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IAUC 5780: 1993L; 1993J

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                                                  Circular No. 5780
Central Bureau for Astronomical Telegrams
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505

     Robert Evans, Hazelbrook, New South Wales, Australia, reports
his visual discovery of an apparent supernova located about 40"
west and 15" north of the center of IC 5270 (R.A. = 22h55m.2, Decl.
= -36 07', equinox 1950.0).  Upon first detection at Apr. 30.8 UT,
he estimated mv about 14.  R. H. McNaught, Anglo-Australian
Observatory, reports the following precise position from a short
exposure taken in twilight on Apr. 30.83 with the Uppsala Southern
Schmidt telescope:  R.A. = 22h55m05s.81, Decl. = -36 07'31".0
(equinox 1950.0, uncertainty 0".4 in each coordinate); the galaxy
was only weakly recorded, but the supernova appears due west.

     S. R. Trammell, D. C. Hines, and J. C. Wheeler, University of
Texas, report:  "Optical spectropolarimetry (range 420-690 nm;
dispersion 0.269 nm/pixel) was obtained with the 2.7-m telescope (+
Large Cassegrain Spectrograph) at McDonald Observatory on Apr.
20.11 UT.  We detect a relatively high polarization of 0.9 +/- 0.1
at angle 33 +/- 3 deg, and there is a 0.5-percent drop in polarization
across H-alpha accompanied by a 10-deg position-angle rotation.
These findings are consistent with those reported by B.
Jannuzzi et al. (IAUC 5776) for data taken after ours on Apr.
26.12.  We measure the polarization of the H-alpha emission alone
to be 1.1 +/- 0.1 at a position angle of 150 +/- 4 deg.  From these
data, we infer the presence of two distinct polarization components
and conclude that at least part of the polarization is intrinsic to
the supernova.  This suggests an asymmetric geometry (see also IAUC
     J. A. Smith, Florida Institute of Technology, reports the
following infrared magnitudes (+/- 0.02 mag unless otherwise noted)
for SN 1993J, obtained using the Kitt Peak 1.3-m telescope (+
SQIID):  Apr. 20.212 UT, J = 10.02, H = 10.02, K = 9.84 +/- 0.03;
21.265, 10.05, 10.02, 9.85 +/- 0.03; 22.165, 10.06, 10.02, 9.87 +/-
0.03; 24.145, 10.14, 10.04, 9.89 +/- 0.03; 25.246, 10.16 +/- 0.01,
10.09, 9.89 +/- 0.03.  Checks were made against the two primary GSC
references reported by Odewahn et al. on IAUC 5760.
     Further photoelectric V photometry (cf. IAUC 5750, 5755) by M.
Okyudo and T. Ishida, Nishi-Harima Astronomical Observatory,
communicated by T. Kato, Kyoto University:  Apr. 23.510 UT, 11.27 (bad
conditions); 25.719, 11.40; 26.583, 11.55; 26.740, 11.46; 27.609,

1993 May 1                     (5780)            Daniel W. E. Green

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