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IAUC 6778: Poss. SN IN UGC 4107; N Sco 1997

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                                                 Circular No. 6778
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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     S. Nakano, Sumoto, Japan, reports the discovery by Yasuo Sano,
Nayoro, Hokkaido, of a possible supernova (R = 16.7) on ten CCD
frames taken around Nov. 25.582 UT with a 0.28-m f/6.3 reflector (+
R filter).  The object is located at R.A. = 7h57m02s.82, Decl. =
+49o33'40".2 (equinox 2000.0), which is about 10" east and 20"
south of the center of UGC 4107.  R. Kushida, Yatsugatake South
Base Observatory, provides the following position end figures
(measured by Y. Kushida) from an unfiltered CCD image that she
obtained on Nov. 26.81 (when the supernova suspect was at mag 16.1)
with a 0.40-m f/5 reflector:  02s.87, 41".3.  There is no star at
this position on the Digital Sky Survey.
     P. Garnavich, S. Jha, R. Kirshner, and P. Challis, Harvard-
Smithsonian Center for Astrophysics, communicate:  "P. Berlind
obtained a spectrogram (range 370-750 nm) of Sano's supernova
candidate in UGC 4107 on Nov. 26.4 UT with the Whipple
Observatory's 1.5-m Tillinghast telescope.  The spectrum is unusual,
showing a continuum with broad (50- to 100-nm) features.  The
continuum peaks near 510 nm and shows local maxima at 440 and 620
nm.  Narrow emission lines from UGC 4107 are also seen and give a
redshift of 3400 km/s.  The spectrum is clearly not that of a
normal star, but from the present evidence, it is not yet possible
to conclude that the object is a supernova.  The spectrum is
available at

     M. Orio and E. Trussoni, Turin Observatory; S. Balman, Middle
Eastern Technical University, Ankara; H. Ogelman and J. Gallagher,
University of Wisconsin; D. de Martino, Naples Observatory; M.
Della Valle, Padua University; C. Gonzalez-Riestra, European Space
Agency; and P. Selvelli, National Research Council of Italy,
Trieste, report:  "N Sco 1997 (cf. IAUC 6678, 6679) was detected
as an x-ray source by the SAX LECS and MECS instruments with
countrates 0.0658 +/- 0.0021 and 0.0190 +/- 0.0007 counts/s,
respectively, on Sept. 23-24 UT in the two instruments.  The
unabsorbed flux from the source is 4.5 x 10E-12 erg cmE-2 sE-1 in
the band 0.1-10 keV, assuming that the emitting material is a
two-component thermal plasma with a column of neutral hydrogen,
N_H, about 2 x 10E21 cmE-2; this assumption is consistent with a
shocked-shell model."

                      (C) Copyright 1997 CBAT
1997 November 26               (6778)            Daniel W. E. Green

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