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IAUC 7124: 1999an; 1999ao; N Mus 1998

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                                                  Circular No. 7124
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7244/7440/7444 (for emergency use only)

SUPERNOVA 1999an IN IC 755
     J. Y. Wei, L. Cao, Y. L. Qiu, Q. Y. Qiao, and J. Y. Hu,
Beijing Astronomical Observatory (BAO), report the discovery by the
BAO Supernova Survey of a supernova (unfiltered mag about 15) with
the 0.6-m telescope at Xinglong Station on Mar. 7.83 UT.  SN 1999an
is located at R.A. = 12h01m10s.5, Decl. = +14o06'11" (equinox
2000.0), close to the nucleus of IC 755.  SN 1999an also appears on
images taken on Jan. 22.85, 26.84, Feb. 7.89, and 15.79.  A low-
resolution spectrum (range 400-820 nm), obtained by L. Cao and Q. S.
Gu with the BAO 2.16-m telescope on Mar. 10.8, shows SN 1999an to
be a type-II supernova with obvious P-Cyg Balmer lines.  Strong,
narrow emission lines from H II regions also appear in the spectrum
and show that IC 755 has a redshift of 0.004.  A photospheric
expansion velocity of 5300 km/s was obtained from the H-alpha P-Cyg

     D. Reiss, University of Washington, and the Mt. Stromlo Abell
Cluster Supernova Search Team (cf. IAUC 7106) report the discovery
of a supernova (V about 18.2, R about 18.4) on a CCD image obtained
on Mar. 3 by S. Sabine with the Mt. Stromlo 1.27-m telescope (+
Macho Camera).  SN 1999ao is located near Abell 3392 at R.A. =
6h27m26s.37, Decl. = -35o50'24".2 (equinox 2000.0), which is 2".3
west and 0".9 north of the nucleus of the host galaxy; a nearby
star has position end figures 27s.34, 51'09".3.  SN 1999ao is not
visible on similar frames taken on Jan. 10 (limiting mag 20.5).
CCD UBVRI images obtained at the Cerro Tololo 0.9-m telescope on
Mar. 8 and 9 by L. Germany also show the new star.  A spectrum
(range 320-900 nm) taken by B. Schmidt at the Australian National
University's 2.3-m telescope on Mar. 10.5 UT shows that SN 1999ao
is a type-Ia event, about 8 days before maximum brightness; its
redshift (z = 0.054), obtained from Ca H and K features, is nearly
identical to that of Abell 3392 (z = 0.055).

     A. Retter, Keele University; W. Liller, Vina Del Mar, Chile;
and G. Garradd, Loomberah, N.S.W., write:  "Analysis of CCD
continuous photometry of N Mus 1998 through wide-band filters
during 15 nights in Jan.-Feb. reveals a periodic oscillation.  The
period is either 0.16930 +/- 0.00015 day or its 1-day alias of
0.20380 +/- 0.00025 day.  The semiamplitude of the variation is
about 0.03 mag.  Most of the observations were carried out during
the transition phase of the nova.

                      (C) Copyright 1999 CBAT
1999 March 11                  (7124)            Daniel W. E. Green

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