Electronic Telegram No. 157
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
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COMET 9P/TEMPEL
    N. Biver, D. Bockelee-Morvan, P. Colom, J. Crovisier, and
A. Lecacheux, Observatoire de Paris; and G. Paubert, Institut de
Radioastronomie Millimetrique (IRAM), report:  "Comet 9P/Tempel
was observed with the IRAM 30-m radio telescope from May 4.8 to
9.0 UT.  The HCN J=3-2 and J=1-0 lines were detected with mean
integrated intensities of 111 +/- 8 and 31 +/- 4 mK km/s,
respectively.  Day-to-day variations in the HCN line intensities
are observed and reveal periodic variability in HCN production
from 5 to 10 x 10^{24} molecules/s.  The periodicity is 1.7 days,
consistent with the estimated nucleus rotational period.  H_2S and
CH_3OH were also marginally detected; CO, CS and H_2CO were searched
for and undetected.  The production-rate ratios, or their upper limits,
of these molecules relative to HCN are 5.5, 21, < 110, < 1.1, and < 17,
respectively.  All lines are blue-shifted, suggesting preferential
sunward outgassing."


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the formal IAU Circulars.

                         (C) Copyright 2005 CBAT
2005 May 26                      (CBET 157)               Daniel W. E. Green