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IAUC 7820: 2002ap

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                                                  Circular No. 7820
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://cfa-www.harvard.edu/iau/cbat.html  ISSN 0081-0304
Phone 617-495-7440/7244/7444 (for emergency use only)

     S. Mattila and P. Meikle, Imperial College, London, report
that SN 2002ap continues to brighten in the infrared, as indicated
by the following magnitudes from observations obtained by K.
Chambers (Institute for Astronomy, University of Hawaii) at the
U.K. Infrared Telescope (+ infrared imager UFTI):  Feb. 3.2 UT, I =
12.62, Z = 12.44, J = 12.39, H = 12.23, K = 12.20; 4.2, 12.51,
12.30, 12.27, 12.08, 11.94.
     L. Wang, Lawrence Berkeley National Laboratory; D. Baade,
European Southern Observatory (ESO); C. Fransson, Stockholm
Observatory; P. Hoeflich, University of Texas; P. Lundqvist,
Stockholm Observatory; and J. C. Wheeler, University of Texas,
report that high-quality spectropolarimetry (range 350-860 nm;
spectral resolution 1.27 nm and 0.265 nm/pixel) of SN 2002ap was
obtained with the ESO Very Large Telescope UT3 (+ FORS1) on Feb. 3
UT.  A broad spectral absorption feature at 650-800 nm (which, if
due to the Ca II infrared triplet, implies an expansion velocity of
order 45 000 km/s) shows a degree of polarization distinctively
different from other parts of the observed spectrum.  The degree of
polarization of this feature peaks at 735.1 nm (with FWHM = 64.3
nm) and differs by > 1.1 percent when compared to neighboring
wavelength regions.  As the contribution from interstellar dust is
uncertain, the observed 1.1-percent difference should be regarded
as a lower limit to the polarization intrinsic to the supernova and
implies the presence of significantly asymmetric ejecta.  Further
spectropolarimetric observations are encouraged.
     P. Vreeswijk, University of Amsterdam; and S. Smartt,
Institute of Astronomy, Cambridge, report that images taken by G.
Gilmore and R. Wyse on the Isaac Newton Telescope at La Palma on
Feb. 2.9 UT have allowed an accurate projection of the position of
SN 2002ap onto the prediscovery images reported on IAUC 7816:
"Within the new errors, the supernova is not coincident with the V
= 21.2 object reported as a possible progenitor.  The difference in
position between SN 2002ap and this object is 1".7 +/- 0".3, where
the error is dominated by the error in the position of the faint
object, indicating that this was a chance alignment.  There is no
object in the prediscovery images at the supernova position, to
limiting (5-sigma, 2" aperture radius) magnitudes of U = 20.8, B =
22.1, V = 22.0, I = 20.8."
     W. Hasubick, Buchloe, Germany, reports that CCD frames taken
on Jan. 4.795 UT show nothing at the position of SN 2002ap
(limiting red mag 18.5).  CCD R magnitudes by K. Hornoch,
Lelekovice, Czech Republic:  Jan. 31.808 UT, 13.04; Feb. 2.764,
12.66; 3.749, 12.53.

                      (C) Copyright 2002 CBAT
2002 February 5                (7820)            Daniel W. E. Green

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