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IAUC 7068: CATACLYSMIC Var IN Aur; 1997eg

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                                                 Circular No. 7068
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
Phone 617-495-7244/7440/7444 (for emergency use only)


CATACLYSMIC VARIABLE IN AURIGA
     J. Y. Wei, Y. L. Qiu, Q. Y. Qiao, and J. Y. Hu, Beijing
Astronomical Observatory (BAO), report their discovery in the
course of the BAO supernova survey of an outburst of the
cataclysmic variable noted on IAUC 6758.  The unfiltered CCD
magnitudes of the star were 16.6 on Dec. 9.73, 16.0 on Dec. 12.73,
and 16.6 on Dec. 14.78 UT.  The star was not present on a CCD image
obtained on Dec. 3.


SUPERNOVA 1997eg IN NGC 5012
     C. K. Lacey and K. W. Weiler, Naval Research Laboratory; R. A.
Sramek, National Radio Astronomy Observatory (NRAO); and S. D. Van
Dyk, Infrared Processing and Analysis Center, California Institute
of Technology, report the detection of radio emission from the
type-IIn supernova 1997eg (IAUC 6790, 6794, 6823, 6917) with the
Very Large Array:  "A radio-flux density of 0.52 +/- 0.06 mJy at
8.44 GHz (wavelength 3.6 cm) on May 31 and 0.53 +/- 0.12 mJy at
8.46 GHz on June 9 has been measured at a position of R.A. =
13h11m36s.71, Decl. = +22o55'28".9 (equinox 2000.0; +/- 0".2 in
each coordinate).  This is in close agreement with the reported
optical position (end figures 36s.73, 29".4; IAUC 6790).
Nondetections of < 0.21 mJy (3 sigma) at 8.44 GHz (wavelength 3.6
cm) and < 0.84 mJy (3 sigma) at 14.96 GHz (wavelength 2.0 cm) on
Feb. 10, < 0.17 mJy (3 sigma) at 4.89 GHz (wavelength 6.0 cm) on
Feb. 13, < 0.44 mJy (3 sigma) at 14.96 GHz (wavelength 2.0 cm) on
May 31, and < 0.60 mJy (3 sigma) at 14.96 GHz (wavelength 2.0 cm)
on June 9 have also been obtained.  Filippenko and Barth (IAUC
6794) predict significant radio and x-ray emission from SN 1997eg
based on comparison of its optical spectral characteristics with
the class of luminous radio and x-ray emitting supernovae
resembling SN 1988Z.  If the Filippenko-Barth prediction is
correct, SN 1997eg could reach a maximum 6-cm flux density of > 10
mJy, assuming a distance of 40 Mpc (Ho et al. 1997, Ap.J. Suppl.
12, 315), as late as four years after explosion.  The above
detections in May-June imply that SN 1997eg was significantly more
radio luminous at 8.46 GHz by age about 180 days than the best-fit
model for the radio emission from SN 1988Z would predict.  We
encourage further multi-wavelength observations."

                      (C) Copyright 1998 CBAT
1998 December 17               (7068)            Daniel W. E. Green

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