Circular No. 6657
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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GRB 970508
     A. J. Castro-Tirado and J. Gorosabel, Laboratorio de
Astrofisica Espacial y Fisica Fundamental, Madrid; C. Wolf and R.
Fockenbrock, Max-Planck-Institut fur Astronomie (MPIA), Heidelberg;
E. Martinez-Gonzalez and N. Benitez, Instituto de Fisica de
Cantabria, Santander; J. Greiner, Astrophysikalisches Institut,
Potsdam; E. Costa, M. Feroci and L. Piro, Istituto di Astrofisica
Spaziale, Frascati; F. Frontera, Universita di Ferrara; E. Palazzi,
G. Pizzichini, and L. Nicastro, Istituto Tecnologie e Studio
Radiazioni Extraterrestri, CNR, Bologna; J. Heise and J. in't Zand,
Space Research Organization of the Netherlands, Utrecht; C.
Bartolini, A. Guarnieri, and A. Piccioni, Universita di Bologna; N.
Masetti, Universita di Padova; J. Gallego and J. Zamorano,
Universidad Complutense, Madrid; H. Pedersen, Copenhagen
Astronomical Observatory; and K. Birkle, MPIA, report that R-band
images of the field of GRB 970508 were obtained with the 2.2-m CAHA
telescope (+ CAFOS) at Calar Alto on May 9.128, 9.899, 10.872, and
11.868 UT.  The variable object noted by Bond (IAUC 6654) yielded
respective preliminary magnitudes (+/- 0.2) R = 20.8, 20.8, 19.6
and 20.4, perhaps indicating the beginning of the decline phase.  A
200-s spectrum (range 430-710 nm) obtained on May 10.879 shows a
blue continuum with no obvious strong emission lines.  A second
spectrum (350-800 nm) with 3600-s integration time was obtained on
May 11.895, suggesting the absence of strong emission and
absorption lines.  Images were also obtained in the U band with the
4.2-m William Herschel Telescope at La Palma on May 9.088, 10.056,
11.092, yielding preliminary magnitudes (+/- 0.3) 21.0, 20.5, and
20.3.  The object is therefore very blue and starlike in shape.


COMET 68P/KLEMOLA
     R-band CCD photometry by C. W. Hergenrother using the 1.2-m
refector at the F. L. Whipple Observatory:  Mar. 29.41 UT, 21.4;
May 3.33, 19.6; 3.34, 19.4.  The images are essentially stellar on
both nights but within 1" of the comet's expected position.


COMET 103P/HARTLEY 2
     R-band CCD photometry by Hergenrother:  May 2.47 UT, 19.6;
3.43, 19.5.  Co-adding three images (total integration time 900 s)
on May 3 shows a coma 5" across and a tail 8" long in p.a. 255 deg.

                      (C) Copyright 1997 CBAT
1997 May 11                    (6657)            Daniel W. E. Green