SN 1993J
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "SN_1993J".

A GALEX image of Messier 81 in ultraviolet light. Credit:GALEX/NASA/JPL-Caltech.
A GALEX image of Messier 81 in ultraviolet light. Credit:GALEX/NASA/JPL-Caltech.

SN 1993J is a supernova observed in the galaxy M81. It was discovered on 28 March 1993 by F. Garcia in Spain[1]. At the time, it was the second brightest supernova observed in the twentieth century[2].

The spectral characteristics of the supernova changed over time. Initially, it looked more like a type II supernova (a supernova formed by the explosion of a giant star) with strong hydrogen spectral line emission, but later the hydrogen lines faded and strong helium spectral lines appeared, making the supernova look more like a type Ib[2][3]. Moreover, the variations in SN 1993J's luminosity over time were not like the variations observed in other type II supernovae[4][5] but did resemble the variations observed in type Ib supernovae[6]. Hence, the supernova has been classified as a "type IIb", a transitory class between type II and type Ib[3]. The scientific results from this supernova suggested that type Ib and Ic supernovae were actually formed through the explosions of giant stars through processes similar to what takes place in type II supernovae[3][7]. The supernova was also used to estimate a distance of 8.5 ± 1.3 Mly (2.6 ± 0.4 Mpc) to Messier 81[2].

Light echos from the explosion have subsequently been detected. [8]

References

  1. ^ J. Ripero, F. Garcia, D. Rodriguez, P. Pujol, A. V. Filippenko, R. R. Treffers, Y. Paik, M. Davis, D. Schlegel, F. D. A. Hartwick, D. D. Balam, D. Zurek, R. M. Robb, P. Garnavich, B. A. Hong (1993). "Supernova 1993J in NGC 3031". IAU Circular 5731. 
  2. ^ a b c B. P. Schmidt, R. P. Kirshner, R. G. Eastman, R. Grashuis, I. dell'Antonio, N. Caldwell, C. Foltz, J. P. Huchra, A. A. E. Milone (1993). "The unusual supernova SN1993J in the galaxy M81". Nature 364: 600–602. doi:10.1038/364600a0. 
  3. ^ a b c A. V. Filippenko, T. Matheson, L. C. Ho (1993). "The "Type IIb" Supernova 1993J in M81: A Close Relative of Type Ib Supernovae". Astrophysical Journal Letters 415: L103–L106. doi:10.1086/187043. 
  4. ^ P. J. Benson, W. Herbst, J. J> Salzer, G. Vinton, G. J. Hanson, S. J. Ratcliff, P. F. Winkler, D. M. Elmegreen, F. Chromey, C. Strom, T. J. Balonek, B. G. Elmegreen (1994). "Light curves of SN 1993J from the Keck Northeast Astronomy Consortium". Astronomical Journal 107: 1453–1460. doi:10.1086/116958. 
  5. ^ J. C. Wheeler, E. Barker, R. Benjamin, J. Boisseau, A. Clocchiatti, G. de Vaucouleurs, N. Gaffney, R. P. Harkness, A. M. Khokhlov, D. F. Lester, B. J> Smith, V. V. Smith, J. Tomkin (1993). "Early Observations of SN 1993J in M81 at McDonald Observatory". Astrophysical Journal 417: L71–L74. doi:10.1086/187097. 
  6. ^ M. W. Richmond, R. R. Treffers, A. V. Filippenko, Y. Palik, B. Leibundgut, E. Schulman, C. V. Cox (1994). "UBVRI photometry of SN 1993J in M81: The first 120 days". Astronomical Journal 107: 1022–1040. doi:10.1086/116915. 
  7. ^ A. V. Filippenko, T. Matheson, A. J. Barth (1994). "The peculiar type II supernova 1993J in M81: Transition to the nebular phase". Astronomical Journal 108: 2220–2225. doi:10.1086/117234. 
  8. ^ Sugerman, Ben and Crotts, Arlin (November 8, 2002). "Multiple Light Echoes from Supernova 1993J". Columbia University.


content
Please improve this article  This star-related article is a stub. You can help Wikipedia by expanding it.
© jGames.co.uk 2007 (some content from Wikipedia under GDL ) !-- ValueClick Media 468x60 and 728x90 Banner CODE for jgames.co.uk -->
Your Ad Here