[vsnet-alert 2540] SNe 1999B and 1999D

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

Dear SN watchers,

There are two newly-discovered supernovae which are quite remarkable.

The first one, SN 1999B, had been discovered by M. Schwartz.  It was
his 9th SNe discovery.  Congratulations, Mike!

Its discovery has been announced on IAUC 7086.  The location is; R.A.
= 12h11m16s.11, Decl. = +74o48'06".9 (2000.0), which is about 2" west
and 20" south of the nucleus of the host galaxy UGC 7189.  The host
has a bright bar-shaped core and dim spiral arms (type SBdm), and the
new star appears to be on the south-west edge of the disk.  There are
confusing three foreground stars (mag 13-14) around UGC 7189, so
please the observer pay attention to identification.  The discovery
image can be seen at:
http://vsnet.ggw.org/asras/snimages/sn1999/sn99b1.html ,
and the chart can be processed from the data:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chart/msg00125.html

SN 1999B was 16.9 mag in the discovery image taken on Jan. 14.29 UT.
The spectrum of SN 1999B has been obtained by CfA group on Jan. 16.5
UT(IAUC 6088), and it has been revealed that this is to be a type-II
SN in somewhat early phase (with blue continuum).  The recession
velocity of UGC 7189 is very small (1683 km s-1; NASA Extragalactic
Database), which indicate that SN 1999B can be glow some brighter
(say, 15 mag or so) at its maximum.  Further magnitude estimates is
urged. 

Another one, SN 1999D, has been discovered by BAO survey on Jan 16.83
UT.  The host NGC 3690 is a colliding pair of galaxies, and has very
disturbed shape. Remarkable to say, it has been produced four
supernovae (including 1999D) and one possible radio supernova in this
decade (!).  The most recent one, 1998T, gave rise to the discussion
about the identification and the naming of the host galaxy (see IAUC
6859 = http://cfa-www.harvard.edu/iauc/06800/06859.html or my message; 
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chat/msg00797.html).

The location of SN 1999D measured by CfA group (IAUC 7089) is R.A. =
11h28m28s.38, Decl. = +58o33'39".0 (2000.0).  This SN appears to be
the most western point source of NGC 3690 complex. 

The spectrum taken by CfA group revealed that SN 1999D is of type-II
in very early phase.  The expected maximum would be some 16 mag or
a little more brighter.  

The discoverer reported that the new star was 15.6 mag on Jan. 16.83
and was 15.3 mag on 17.65 UT.  However, on the first inspection of CfA
image taken on Jan. 18
(http://cfa-www.harvard.edu/cfa/oir/Research/supernova/images/sn99d.gif),
it is about 16.2 mag.  The USNO-A2.0 based chart is available at:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chart/msg00128.html.
Followup photometry is also encouraged.

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

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