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THE ASTRONOMER Electronic Circular No 861      1994 July 19 21.20UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England. Telephone/FAX(0256)471074 Int:+44256471074
INTERNET: GMH at AST.STAR.RL.AC.UK  or    GMH at GXVG.AST.CAM.AC.UK
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PERIODIC COMET SHOEMAKER-LEVY 9 (1993e)/COLLISION WITH JUPITER
Fragment C
Brian Manning, Stakenbridge, UK reports a probable visual
observation of the spot left by the impact of Fragment C. It was
seen a little west of the central meridian and almost due south
of the shadow transit spot of Io. It was observed on 1994 July 17
and was best seen between 20.00-20.15UT. Instrument 0.26-m reflector
x150. The spot was very small and not easily seen.
Andy Stephens, Bristol, UK also reports seeing a spot visually
on July 17 between 20.21-20.42UT with a 0.254-m SC x189 (no filter).
It was easier in daylight and twilight but more difficult when the
planet was in a darker sky. The patch was not so intense as the
shadow transit (presumed Io? Editor).
John Sanford, Costa Mesa, California, USA has faxed a report
indicating he has detected two spots on July 18 at 05.00UT using
a 0.30-m Ritchey-Chretien. The spots (A and C-Ed?) imaged dark
with integrated light and a Starlight Xpress CCD camera. About one
second integrations were required at the image scale used with
Jupiter taking up about 0.5 of the frame with 3m focal length plus
3x telextender negative lens.
Fragment F
Further reports, received in part via the SL9 message centre,
indicate considerable confusion concerning the detection of the
impact of fragment F = 16.  This had been predicted to occur 95
percent of a jovian rotation after the E impact, but because the F
prediction was early this impact point almost coincided with the E
impact point, which was still very active.  Nevertheless, it appears
that the plume from the F impact was observed at the European
Southern Observatory, but only at wavelengths of 5-12 microns.
B. Mosser, T. Livengood and H. U. Haufl made the detection on
July 18.060 UT, and the plume remained at the limb for more than
20 min. IAUC 6026
Fragment G
As expected, the impact of fragment G = 15 was the most spectacular
so far, and the first report received was that from H. Nguyen
at the South Pole.  The University of Chicago's South Pole Infrared
Explorer (SPIREX), a 0.60-m telescope operating mainly at 2.36
microns, reported this event on July 18.320 UT. CASPIR 2.34-micron
images and IRIS K-grism cubes showed an initial flash on July 18.315
(attributed to fragment G2 = 15b), half as bright as the C-impact
site, brightening by about a factor of four on July 18.316 and then
stable until 18.319, at which time the G (or G1 = 15a) impact
saturated the detectors and produced brilliant diffraction spikes.
After July 18.340 the G impact site had decreased in brightness in K
to about four times  that of the C impact site, but it was
detectable in IRIS bands from J to M, as well as in the visible.
S. Nakano, Sumoto, Japan, communicates that many amateur astronomers,
some using telescopes of aperture only 0.10 m, have visually detected
the G impact site; according to A. Nakamura and K. Ito the region
was larger than the Great Red Spot and very dark, with a wave to the
west like that of site A. IAUC 6026
Guy M Hurst







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Date: Wed, 20 Jul 1994 21:43:09 +0100 (BST)