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IAUC 4426: 1987J, 1987K; PSR 1951+32; 1987A; 1987p

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IAUC number 

                                                  Circular No. 4426
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM    Telephone 617-495-7244/7440/7444


SUPERNOVAE 1987J AND 1987K
     C. Pollas reports his discovery of a probable supernova,
designated SN 1987J, on plates exposed with the CERGA 0.9-m Schmidt
telescope at Caussols.  The object is located 18" west and 2" south
of the center of ESO 601-26 (R.A. = 22h07m39s, Decl. = -19 07.1, equinox
1950.0).  The following magnitudes were derived:  July 25.083 UT,
mpv = 17.4; 28.031, mpv = 17.2; 29.038, U > 18.5; 29.094, B = 18.3.
     C. Pennypacker, University of California at Berkeley, and the
Berkeley Automated Supernova Search Team report the discovery at
Leuschner Observatory on July 28 of a 15th-magnitude SN (designated
1987K) located 22" west and 5" north of the center of NGC 4651 (R.A. =
12h41.2, Decl. = +16 40', equinox 1950.0).  The object was also
observed on July 29; on July 13 it was fainter than mag about 17.


PSR 1951+32
     A. S. Fruchter and J. H. Taylor, Princeton University; and D.
C. Backer, T. R. Clifton, and R. S. Foster, University of California,
Berkeley, write:  "Follow-up observations of PSR 1951+32 (cf.
IAUC 4422) have now been made at Arecibo.  From data taken at 1408
MHz on six nights between July 17 and 28, the following parameters
were obtained: period = 0.039 529 751 9 +/- 0.000 000 000 2 s; period
derivative = (6.0 +/- 0.3) x 10E-15 s/s; period epoch = JD 2446993.66;
dispersion measure = 45 +/- 2 cmE-3 pc; pulse width at 50 percent =
3.0 ms; mean flux density = 1.0 +/- 0.3 mJy.  The period derivative
is surprisingly small (factors of 70 and 20 less than that of the
Crab pulsar and the Vela pulsar, respectively).  We note that the
period and dispersion measure presented in IAUC 4422 were derived
from timing observations at Arecibo on July 17."


SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
     Visual magnitude estimates:  July 22.36 UT, 4.5 (A. Beresford,
Adelaide, S. Australia); 23.82, 4.6 (R. H. McNaught, Siding Spring
Obs.); 25.47, 4.8 (D. A. J. Seargent, The Entrance, N.S.W.); 26.60,
5.0 (Seargent); 28.73, 4.7 (McNaught); 29.38, 4.7 (Beresford).


PERIODIC COMET BORRELLY (1987p)
     Total visual magnitude estimate by A. Pearce and M. Clark,
Perth, W. Australia (0.32-m reflector):  July 25.82 UT, 13.8.


1987 July 30                   (4426)            Daniel W. E. Green

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