Electronic Telegram No. 495
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html


SUPERNOVA 2006bp IN NGC 3953
     M. T. Kelley and C. J. Stockdale, Marquette University; R. A. Sramek,
National Radio Astronomy Observatory; K. W. Weiler, Naval Research
Laboratory; S. Immler, Goddard Space Flight Center and Universities Space
Research Association; N. Panagia, Space Telescope Science Institute; and
S. D. Van Dyk, Spitzer Science Center, California Institute of Technology,
report the lack of detection of radio emission near the position of the
type-II supernova 2006bp (IAUC 8700; CBET 471) with the Very Large Array:
"Upper limits (3 sigma) to any radio flux density were established on
Apr. 11.97 UT of < 0.414 mJy (spectral luminosity <1.3 x 10^26 erg/s/Hz
for an assumed distance of 16 Mpc) at 22.46 GHz (wavelength 1.3 cm) and <
0.281 mJy at 8.460 GHz (wavelength 3.5 cm), on Apr. 18.27 of < 0.498 mJy
at 14.94 GHz (wavelength 2.0 cm), and on Apr. 20.16 of < 0.276 mJy at
22.46 GHz and < 0.143 mJy at 8.460 GHz.  The search for radio emission
was conducted within about 10" of the published optical position of SN
2006bp (IAUC 8700).  Although only uncertain mass-loss-rate estimates can
be obtained from radio non-detections, under standard assumptions an
upper limit to the radio-determined presupernova mass-loss rate of about
10^-5 to 10^-6 solar masses per year is not inconsistent with the weak
x-ray detection reported by Immler and Brown (CBET 476)."


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2006 CBAT
2006 May 1                       (CBET 495)               Daniel W. E. Green