EDP Sciences
Free access
Issue
A&A
Volume 422, Number 1, July IV 2004
Page(s) L19 - L21
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20040190


A&A 422, L19-L21 (2004)
DOI: 10.1051/0004-6361:20040190

Letter

Rosetta target comet 67P/Churyumov-Gerasimenko

Postperihelion gas and dust production rates
R. Schulz1, J. A. Stüwe2 and H. Boehnhardt3

1  ESA Research and Scientific Support Department, ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands
    e-mail: Rita.Schulz@rssd.esa.int
2  Sterrewacht Leiden, Postbus 9513, 2300 RA Leiden, The Netherlands
    e-mail: stuwe@strw.leidenuniv.nl
3  Max-Planck-Institute for Aeronomy, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany
    e-mail: hboehnha@linmpi.mpg.de

(Received 19 March 2004 / Accepted 5 June 2004)

Abstract
The evolution of the activity and composition of the coma of ROSETTA target comet 67P/Churyumov-Gerasimenko was studied along its postperihelion orbit from 2.29 AU to 3.22 AU. The comet had a major drop of activity between 2.5 AU and 2.9 AU, which manifested most obviously in its light curve (the brightness decreased by 3 mag), but is also confirmed by the production rates derived from spectrophotometric measurements. The strong decrease of activity indicates a change in the outgassing behaviour of the nucleus and might be due to water sublimation becoming less efficient. The spectrophotometric measurements at 2.9 AU show that the coma is at least slightly depleted in C 2 with respect to CN.


Key words: comets -- Rosetta -- 67P/Churyumov-Gerasimenko -- production rates

Offprint request: R. Schulz, Rita.Schulz@rssd.esa.int




© ESO 2004