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IAUC 6800: GRB 971227; 1997ei

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                                                 Circular No. 6800
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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Phone 617-495-7244/7440/7444 (for emergency use only)


GRB 971227
     A. J. Castro-Tirado and J. Gorosabel, Laboratorio de
Astrofisica Espacial y Fisica Fundamental, Madrid; J. Greiner,
Astrophysikalisches Institut, Potsdam; M. R. Zapatero-Osorio,
Instituto de Astrofisica de Canarias, Tenerife; and E. Costa,
Istituto di Astrofisica Spaziale, Frascati (on behalf of the
BeppoSAX team) report:  "Following the detection of GRB 971227 by
BeppoSAX and BATSE (IAUC 6796, 6798), R-band images were obtained
by Y. Aguilar and R. Kohley (Sternwarte der Universitat, Bonn) with
the 2.2-m CAHA telescope (+ CAFOS) at the German-Spanish Calar Alto
Observatory.  Only the image taken on Dec. 27.91 UT includes the
entire error box of 1SAX J1257.3+5924, presumably the GRB 971227
x-ray afterglow (IAUC 6797).  An object with R = 19.5 (preliminary
magnitude) at the edge of the 16' field-of-view, and inside the
1SAX J1257.3+5924 error box, is seen on the Dec. 27 image at R.A. =
12h57m10s.6, Decl. = +59o24'43" (equinox 2000.0; uncertainty +/-
3"), but it is not present on images taken on Dec. 30 at Loiano
(see below), to a limiting magnitude of R = 20.5.  An
identification chart can be obtained via anonymous ftp at
laeff.esa.es under /pub/users/ajct/grb971227.  Deeper observations
are encouraged in order to confirm whether this is the optical
counterpart of GRB 971227."
     C. Bartolini, A. Guarnieri, M. Lolli, A. Piccioni, and F.
Zavatti, Universita di Bologna, communicate:  "The object proposed
by Castro-Tirado et al. (above) is undetectable on our R frames on
Dec. 30.16, which were taken at the 1.5-m telescope of the Bologna
Astronomical Observatory in Loiano.  The object was therefore
fainter than R = 20.5 (mag limit of the images, preliminary value).
Data reduction is in progress. Deeper imaging is highly recommended."


SUPERNOVA 1997ei IN NGC 3963
     K. Ayani, Bisei Astronomical Observatory (BAO); and H.
Yamaoka, Kyushu University, report:  "A spectrum of SN 1997ei was
obtained with the BAO 1.01-m telescope on Dec. 28.8 UT, from which
we confirm the classification (type Ia) reported on IAUC 6796.
However, a Si II feature near 615 nm is rather shallow compared
with typical (bright) type-Ia supernovae.  A Si II feature around
580 nm is also visible.  These features suggest that SN 1997ei is
a somewhat peculiar type-Ia object, probably fast-declining and
sub-luminous (Nugent et al. 1995, Ap.J. 455, L147)."

                      (C) Copyright 1997 CBAT
1997 December 30               (6800)            Daniel W. E. Green

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