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THE ASTRONOMER Electronic Circular No 1181      1997 Apr 05 12.00UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.DEMON.CO.UK             GMH at AST.STAR.RL.AC.UK
WORLD WIDE WEB                    http://www.demon.co.uk/astronomer
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SUPERNOVA 1997bm IN IC 705
     J. Mueller reports her discovery of a supernova (mag about 18)
on an IV N plate taken on Mar. 18 by K. M. Rykoski and J. D.
Mendenhall with the 1.2-m Oschin Schmidt Telescope in the course of
the second Palomar Sky Survey.  SN 1997bm is located 8" east and
13".4 north of the center of IC 705 (R.A. = 11h32m.9, Decl. =
+50o14', equinox 2000.0).  A spectrogram obtained by W. Sargent and
A. Baker on Mar. 30 at the 5-m Hale telescope (+ double
spectrograph) indicates this to be a probable type-I supernova.
IAUC 6609 (extract)

SUPERNOVA 1997bn IN UGC 4329
     Qiyuan Qiao, Weidong Li, Yulei Qiu, Yi Zhang, and Jingyao Hu,
Beijing Astronomical Observatory (BAO), on behalf of the BAO
Supernova Survey, report their discovery of a supernova in UGC 4329,
found on unfiltered CCD images taken on Apr. 3.6 and 4.5 UT with
the BAO 0.6-m reflector.  The supernova brightened from mag 16.4 to
16.2 between the two dates.  SN 1997bn is located at R.A. =
8h19m02s.3, Decl. = +21o11'01" (equinox 2000.0), which is 6".0 east
and 8".2 south of the galaxy's nucleus.  Unfiltered CCD images of
the same field taken on Mar. 27.6 (limiting mag about 18.0) show no
star at the position of the supernova.  A low-resolution spectrum
taken by Y.-q. Qu, Chinese University of Science and Technology;
and J.-y. Wei, D.-w. Xu, and W.-d. Li, BAO, on Apr. 4.7 with the
BAO 2.16-m telescope of Xinglong station shows this to be a type-II
supernova prior to optical maximum.  Weak yet conspicuous hydrogen
Balmer lines are seen superimposed on a very blue continuum.  The
He I 587.6-nm line is also present.  The expansion velocity derived
from the P-Cyg profile of H-alpha is about 16 000 km/s.  The
recession velocity of the host galaxy is about 6300 km/s, as
derived from the narrow H-alpha emission line.
IAUC 6612 (extract)

SUPERNOVA 1997bo IN ANONYMOUS GALAXY
     The BAO Supernova Survey also reports their discovery of
another supernova (mag about 16.1) on unfiltered CCD images taken
on Apr. 3.6 and 4.6 UT with the BAO 0.6-m reflector.  SN 1997bo is
located at R.A. = 12h19m52s.6, Decl. = +7 43'50" (equinox 2000.0).
Prediscovery images yield the following magnitudes:  Mar. 15, 15.9;
27, 16.1.  No star was visible on an image taken on 1991 Jan. 27.
The supernova is several times brighter than the host galaxy.  A
nearby star (R about 15.4) has position end figures 53s.01, 48".3.
A low-resolution spectrum, taken on Apr. 4.8 by J.-y. Wei, D.-w.
Xu, and W.-d. Li, and Y.-q. Qu, shows this to be a type-II
supernova, possibly at plateau phase.  There are very strong
hydrogen Balmer lines, and the Ca II infrared triplet is also
present.  There are some Fe lines at the blue end of the spectrum,
though it is difficult to discern them because of the medium
signal-to-noise ratio.  The expansion velocity of the supernova
envelope is about 7000 km/s, as derived from the absorption minimum
of H-alpha.  There is strong, narrow H-alpha and O I 557.7-nm
emission of the host galaxy on the spectrum, with the recession
velocity measured as about 3690 km/s.
IAUC 6612 (extract)

Martin Mobberley