Circular No. 6798
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
     P. M. Woods, University of Alabama in Huntsville; C.
Kouveliotou, Universities Space Research Association; and G. J.
Fishman, Marshall Space Flight Center, NASA, report on behalf of
the BATSE Team: "GRB 971227 (IAUC 6796, 6797) was recorded as BATSE
trigger No. 6546.  It was a weak, short event of duration about 6 s
that exhibits two well distinguished peaks, separated by 2.5 s.
The burst fluence (above 25 keV) was 9.3 (+/- 1.4) x 10E-7 erg
cmE-2 and its peak flux (between 50 and 300 keV) was 3.3 +/- 0.2
photons cmE-2 sE-1.  The burst was not detected above 300 keV."


SUPERNOVA 1997ef IN UGC 4107
     P. Garnavich, S. Jha, R. Kirshner, and P. Challis, Harvard-
Smithsonian Center for Astrophysics; and D. Balam, University of
Victoria, report: "Recent CCD images of SN 1997ef obtained with the
Whipple Observatory 1.2-m telescope by P. Berlind, with the MDM
2.4-m telescope by J. Thorstensen, and with the Dominion
Astrophysical Observatory's 1.8-m Plaskett telescope indicate that
this object has begun to decline in brightness.  Visual magnitude
estimates relative to the star (V = 17.05) located 1' southwest of
UGC 4107:  Dec. 16.3 UT, 16.56; 27.3, 16.84; 28.3, 16.94.  Spectra
obtained at the Tillinghast telescope by Berlind and L. Macri, and
at the MDM 2.4-m telescope by Thorstensen, between Dec. 17 and 27
show that the rapid velocity shift seen in the major spectral
features has slowed.  After correcting for the redshift of UGC
4107, a number of peaks can now be identified at 397 nm (Ca II),
457 nm (?), 486 nm (H-beta), 547 nm (?), 587 nm (He I), 614 nm (?),
and 655 nm (H-alpha).  The H-alpha emission peak is rounded, while
the unidentified maxima have a triangular shape.  Currently, the
spectrum appears similar to the peculiar type-Ib supernovae 1988L
(Filippenko 1988, A.J. 96, 1941) and 1983I (Wheeler et al. 1987,
Ap.J. 313, L69), which also displayed broad maxima near the
wavelength of H-alpha.  These objects and SN 1997ef appear to be
extreme examples of massive stars that have lost all but a small
amount of hydrogen through mass loss."


COMET C/1997 D1 (MUELLER)
     Visual m_1 estimates:  Nov. 1.00 UT, 11.7 (M. Lehky, Hradec
Kralove, Czech Republic, 0.42-m reflector); Dec. 21.83, 12.1
(Lehky); 28.66, 13.4 (A. Pearce, Cadoux, W. Australia, 0.41-m
reflector).

                      (C) Copyright 1997 CBAT
1997 December 30               (6798)            Daniel W. E. Green