.F. Peletier, C.D. McKeith, the Astrophysical Journal, 463 :L9–L12, 20/5/1996
  8. ^ "NASA/IPAC Extragalactic Database". Results for SN 1959D. Retrieved 2006-11-10.
  9. doi:10.1086/127513
    .
  10. ^ Transient Name Server entry for SN 2013bu. Retrieved 6 May 2024.
  11. S2CID 31773513
    .
  12. S2CID 231573185
    .

External links


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