Astronomy:SN 1998aq

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SN 1998aq
Event typeSupernova
Spectral classType Ia[1]
DateApril 13, 1998[2]
ConstellationUrsa Major
Right ascension 11h 56m 25.87s[1]
Declination+55° 07′ 43.2″[1]
Distance70.38 ± 0.23 Mly (21.58 ± 0.07 Mpc)[3]
HostNGC 3982[1]
Colour (B-V)−0.18[4] (peak)
Peak apparent magnitude12.36[1]

SN 1998aq is a nearby supernova located in the intermediate spiral galaxy NGC 3982, offset 18 west and 7″ of the galactic nucleus. It was discovered April 13, 1998 by amateur astronomer Mark Armstrong[2] and was confirmed by fellow British amateur Ron Arbour; both members of the U.K. Supernova/Nova Patrol.[4] The event was not visible on a prior check by Armstrong made April 7.[5] It reached peak brightness on April 27, and 15 days later had declined by 1.14 magnitudes in the B (blue) band.[4]

Spectrum of SN1998aq, a Type Ia supernova, one day after maximum light in the B band[6]

Spectroscopic observations determined this was a Type Ia supernova event, and it became one of the best-studied supernova of its type, at least in the visual band.[4] An absorption feature of singly-ionized carbon was (probably) detected nine days before maximum, an indication of unburned ash left over from the original carbon-oxygen core of the progenitor white dwarf.[7] Brightness calibration using Cepheid variables in NGC 3982 gives a peak absolute magnitude estimate of at least −19.47±0.15 (assuming no extinction in the host galaxy).[8]

References

  1. 1.0 1.1 1.2 1.3 1.4 Barbon, R. et al. (2008). Asiago Supernova Catalogue. Bibcode2008yCat....1.2024B. 
  2. 2.0 2.1 Hurst, G. M. et al. (April 1998). Green, D. W. E.. ed. "Supernova 1998aq in NGC 3982". IAU Circular 6875: 1. Bibcode1998IAUC.6875....1H. 
  3. Tully, R. Brent et al. (October 2013). "Cosmicflows-2: The Data". The Astronomical Journal 146 (4): 25. doi:10.1088/0004-6256/146/4/86. 86. Bibcode2013AJ....146...86T. 
  4. 4.0 4.1 4.2 4.3 Branch, David et al. (September 2003). "Optical Spectra of the Type Ia Supernova 1998aq". The Astronomical Journal 126 (3): 1489–1498. doi:10.1086/377016. Bibcode2003AJ....126.1489B. 
  5. Hewitt, N. (April 2000). "The first seven UK supernova discoveries". Journal of the British Astronomical Association 110 (2): 65–79. Bibcode2000JBAA..110...65H. 
  6. Matheson, T. et al. (2008). "Optical Spectroscopy of Type Ia Supernovae". Astronomical Journal 135 (4): 1598–1615. doi:10.1088/0004-6256/135/4/1598. Bibcode2008AJ....135.1598M. 
  7. Parrent, Jerod T. et al. (May 2011). "A Study of Carbon Features in Type Ia Supernova Spectra". The Astrophysical Journal 732 (1): 15. doi:10.1088/0004-637X/732/1/30. 30. Bibcode2011ApJ...732...30P. 
  8. Saha, A. et al. (November 2001). "Cepheid Calibration of the Peak Brightness of Type Ia Supernovae. XI. SN 1998aq in NGC 3982". The Astrophysical Journal 562 (1): 314–336. doi:10.1086/323529. Bibcode2001ApJ...562..314S. 

External links