Circular No. 6788
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
URL http://cfa-www.harvard.edu/iau/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)


GRB 971214
     N. Itoh, Y. Nakada, and T. Soyano, Kiso Observatory,
University of Tokyo, report:  "The GRB error circle was surveyed
done to I = 20 and R = 21 with the Kiso 1.05-m Schmidt telescope on
Dec. 15.8 UT.  The R-band image shows no new objects brighter than
the limiting magnitude of the second Palomar Sky Survey.  The I-
band image from three 10-min exposures revealed one faint object
54" northeast of the BeppoSAX position, at R.A. = 11h56m25s.2,
Decl. = +65o11'57".9 (equinox 2000.0; +/- 6"), I = 19.7 +/- 0.5."
     J. Halpern, J. Thorstensen, D. Helfand, E. Costa, and the
BeppoSAX team have detected a fading optical transient within the
error circle of GRB 971214 (IAUC 6787) in a series of I-band images
taken on the MDM Observatory 2.4-m telescope on Kitt Peak.  The
position is R.A. = 11h56m26s.40, Decl. = +65o12'00".5 (equinox
2000.0).  The I magnitude was 21.2 +/- 0.3 on Dec. 15.47 UT, and
near the detection limit of 22.6 on Dec. 16.47.  Images will be
made available at http://www.astro.columbia.edu/~cba/mdm/.


XTE J0053-724
     R. Corbet, Goddard Space Flight Center (GSFC) and Universities
Space Research Association (USRA); F. E. Marshall, GSFC; J. C.
Lochner, GSFC and USRA; and M. Ozaki and Y. Ueda, Institute of
Space and Astronautical Science, report:  "After the apparent
detection of SMC X-3 with RXTE (IAUC 6777), we performed ASCA
observations on Dec. 12.  While no source was found at the location
of SMC X-3 itself, a source was detected about 8' away, at R.A. =
0h53m53s, Decl. = -72o26'42" (equinox 2000.0; +/- 1'.2, 90-percent
confidence) that exhibited modulation at the 92-s period seen with
RXTE, confirming that this is the same source.  The mean countrate
(per GIS detector) of 0.08 counts/s corresponds to a 2-10-keV flux
of 1.45 x 10E-11 erg sE-1 cmE-2.  A search of archival ROSAT images
reveals a variable source in this error box located at position end
figures 55s, 48" (+/- 5")."
     Lochner and L. A. Whitlock, GSFC and USRA; and N. Brandt,
Pennsylvania State Universtity, report:  "In a preliminary analysis
of the RXTE PCA observations of XTE J0053-724 from Nov. 25-Dec. 11,
the spectra have been fit with a cutoff power law (with photon
indices typically 0.5-0.7 and energy cutoffs in the range 11-15
kev) show no evidence for intrinsic x-ray absorption.  Flux
measurements in the range 2-10 keV are as follows (units of 10E-11
erg sE-1 cmE-2):  Nov. 25.46 UT, 6.72; 27.45, 6.74; 29.25, 6.51;
Dec. 2.18, 6.06; 2.35, 5.97; 5.18, 5.30; 8.06, 4.82; 11.85, 4.12.
The average pulsation period measured from these observations is
91.13 s."

                      (C) Copyright 1997 CBAT
1997 December 16               (6788)            Daniel W. E. Green