Circular No. 6806
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)
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Phone 617-495-7244/7440/7444 (for emergency use only)
 

GRB 971227
     J. Mendez, Isaac Newton Group (ING), La Palma, and University
of Barcelona (UB); P. Ruiz-Lapuente, UB; and N. Walton, ING, report: 
"We used the 2.5-m Isaac Newton Telescope at the Observatorio del
Roque de los Muchachos to survey the field of GRB 971227, using the
Wide Field Camera in the (RGO) I band.  We did not detect the GRB
afterglow previously reported (IAUC 6800), down to a limiting mag I
= 22, ten days after the burst (Jan. 6.1 UT).  We note an extended
object (possibly a faint galaxy) located 15" west and 3" south of
the position of the GRB reported by Castro-Tirado et al. (ibid.).
Our images are available at http://www.ing.iac.es/~jma/grb971227.gif."


V1333 AQUILAE
     C. Chevalier and S. A. Ilovaisky, Observatoire de Haute
Provence (OHP), write:  "CCD photometry of the optical counterpart
of the recurrent x-ray transient Aql X-1 has been obtained with the
1.2-m OHP telescope from 1997 Feb. 19 through Nov. 23.  Analysis of
the data taken when the source was bright (29 nights during Aug.
6-Sept. 25) shows the presence of the 19-hr modulation reported
previously by us (1991, A.Ap. 251, L11).  When combined with data
taken during the 1995 and 1996 bright states, which also show the
modulation, the periodogram of the entire data set (484 frames
taken on 59 nights) yields a strong and unique peak with period
0.789 498 +/- 0.000 010 day (18.9479 +/- 0.0002 hr).  An
independent time analysis of data taken during quiescence in 1997
(112 frames taken on 27 nights during Mar. 31-July 15 and Oct. 8-
Nov. 23) shows a peak at the same value of the period, to within
0.02 percent, as well as a smaller peak at one-half this period.
The folded lightcurve is thus double-waved, with unequal minima and
slightly unequal maxima.  The deepest minimum is in excellent phase
agreement with the single bright state lightcurve minimum.  We
conclude that both the quiescent state and the bright state
modulations are directly related to orbital motion." 


COMET 55P/TEMPEL-TUTTLE
     Visual m_1 magnitude estimates:  Jan. 2.49 UT, 10.8 (C. E.
Spratt, Victoria, BC, 0.20-m reflector); 4.19, 10.0 (G. Comello,
Roden, The Netherlands, 0.30-m reflector); 8.12, 9.7 (K. Hornoch,
Lelekovice, Czech Republic, 0.13-m reflector); 10.43, 9.0 (J.
Bortle, Stormville, NY, 20x80 binoculars); 11.30, 9.0 (P. Creed,
Massillon, OH, 0.20-m reflector).

                      (C) Copyright 1998 CBAT                    
1997 January 13                (6806)            Daniel W. E. Green