Event type Supernova Right ascension 11 46 06.25 Constellation Ursa Major | Spectral class IIn Declination +47° 28' 55.5 | |
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Other designations SN 1998S, 2MASS J11460613+4728553, AAVSO 1140+48 Date March 2, 1998 by Z. Wan. Similar NGC 3877, SN 2006jc, SN 1993J, SN 1979C, SN 2006gy | ||
SN 1998S was a type IIn supernova that was observed in NGC 3877 in March 1998. SN 1998S was the brightest type IIn event observed .
It was discovered on 1998 March 2.68 UT in NGC 3877 by Z. Wan at a broadband (unfiltered) optical magnitude of +15.2.
Its spectrum showed prominent H and He emission lines with narrow peaks and broad wings, superimposed on a blue continuum. These narrow lines indicate the presence of a dense circumstellar medium (CSM) in the vicinity of the supernova. The high luminosity of SN1998S is due to the interaction of fast material (ejecta) with previously-expelled slowly-expanding material (CSM), which can more effectively convert kinetic energy of ejecta into radiation energy.
References
SN 1998S Wikipedia(Text) CC BY-SA