Central Bureau for Astronomical Telegrams
IAUC 4532: 1987A; 1987O, 1987P; GX 339-4
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Circular No. 4532
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
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
F. Makino, Institute of Space and Astronautical Science,
Tokyo, reports for the Ginga Team: "We have been monitoring the x-
ray intensity of SN 1987A from Ginga. The flux values obtained so
far are given below. These values are corrected for the energy-
dependent detection efficiency of the Ginga detector, for aspect
and for contributions of nearby sources. Errors include statistical
errors as well as systematic errors due to the flux variation
of LMC X-1 and also the background fluctuations. There follow for
each date of observation the x-ray fluxes (units of 10**-12 erg cm-2)
in two energy ranges 6-16 keV and 16-28 keV, respectively (errors
given parenthetically): 1987 July 4, 12.6 (8.9), 24.7 (7.7); Aug.
3, 17.8 (3.3), 25.4 (7.6); Sept. 3, 21.7 (3.2), 32.0 (9.2); Sept.
28, 13.4 (3.4), 25.4 (9.5); Nov. 4, 21.7 (5.4), 36.6 (16.7); Dec.
10, 17.2 (3.8), 24.6 (9.1); Dec. 26, 9.3 (3.0), 29.4 (7.5); 1988
Jan. 7, 35.1 (4.5), 52.9 (10.8); Jan. 12, 46.6 (3.4), 53.5 (8.7)."
Visual magnitudes by A. C. Beresford, Adelaide, S. Australia:
Jan. 15.46 UT, 6.4; 16.50, 6.3; 17.46, 6.4; 18.47, 6.3; 19.50, 6.3.
SUPERNOVAE 1987O AND 1987P
C. Pollas, Caussols Observatory, reports revised magnitude
estimates (cf. IAUC 4521, 4523, 4525) from photographic plates for SN
1987O: Dec. 20, 17.6 (15301 emulsion); Dec. 28, U [18.5; Dec. 29, B
= 18.5. Magnitudes for SN 1987P: 19, 18.5, and 17.8, respectively.
GX 339-4
W. B. Honey and P. A. Charles, Oxford University; J. R.
Thorstensen, Dartmouth College; and R. H. D. Corbet, Institute of
Space and Astronautical Science, Tokyo, report a periodic modulation
in the brightness of the optical counterpart of the x-ray
source GX 339-4 in its low state (IAUC 4383). The modulation has
a period of 0.618 +/- 0.004 day (14.8 hr) and a half-amplitude of
0.20 +/- 0.04 mag in both the R and I bands. 283 usable CCD frames
were obtained during 1987 July 18-30 with the CTIO 1.5-m and SAAO
1-m telescopes. Point-spread fitting techniques were used to
deconvolve the x-ray star from its accidental companion. The 1986
June-July high-state data obtained by Corbet et al. (1986, MNRAS
227, 1055) corroborate the 0.62-day period.
1988 January 19 (4532) Brian G. Marsden
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