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THE ASTRONOMER Electronic Circular No 872 1994 Aug 13 22.00 UT
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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COMET MACHHOLZ (1994o)
Donald E. Machholz reports his visual discovery of a comet.
The following observations are available:
1994 UT R.A. (2000) Decl. m1 Observer
Aug. 13.4215 4 12.9 +62 48 10 Machholz
13.80190 4 20 30.42 +62 37 18.1 Kojima
13.80304 4 20 31.66 +62 37 18.1 "
13.80431 4 20 33.44 +62 37 18.6 "
13.80535 4 20 35.32 +62 37 11.6 "
D. E. Machholz (Colfax, CA). 0.25-m reflector. Comet diffuse with
little condensation; coma diameter perhaps 3'-4'.
T. Kojima (YGCO Chiyoda Observatory). 0.25-m reflector + CCD. Poor
conditions in twilight. Comet diffuse with condensation.
Communicated by S. Nakano, Sumoto, Japan.
IAUC 6053
JUPITER AND COMET 1993e
G. Bjoraker, Goddard Space Flight Center, NASA; and T. Herter,
S. Stolovy, G. Gull, and B. Pirger, Cornell University, write: "We
have detected cometary water in the fireball of fragments G and K
immediately after the plume became visible to observers on Earth.
The observations were performed using the Kuiper Echelle Grating
Spectrometer (spectral resolving power 9000; 5" slit) on the Kuiper
Airborne Observatory. The G fireball was observed at about July
18.323 UT; the K fragment fireball was observed on July 19.444.
Three H2O lines were observed in emission for both the G and K
fireballs at the following wavelengths: 7.7136, 7.7118, and 7.7090
microns. Numerous jovian 12CH4 and 13CH4 lines were observed in
emission across our bandpass (7.671-7.722 microns). This serves as
a thermometer of Jupiter's stratosphere, sounding the 1-microbar to
10-millibar levels. The radiance in the jovian CH4 lines increased
by a factor of about 25-30 between the pre-crash level and the peak
of the fireball. The CH4 lines were observed to decay over the
next 2 hr. The three H2O lines have a distinctively different time
behavior: they essentially disappear over a 30-min period. Very
high temperatures (T > 500 K) are required to observe these H2O
transitions. The observing geometry, high temperature, and short
time scale for the disappearance of these H2O lines favor a cometary
(rather than jovian) source. This, in turn, would confirm that
P/Shoemaker-Levy 9 was a comet and not an asteroid."
IAUC 6053
Martin Mobberley