11 46 06.25
+47° 28' 55.5
| SN 1998S, 2MASS J11460613+4728553, AAVSO 1140+48|
March 2, 1998 by Z. Wan.
NGC 3877, SN 2006jc, SN 1993J, SN 1979C, SN 2006gy
SN 1998S Wikipedia
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.