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Date: Thu, 13 May 93 01:23:26 +0900
From: nomoto@apsun1.astron.s.u-tokyo.ac.jp
Subject: abstract of the paper
Kato san,
Following is the Abstract of our recent paper entitled "Type IIb
supernova model for SN 1993J in M81" which was already received by
NATURE on May 11 (Japan time) before IAUC 5787 was distributed. A Tex
file for the text and post script files for figures (or fax if you let
me know the fax number) can be sent upon request. The paper was also
already put up as a post-dead-line poster at Tenmon Gakkai.
Best wishes, K. Nomoto 12 May 93
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Type IIb supernova model for SN 1993J in M81
K. Nomoto$^*$, T. Suzuki$^*$, T. Shigeyama$^*$, S. Kumagai$^*$,
H. Yamaoka$^{\dag}$, H. Saio$^{\ddag}$
$^*$ Department of Astronomy, School of Science,
University of Tokyo, Tokyo 113, Japan
$^{\dag}$ Department of Physics, College of General Education,
Kyushu University, Fukuoka 810, Japan
$^{\ddag}$ Department of Astronomy, Faculty of Science,
Tohoku University, Sendai 980, Japan}
Received by NATURE, 11 May 1993
SN 1993J in M81 is providing us with a wealth of new and unique
information on the stellar evolution and explosion as has been made by
SN 1987A. SN 1993J was identified as a type II supernova (SN II) from
the hydrogen feature. However, its optical light curve is quite
unusual, showing two maxima and currently gradually decreasing. Such
a strange optical appearance has made it difficult to identify the
nature of SN 1993J. Here we show that the bolometric light curve of
SN 1993J around the second maximum is in striking agreement with that
of type Ib supernova 1983N as well as its helium star models. This
implies that SN 1993J produced $\sim$ 0.07 $M_\odot$ $^{56}$Co whose
decay is currently powering the light curve. This also suggests that
SN 1993J has a very thin hydrogen-rich envelope and its spectral
features will change from SN II to SN Ib, thereby be classified as a
type IIb supernova. We suggest that the progenitor lost most of its
envelope by a binary interaction; this binary model can account for
the reported asymmetry of SN 1993J.
Return to the Powerful Daisaku Nogami
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