Central Bureau for Astronomical Telegrams
IAUC 4652: 1987A; 1988j; G 24-9
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Circular No. 4652
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
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
R. Chini, A. Gotz, C. G. T. Haslam, E. Kreysa, and P. G. Mezger,
Max-Planck-Institut fur Radioastronomie, Bonn, write: "During
Sept. 7-9 we monitored SN 1987A at a wavelength of 1.3 mm with the
Swedish/European Southern Observatory submillimeter telescope (+ MPIfR
bolometer) at La Silla. At the optical position we found an
average flux density of 29 +/- 4 mJy, integrated over a beam of
about 30". Possible contamination by underlying emission from the
LMC has been excluded by observing two adjacent positions 30" north
and south of SN 1987A where no signal was found above a limit of 4 mJy."
COMET MACHHOLZ (1988j)
H. Bohnhardt and V. Vanysek, Astronomical Institute, University
of Erlangen-Nurnberg, Bamberg, write: "Calculation of a
dynamical model of the dust tail of Comet Machholz 1988j reveals
that an anti-tail of this comet might be observable after its
perihelion passage until perhaps Oct. 10. Surface photometry
of this phenomenon compared with zodiacal-light brightness data is
desirable."
Total visual magnitude estimates: Sept. 3.51 UT, 6.0: (C. S.
Morris, near Mt. Wilson, CA, 20x80 binoculars); 3.79, 7.4 (R. H.
McNaught, Coonabarabran, N.S.W., 9x63 binoculars; 0.2-deg tail); 6.50,
7.0 (A. Hale, Las Cruces, NM, 0.41-m reflector); 6.78, 6.6 (D. A. J.
Seargent, The Entrance, N.S.W., 15x80 binoculars; in 0.25-m reflector,
0.2-deg tail in p.a. 248).
G 24-9
B. Zuckerman, Astronomy Department, University of California
at Los Angeles; and E. Becklin, Institute for Astronomy, University
of Hawaii, write: "On Sept. 3 we measured, with NASA's 3-m IRTF
telescope, the J (1.25 microns) and K (2.2 microns) magnitudes of
G 24-9, a white dwarf reported to undergo deep eclipses (IAUC 4125, 4648).
The measured magnitudes (J = 14.98, K = 14.76) are consistent with
radiation originating solely from the white dwarf. If the companion
object responsible for the eclipses has a radius greater than or
equal to that of Jupiter, then its effective surface temperature is
less than or approximately equal to 1200 K. Thus we agree
with Carilli and Conner (IAUC 4648) that the companion is substellar. For
a variety of reasons, the orbital period of the companion is likely
to be substantially less than the 1013-day maximum period quoted by
Carilli and Conner."
1988 September 14 (4652) Daniel W. E. Green
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