Circular No. 6671
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)
URL http://cfa-www.harvard.edu/cfa/ps/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)


GRB 970508
     A. I. Kopylov, Special Astrophysical Observatory, and his
colleagues (cf. IAUC 6663) write:  "Further optical multicolor
observations of Bond's variable object (IAUC 6654) were obtained
with 6-m telescope.  Our preliminary reduction shows the following
Johnson and Kron-Cousins magnitudes on May 22.00 UT:  B > 22.3, V =
22.9 +/- 0.5, R_c = 22.2 +/- 0.15, I_c = 21.7 +/- 0.3.  The object
has continued to fade; over 11 days, a power law with a slope of
-1.1 is a good approximation of its brightness decay in the R band."


SUPERNOVA 1997cn IN NGC 5490
     Corrigenda.  On IAUC 6667, line 7, for 1991,  read  1996,
On line 12, for  km/s) in comparison to read  km/s), comparable to


COMET C/1995 O1 (HALE-BOPP)
     Extension to ephemeris on IAUC 6547 (elements MPC 29568):

1997 TT     R. A. (2000) Decl.   Delta     r    Elong. Phase    m1
June  1     5 54.43   +10 05.0   2.272   1.388   22.3   16.1    1.2
      6     6 03.19   + 7 59.1   2.342   1.449   21.7   15.0    1.5
     11     6 11.49   + 5 57.8   2.408   1.510   21.5   14.3    1.7
     16     6 19.40   + 4 00.4   2.470   1.573   21.8   13.9    1.9
     21     6 26.97   + 2 05.9   2.528   1.636   22.4   13.7    2.2
     26     6 34.26   + 0 13.6   2.583   1.699   23.4   13.8    2.4
July  1     6 41.28   - 1 37.1   2.633   1.762   24.7   14.0    2.6
      6     6 48.06   - 3 26.8   2.680   1.825   26.3   14.3    2.8
     11     6 54.62   - 5 16.0   2.723   1.889   28.2   14.7    2.9
     16     7 00.96   - 7 05.2   2.763   1.952   30.2   15.2    3.1
     21     7 07.10   - 8 54.7   2.799   2.015   32.3   15.6    3.3
     26     7 13.03   -10 44.8   2.832   2.078   34.6   16.1    3.4
     31     7 18.76   -12 35.8   2.863   2.141   37.0   16.6    3.6
Aug.  5     7 24.28   -14 27.9   2.891   2.203   39.4   17.0    3.7
     10     7 29.58   -16 21.4   2.916   2.266   41.9   17.4    3.9
     15     7 34.66   -18 16.4   2.939   2.328   44.5   17.7    4.0
     20     7 39.50   -20 12.9   2.961   2.389   47.1   18.1    4.1

                      (C) Copyright 1997 CBAT
1997 May 29                    (6671)            Daniel W. E. Green