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IAUC 6791: GRB 971214; 103P

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                                                 Circular No. 6791
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)
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GRB 971214
     A. Diercks and E. W. Deutsch, University of Washington; R.
Wyse, The Johns Hopkins University; G. Gilmore, Cambridge
University; C. Corson, Apache Point Observatory; F. J. Castander,
University of Chicago; and E. Turner, Princeton University, write:
"We confirm the fading optical transient reported by Halpern et al.
on IAUC 6788, which we measure to be at R.A. = 11h56m26s.35, Decl.
= +65o12'00".7 (equinox 2000.0).  The object was observed to fade
by about 1.6 mag in R over 24 hr in images taken by Corson,
Gilmore, and Wyse with the ARC 3.5-m telescope at Apache Point:
Dec. 15.51 UT, R = 22.1 +/- 0.1; 16.52, 23.7 +/- 0.3.  No other
object brighter than R about 21.5 was observed to vary.  Magnitudes
and positions were calculated based on photometry and astrometry of
two stars measured in the 'Automatic Plate Measuring' (APM) survey
(Maddox et al. 1990, MNRAS 243, 692); neither star varied (within
uncertainties) over the 24-hr period, their position end figures
and magnitudes being 25s.75, 11'35".7, R = 20.10 +/- 0.01; 34s.22,
11'44".2, 20.78 +/- 0.03.  Estimated zero-point errors in
converting from the APM R_F band to the R band are about 0.3 mag.
Our R-band observations on Dec. 15 and 16 were approximately
coincident with the reported MDM I-band detections by Halpern et
al., giving a color for this object of R-I = +1.0 +/- 0.4.  Within
the quoted errors, the color is constant during the fading.  Images
are available at
http://www.astro.washington.edu/deutsch/misc/grb971214/."
     Castander, Wyse, Gilmore, Corson, Diercks, and Deutsch; D. Q.
Lamb, University of Chicago; and Turner report an additional
magnitude from six 10-min exposures (using Landolt standard star
104239), indicating that the observed R-band fluxes are consistent
with a power-law decay in time:  Dec. 17.51 UT, R = 24.4 +/- 0.5.
The first of the unvarying stars noted above was measured at R =
20.14 +/- 0.02 at this time.
     Regarding their item on IAUC 6788, N. Itoh et al. note that
their faint object is near HD 103690; though the position accuracy
is limited by poor seeing, they provide the following improved
position end figures:  25s.6 +/- 0s.2, 55".7 +/- 0".1.  Also, on
line 1, for  done  read  down


COMET 103P/HARTLEY 2
     Total visual magnitude estimates by M. Lehky, Hradec Kralove,
Czech Republic (L = 0.42-m reflector; B = 25x100 binoculars):  Oct.
19.76 UT, 11.1 (L); 21.75, 11.6 (L); 31.84, 10.9 (L); Nov. 4.74,
10.7 (L); 10.73, 10.7 (L); 20.71, 9.7 (B); Dec. 14.74, 9.1 (B);
16.72, 8.4 (B).

                      (C) Copyright 1997 CBAT
1997 December 18               (6791)            Daniel W. E. Green

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