[vsnet-alert 3830] SNe 1999gk and 1999gl

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

[vsnet-chart 238] Chart of SN1999gk
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chart/msg00238.html
[vsnet-chat 2458] Host galaxy of SN1999gk
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chat/msg02458.html
[vsnet-chat 2459] Photometric sequence for SN1999gk
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chat/msg02459.html
[vsnet-chart 239] Chart of SN1999gl
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chart/msg00239.html
[vsnet-chat 2460] Host galaxy of SN1999gl
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chat/msg02460.html

Dear SN watchers,

  Two considerably bright type-II SNe are discovered.  One of them is
a serendipotous discovery, and the other is quite bright as its
distance.  Each are reported in IAUC 7332 and 7333, respectingly. 

  SN 1999gk was discovered on Dec. 15.53 UT by P. Berlind during the
course of spectroscopic observations with FLWO 1.5-m telescope.  The
position is R.A. = 12h43m51s.91, Decl. = -0o32'55".4 (2000.0), which
is about 46" north and 15" east from the core of the Scd galaxy NGC
4653.  It is superimposed on the outer arm.  At the quite
neighbourhood of the reported SN position,  USNO 0825_07850400 (r =
18.5) is there, which seems to be a condensation in the host galaxy.
The spectrum of this SN shows that it is of type II.  The reporters
noted that the H-alpha profile is quite peculiar --- having two minima
in its absorption, which is possibly due to an asymmetric expansion.
The magnitude of the supernova, from the concurrent image, V = 15.7
and R = 15.8.  The distance of the host galaxy, estimated from its
recession velocity, is about 2.5 times away of Virgo cluster.  Then
the reported magnitude is likely a typical SNeII one.  The photometric
sequence has kindly provided by Dr. Kato on vsnet-chat 2459, largely
based on Landolt's standard HA104.  

  The other one, SN 1999gl, was discovered by an English amateur Tom
Boles on Dec. 14.73.  The reported position is: R.A. = 0h57m40s.07,
Decl. = +43o47'35".6 (2000.0), from which the offset is derived as
about 5".3 north and 5".3 west of the core of the Sb(?) galaxy NGC
317B.  The host galaxy is interacting with S0 galaxy NGC 317A, which
is about 14" north and 31" west of NGC 317B.  SN 1999gl is located 
between these two, and superimposed on the arm of NGC 317B. 

  CfA group has taken a spectrum of this SN, which reveals that it is
also a type-II event.  It also indicate that SN is heavily
extinguished by the interstellar dust in the host galaxy.  The
recession velocities of these pair of galaxies are about 5400 km/s in
RC3, and is coincident with the redshift reported in IAUC.  It
indicates that this SN is somewhat distant --- the maximum of typical
SNeII is 18.0 mag even without extinction.  It is a quite surprise
that SN 1999gl was discovered on 16.2 mag!  SN 1999gl should be very
bright SNII.  Followup observations are surely exciting.

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

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