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IAUC 7122: 1999am; 1999ac; 1999X, 1999aa

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                                                  Circular No. 7122
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)


SUPERNOVA 1999am IN CGCG 60-009
     G. Aldering and P. Nugent, Lawrence Berkeley National
Laboratory, on behalf of the Supernova Cosmology Project (SCP),
report the discovery of a supernova (unfiltered mag about 17.8) on
Feb. 18 UT as part of a joint collaboration between the SCP and E.
Helin, S. Pravdo, D. Rabinowitz, and K. Lawrence (Near-Earth
Asteroid Tracking project, Jet Propulsion Laboratory).  SN 1999am
is located at R.A. = 8h24m10s.88, Decl. = +12o06'58".6 (equinox
2000.0), which is 11" west of the center of CGCG 060-009.  W.
Kunkel (Carnegie Observatories) and M. Phillips (Carnegie
Institution of Washington) report that a spectrum of the new object
taken on Mar. 3 with the 2.54-m reflector at Las Campanas shows it
to be a type-Ia supernova, nearly 3 weeks after maximum light at a
redshift of about 12 000 km/s.


SUPERNOVA 1999ac IN NGC 6063
     M. M. Phillips, Las Campanas Observatory, Carnegie Institution
of Washington, writes:  "A CCD spectrum (range 365-930 nm) obtained
by M. M. Phillips and W. Kunkel, Carnegie Observatories, on Feb. 28
UT with the Las Campanas 2.5-m duPont telescope shows that SN
1999ac is a peculiar, 1991T-like type-Ia event that has been caught
near, or a few days before, maximum.  This classification is
confirmed by A. V. Filippenko, University of California at Berkeley,
who notes that the spectrum is similar, but somewhat latter in
epoch, to the spectrum of SN 1999aa described on IAUC 7108.  Like
SN 1991T, the Fe III lines at 430 and 500 nm in the spectrum of SN
1999ac are observed to be strong and the Si II 635.5-nm absorption
weak; but unlike 1991T, the Ca II H and K aborption in SN 1999ac is
strong and well-developed."
     Unfiltered CCD magnitude estimates:  Feb. 28.111 UT, 15.3 +/-
0.3 (L. Kiss and K. Sarneczky, Szeged, Hungary); Mar. 3.726, 15.7
(S. Yoshida and K. Kadota, Ageo City, Japan).


SUPERNOVAE 1999X AND 1999aa
     Unfiltered CCD estimates by S. Yoshida and K. Kadota, Ageo
City, Japan:  SN 1999X in CGCG 180-22, Feb. 7.641 UT, 16.5; 22.710,
16.8.  SN 1999aa in NGC 2595, Mar. 3.693, 15.8.

                      (C) Copyright 1999 CBAT
1999 March 6                   (7122)            Daniel W. E. Green

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