[vsnet-alert 3835] SN 1999gn in NGC 4303 = Messier 61

[Hitoshi YAMAOKA <yamaoka@rc.kyushu-u.ac.jp>]

Dear SN watchers,

  An Italian amateur A. Dimai has discovered an apparent supernova in
a famous galaxy Messier 61. Congratulations!

  According to IAUC 7335, the discovery was made on the image taken at
Dec. 17.22, when the new object was mag 16.0.  On the next day, it was
confirmed by the KAIT image at mag about 15.5.  It is probably in the
rising phase.  The posision of SN is:  R.A. = 12h21m57s.02, Decl. =
+4o27'45".6 (2000.0), which is about 32" east and 40" south of the
nucleus of the face-on spiral galaxy M61. SN is superimposed on the
bright arm, and on the location there is somewhat dim condensation on
DSS image.  There are a lot of condensations in the arms.

  M61 has produced at least 3 supernovae in this century: SNe 1926A,
1961I, and 1964F.  According to NED, their types and maxima are: SN
1926A, type IIL, 14pv; SN 1961I, type II, 13.0; SN 1964F, type I,
14.0.  M61 is probably a member of the Virgo cluster, and even if not,
it is not twice far beyond the Virgo.  It can be rise to 12 mag order.
The type of SN has not specified.  The followup observations are
strongly needed and urged.

Sincerely Yours,
Hitoshi YAMAOKA, Kyushu Univ., Japan
yamaoka@rc.kyushu-u.ac.jp

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