[vsnet-alert 2977] SN 1999cd in NGC 3646

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

Dear SN watchers,

  IAUC 7169 announced that the LOSS KAIT team has discovered a new
supernova in nearby galaxy shortly after 1999bz.  This new supernova,
1999cd, is located at R.A. = 11h21m42s.89, Decl. = +20o09'24".1
(2000.0), which is about 4" west and 46" south of the core of the host
Sc galaxy NGC 3646.  The apperance of the host is somewhat peculiar;
its disk seems to be very bright ring surrounding the core, like the
famous Cartwheel interacting galaxy.  The location of the SN is
somewhat outside of the ring, and roughly on the H II region of the
host.  The present magnitude of this object is reported as about 17.5,
and rising now. 

  There are a few confusing (probably) foreground stars:
    R.A.   (2000.0) Decl.       offset     mag about
1. 11h21m44s.87  +20o09'07".6  25"E,62"S   16        U1050_06584526
2. 11h21m41s.41  +20o10'37".9  29"W,25"N   15
3. 11h21m39s.27  +20o09'39".3  55"W,40"S   16        U1050_06584142

Star 2 and 3 locates on the ring, so they can be bright H II regions.

  The recession velocity of the host is about 4200 km/s, which inplies
that the expected SNeIa maximum is around 15 mag.  However, the past
supernova in the same galaxy, 1989N, had the maximum about 14 mag
although it is of type II.  It is likely that this galaxy would be
nearer than estimated from recession velocity.  Followup observation
is encouraged.

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

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