Central Bureau for Astronomical Telegrams

IAUC 5737: 1993J

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                                                  Circular No. 5737
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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
MARSDEN@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)


SUPERNOVA 1993J IN NGC 3031
     M. Richmond, Princeton University, provides the following J2000.0
position of the supernova, reduced from the Treffers CCD images (IAUC
5731) using the Guide Star Catalogue: R.A. = 9h55m25s.00, Decl. =
+69D01'13".3.  The corresponding end figures for the position by
Hartwick et al. (IAUC 5731) are 25s.00, 13".7.  Richmond gives the
offset from the mag 14 foreground star mentioned on IAUC 5731 (= GSC
4383.0340) as 7".4 east, 24".3 north (7".2 east, 24".3 north at 1950.0).

     W. van Driel, Institute of Astronomy, University of Tokyo, reports:
"On Mar. 25.60 UT an R-band CCD image of M81 was obtained with the
1.05-m Schmidt telescope at the Kiso Observatory by K.-I. Wakamatsu and
myself.  The 5-min exposure was made through a thin cloud layer.  We can
not see the supernova in this image, though we can see the mag 17 star
50" due north of GSC 4383.0340.  On Mar. 31 we took R and V band images
of the supernova for comparison.  The Kiso CCD is 1018 x 1000 pixels of
0".75 square each, giving a field-of-view of about 12'.7 x 12'.5.  We
have performed the bias substraction and flatfielding of the images."

     A. V. Filippenko, University of California at Berkeley, notes:
"The V magnitude and colors (B-V, V-R) of the starlike object reported
on IAUC 5736 at the position of SN 1993J are consistent
with those of an unreddened or slightly reddened K0 Ia supergiant at
the distance of NGC 3031 (distance modulus 27.5 mag).  On page 16 of
the Atlas of Galaxies by Sandage and Bedke (1988) the object is
clearly visible as a stellar or semistellar condensation in the middle
of a spiral arm.  An extended progenitor (red supergiant, rather than
blue supergiant like that of SN 1987A) is consistent with the fact
that SN 1993J is not subluminous in B."

     J. C. Wheeler, University of Texas at Austin, reports: "E. Barker
obtained an essentially featureless spectrum from 300 to 840 nm with
the es2 spectrograph on the 2.1-m telescope at the McDonald Observatory
on Mar. 31.2 UT.  D. Lester, N. Gaffney and B. Smith obtained spectra
with the McDonald Observatory infrared spectrometer on the 2.7-m
telescope, covering the J and K bands at low (R = 100-200) resolution.
These spectra are also basically featureless with no evidence for
Brackett, Paschen or He lines.  Approximate photometry is K = 10.6, J =
10.9 on Mar. 31.2."

     Visual magnitude estimate by M. V. Zanotta and S. Pesci (Milan,
Italy): Mar. 31.84 UT, 10.5.

     Corrigendum.  IAUC 5733: for FWZI about 70 nm read FWZI about
37 nm.


1993 April 1                   (5737)              Brian G. Marsden

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