Circular No. 6797
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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GRB 971227
     L. Piro and P. Soffitta, Istituto Astrofisica Spaziale, CNR,
Rome; R. C. Butler, Agenzia Spaziale Italiana, Rome; L. A.
Antonelli, F. Fiore, and M. Capalbi, BeppoSAX Science Data Center,
Rome; A. Tesseri and V. Torroni, BeppoSAX Science Operation Center,
Telespazio, Rome; and C. De Libero, BeppoSAX, Operation Control
Center, Telespazio, Rome, report on behalf of the BeppoSAX team: "A
follow-up observation of GRB 971227 was carried out with BeppoSAX
14 hr after the initial burst.  Two previously unknown x-ray
sources were detected within the WFC error circle (IAUC 6796) in
the MECS x-ray telescopes.  1SAX J1257.5+5915 is located at R.A. =
12h57m33s, Decl. = +59o15'27" (equinox 2000.0; error radius about
1'.5, including systematics in the position reconstruction and
statistical errors).  Three radio sources of the NRAO/VLA Sky
Survey catalogue (cf. http://www.cv.nrao.edu/~jcondon/nvss.html)
lie within this error circle; the strongest one has a flux of 20
mJy at 1.4 GHz and is polarized.  The x-ray source does not show
any significant variation during the 20-hr observation.  The
average countrate in the range 1.3-10 keV was 0.0012 +/- 0.0004
counts/s for two MECS units, corresponding to a 2-10-keV flux of 1
x 10E-13 erg cmE-2 sE-1.  The other source, 1SAX J1257.3+5924, was
detected at R.A. = 12h57m15s, Decl. = +59o24'02".  The countrate in
the first 8 hr of the observation was 0.0032 +/- 0.001 counts/s,
which corresponds to a 2-10-keV flux of 3 x 10E-13 erg cmE-2 sE-1.
In the following part of the observation, the source was not
detected, with a 3-sigma upper limit of 0.002 counts/s.  We
conclude that 1SAX J1257.3+5924 is the best candidate for the x-ray
afterglow of GRB 971227."


SUPERNOVA 1997ef IN UGC 4107
     J. Y. Wei, J. Y. Hu, Y. L. Qiu, and Q. Y. Qiao, Beijing
Astronomical Observatory; and J. S. Deng and J. H. You, Shanghai
Jiao Tong University, report the following R magnitudes for SN
1997ef:  Dec. 4.8 UT, 16.4; 11.7, 16.1; 12.7, 16.1; 13.8, 16.2;
16.8, 16.3; 22.8, 16.3; 24.7, 16.2; 26.8, 16.2.


COMET C/1995 O1 (HALE-BOPP)
     Visual m_1 estimates:  Nov. 2.74 UT, 5.9 (T. Karhula,
Yerecoin, W. Australia, naked eye); 18.52, 6.6 (D. Seargent, The
Entrance, N.S.W., 10x50 binoculars); Dec. 4.25, 7.0 (J. de S.
Aguiar, Campinas, Brazil, 11x80 binoculars); 29.53, 7.6 (A.
Pearce, Nedlands, W. Australia, 20x80 binoculars).

                      (C) Copyright 1997 CBAT
1997 December 29               (6797)            Daniel W. E. Green