Central Bureau for Astronomical Telegrams
IAUC 6029: 1993e
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 6030
.dvi or
.ps format.
Circular No. 6029
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)
PERIODIC COMET SHOEMAKER-LEVY 9 (1993e)
Z. Sekanina, P. W. Chodas and D. K. Yeomans, Jet Propulsion
Laboratory, communicate: "Between July 22 and at least the last week
of September Jupiter will be bombarded by the debris that populated
the comet's west-southwestern trail. Between July 27 and Sept. 22
the impact sites will be located on the planet's near side as viewed
from the earth. The collisions will occur at a decreasing pace both
in terms of the event rate and the characteristic size of the
individual particulates. We estimate that this debris consists of
centimeter- to subkilometer-sized fragments, so that explosive
phenomena triggered by the impact events will be much less powerful
than those associated with impacts of the major fragments. Yet,
searches for both possible individual events and any collective effects
are encouraged. Our model predicts that the jovicentric latitude of
the impacts will vary from -44 deg in late July to +42 deg in late
September. The earth-Jupiter-impact site angle will reach its
minimum of 69 deg on Sept. 3, at which time the impact geometry will be
the most favorable for earth-based observers. All impacts will be near
Jupiter's morning (eastern) limb. After Sept. 22 the impact sites
move back to the far side, but by that time the impact rate will have
diminished considerably and Jupiter will be approaching conjunction
with the sun."
Z. Pujic, University of Queensland, Brisbane, reports that ten
observers mainly using a 0.32-m reflector (383 x) independently noted the
K impact plume, 5" high x 3" wide, visually for 10 min beginning July
19.437 UT; three observers had independently noted the G impact plume,
8" high x 5" wide, visually for 10 min beginning July 18.321. After
July 19.463 an indentation was visible at the K site, and a dark spot
gradually appeared at the center of this feature; well on to Jupiter's
disk by July 19.483, the spot was then seen to be surrounded by a
collar of dark matter.
Early reports via the SL9 message center of the impact of fragment
L = 11 included a detection of the plume by M. Skrutskie and S. Aas with
the NICMASS infrared camera at the University of Massachusetts on July
19.928 UT at 2.23-2.29 microns. The Calar Alto Observing Team (cf.
IAUC 6023) first detected the impact at 2.3 microns on July 19.926; rapid
brightening occurred after 19.928, and by 19.929 the L site was six times
brighter than the K site at that time. O. L. Chaves saw the plume
visually with the 0.46-m refractor at the Observatorio Nacional at
Rio de Janeiro on July 19.933, reaching its maximum extent on 19.935.
1994 July 19 (6029) Brian G. Marsden
Read IAUC 6030
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
