Circular No. 8696
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVA 2005nc AND GRB 050525A
     M. Della Valle, Istituto Nazionale di Astrofisica (INAF),
Firenze; D. Malesani, International School for Advanced Studies,
Trieste; S. Benetti, INAF, Padova; G. Chincarini, University of
Milano-Bicocca; L. Stella, INAF, Roma; and G. Tagliaferri, INAF,
Brera, on behalf of a larger collaboration (Della Valle et al. 2006,
Ap.J. Let., in press), report the discovery of an apparent
supernova associated with the gamma-ray burst GRB 050525A (Blustin
et al. 2005, Ap.J. 637, 901).  Observations obtained with the
Telescopio Nazionale Galileo and with the Very Large Telescope (VLT)
at the European Southern Observatory show that the early afterglow
light curve is well described by a broken power law with a break
0.3 day after the gamma-ray event.  At about 5 days after the burst,
an apparent flattening is observed starting on May 30 (R magnitudes:
May 30.28 UT, 23.96 +/- 0.15; June 3.28, 24.03 +/- 0.04; 7.24,
24.09 +/- 0.07; 12.30, 24.01 +/- 0.16), followed by a further
dimming (June 30.15, R = 24.59 +/- 0.09; July 6.19, 24.85 +/- 0.08;
Sept. 7.12, 25.04 +/- 0.09; Oct. 1.00, > 25.1).  A measurement of
the position of SN 2005nc from the VLT frames yields R.A. =
18h32m32s.58, Decl. = +26o20'22".6 (equinox 2000.0; uncertainty
0".25); Ryckoff et al. had given position end figures 32s.6, 23".5
(uncertainty about 1"; cf. GCN 3468) for the afterglow.  Inspection
of a 2-hr integrated VLT spectrum (range 500-1000 nm, resolution 2
nm), obtained on 2005 June 28 (36 days after the GRB outburst,
observer frame) confirms the redshift of the parent galaxy reported
by Foley et al. (2005, GCN 3483) to be z = 0.606 and finds
similarities with the early stages of the type-Ic broad-lined
supernova 1998bw (Patat et al. 2001, Ap.J. 555, 900).


COMET P/2006 F1 (KOWALSKI)
     This comet (cf. IAUC 8690) has been found via additional
astrometry, including prediscovery images from Jan. 10, to be of
short period; further astrometry and the following orbital elements
appear on MPEC 2006-F49.

     T = 2008 Feb.  6.3775 TT         Peri. = 184.7393
     e = 0.122551                     Node  = 125.0685  2000.0
     q = 4.134874 AU                  Incl. =  21.1773
       a =  4.712383 AU    n = 0.0963481    P =  10.23 years

                      (C) Copyright 2006 CBAT
2006 March 30                  (8696)            Daniel W. E. Green