Central Bureau for Astronomical Telegrams
IAUC 6040: JUPITER AND 1993e
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Circular No. 6040
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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
JUPITER AND COMET 1993e
M. Kesteven and R. M. Price, Australia Telescope National
Facility (ATNF); I. de Pater, University of California at Berkeley;
G. A. Dulk, University of Colorado; and Y. Leblanc, Observatory of
Paris, write: "Observations of Jupiter were made in Australia at a
frequency of 1430 MHz: at Parkes (64-m dish, July 15-24) and with
the compact array of the ATNF (6 dishes of 22 m each, July 9-25).
These observations show an increase in the flux density of about
0.5 Jy from a pre-impact level of about 3.7 Jy. The major part of
the increase occurred during July 17-20; subsequently, the level
has been nearly steady. No change has been seen in the position
angle of the linear polarization. The images produced by the ATNF
compact array suggest that the increase in flux was due mainly to
an increase of brightness in the inner, synchrotron-emitting belts,
and not in the thermal emission of the disk."
W. M. Harris, University of Michigan at Ann Arbor (UM); T. A.
Livengood, Goddard Space Flight Center (GSFC); M. A. McGrath, Space
Telescope Science Institute; R. Prange, (IAS), Orsay; G. E.
Ballester, UM; S. Budzien, Naval Research Laboratory; M. Combi, UM;
C. Emerich, IAS; G. Fireman, GSFC; D. T. Hall, Johns Hopkins
University; K. L. Jessup, UM; A. Talavera, European Space Agency,
Vilspa; M. B. Vincent, UM; and L. Woodney, University of Maryland,
communicate: "We have analyzed spectra (range 115-195 nm) taken
with the International Ultraviolet Explorer (IUE) of the Io torus
and two impact regions during the recent impacts with Jupiter. Our
early analysis of Io torus spectra taken on July 20 indicates that
the torus was not significantly affected by initial phases of the
collisions. We also monitored the temporal evolution of the E and
G impact sites 40 min, 2 hr, and 4 hr after the impacts occured, as
they rotated with the planet. There are clear changes in the
spectrum consistent with the addition of new absorbers, including
possibly ammonia and some hydrocarbon species, along with an
enhancement in the strength of many previously-detected absorption
features. We also detect an average 50-percent drop in the
ultraviolet reflectivity of these regions across the IUE spectral
bandpass, as they move from the dawn to the dusk limb of the planet.
This result is consistent with the rapid development of a cloud of
high-altitude absorbing material with an area close to the size of
the IUE small (3") aperture, which at Jupiter is roughly equal that
of the earth."
1994 July 29 (6040) Daniel W. E. Green
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