[IAUC] CBET 2781: 20110807 : COMET C/2010 X1 (ELENIN)

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                                                  Electronic Telegram No. 2781
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2010 X1 (ELENIN)
     M. Drahus, University of California at Los Angeles; Bin Yang, University
of Hawaii; and J. Hoge, Joint Astronomy Centre, report the detection of HCN
in comet C/2010 X1 on July 30 when at heliocentric distance r = 1.07 AU.
Observations between July 30.153 and 30.249 UT at the James Clerk Maxwell
Telescope show the J = 4-3 line with area about 0.1 K km/s in antenna
temperature scale.  Assuming an isotropic production of gas at velocity 0.5
km/s and a Boltzmann distribution of energy levels at 50 K, the derived HCN
production rate is 1.5 x 10**25 molecules/s, comparable to the mean level
measured in comet 103P/Hartley at the same heliocentric distance in late
2010 (Drahus et al. 2011, Ap.J. 734, L4).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2011 CBAT
2011 August 7                    (CBET 2781)              Daniel W. E. Green