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IAUC 4729: 1989A; 1987A; NSV 6708

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IAUC number 

                                                  Circular No. 4729
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN


SUPERNOVA 1989A IN NGC 3687
     R. H. McNaught, Siding Spring Observatory, provides the following
position from a Feb. 1.7 UT exposure with the Uppsala Southern Schmidt
telescope:  R.A. = 11h25m19.78, Decl. = +29 46'53.1 (equinox 1950.0);
offset from galaxy nucleus 21".4 west, 17".7 south.
     A. V. Filippenko, University of California at Berkeley, reports
that spectra (ranges 300-450 nm, 470-780 nm; resolution about 1 nm)
of SN 1989A (IAUC 4721, 4724) were obtained by S. Veilleux and H.
Tran, University of California at Santa Cruz, on Jan. 31 UT with a
Cassegrain CCD spectrograph on the Shane 3-m reflector at Lick
Observatory.  A verbal description of the spectra confirms that SN
1989A is a type-Ia object past maximum brightness.
     Visual magnitude estimates by R. Monella, Covo, Italy:
Feb. 1.94 UT, 13.8; 2.05, 13.7.


SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
     G. Burki and N. Cramer, Geneva Observatory, communicate:  "The
Geneva photometric monitoring from La Silla reveals that the
luminosity curves in the V and B bands have started to decrease
more slowly after approximately 1988 Oct. 15.  At this date,
these curves exhibited an inflexion which is not detected on the
U curve.  The behavior of the V and B curves could be interpreted as
the effect of an additional energy source, such as the expected
central pulsar or as the increasing relative contribution of slower
decaying radionuclides.  It is now necessary to correct the visible
photometric measurements for the increasing relative importance of
the close companion stars of the supernova progenitor.  On 1989 Jan.
17, we observed U = 11.72, B = 10.81, V = 11.56, leading to 11.89,
10.90, 11.63, respectively, for the corrected magnitudes."


NSV 6708
     Visual magnitude estimates (cf. IAUC 4679):  1988 Nov. 28.73 UT,
12.8 (R. H. McNaught, Coonabarabran, N.S.W.); 1989 Jan. 12.71, 9.8
(McNaught); 14.69, 9.4 (McNaught); 15.63, 9.3 (McNaught); 17.72, 9.2
(P. Williams, Heathcote, N.S.W.); 22.20, 8.3 (V. F. de Assis Neto,
Sao Francisco de Oliveira, Brazil).


1989 February 3                (4729)             Daniel W. E. Green

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