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IAUC 4773: 1987A; SU UMa; 1987 XXXVI

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                                                  Circular No. 4773
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 1987A IN THE LARGE MAGELLANIC CLOUD
     S. Dieters, P. Green, K. Hill, and R. Watson report:
"We made observations of SN 1987A on three runs with the 1-m
telescope of the University of Tasmania that provide upper
limits to the periodicity reported by Middleditch et al. (IAUC
4735).  The starting time, the duration, the sampling frequency,
and the 90-percent-confidence upper limit for each of these runs
are as follows:  Feb. 11.51 UT, 156 min, 6 kHz, mag 19.0; Mar. 1.52,
76 min, 9 kHz, mag 18.7; Apr. 4.50, 74 min, 9 kHz, mag 18.6.
Analysis involved averaging 4-million-point Fast Fourier Transforms
of overlapped data segments.  The limits refer to the 20-Hz band
on either side of the 1968-Hz reported periodicity.  No other
significant periodicities were noted."


SU URSAE MAJORIS
     This variable appears to be undergoing a supermaximum outburst,
as indicated by the following visual magnitude estimates:  Apr. 8.95
UT, [13.4 (P. Schmeer, Bischmisheim, W. Germany); 16.1, 12.1 (R.
Hayes, Worth, IL); 18.50, 11.5 (M. Iida, Nagano, Japan); 18.52, 11.7
(Iida); 19.1, 11.3 (Hayes); 19.87, 11.4 (Schmeer).  J. A. Mattei,
AAVSO, recommends that high-speed photometry be undertaken to search
for superhumps.


PERIODIC COMET PARKER-HARTLEY (1987 XXXVI)
     Ephemeris extension (cf. IAUC 4750) from orbital elements
on MPC 14460:

     1989 ET      R.A. (1950) Decl.     Delta      r       m1
     Apr. 24    10 21.03    + 3 55.3    3.562    4.185    17.0
     May   4    10 21.58    + 4 07.9
          14    10 23.57    + 4 11.8    3.885    4.235    17.2
          24    10 26.87    + 4 07.3
     June  3    10 31.32    + 3 54.8    4.230    4.284    17.5
          13    10 36.80    + 3 34.8
          23    10 43.14    + 3 08.2    4.571    4.333    17.7
     July  3    10 50.21    + 2 35.4
          13    10 57.89    + 1 57.3    4.884    4.381    17.9
          23    11 06.07    + 1 14.3
     Aug.  2    11 14.64    + 0 27.3    5.152    4.428    18.0


1989 April 20                  (4773)             Daniel W. E. Green

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