Spectral observations in the 2.5-12 Î¼m range of comet 103P/Hartley 2 were performed on 1 Jan. 1998 by the ISOPHOT instrument, on board the Infrared Space Observatory. The obtained spectrum evidences intense bands at 2.66 and 4.26 Î¼m, attributable to H 2O and CO 2, respectively. The derived molecular production rates are Q(H 2O) = (3.1 Â± 0.2) Ã 10 28 molec. s -1 and Q(CO 2) = (2.5 Â± 0.3) Ã 10 27 molec. s -1. This leads to a CO 2/H 2O abundance ratio of â¼ 8%, showing that P/Hartley 2 is a relatively CO 2 abundant comet, with respect to IP/Halley and several other comets. A feature has been detected at 3.69 Î¼m, whose attribution is rather puzzling. The long wavelength part of the spectrum is well fitted by a black-body profile at 285 K colour temperature. No significant silicate emission feature around 10 Î¼m is observed, within observation errors.
|Titolo:||Infrared spectral observations of comet 103P/Hartley 2 by ISOPHOT|
|Data di pubblicazione:||1999|
|Appare nelle tipologie:||1.1 Articolo in rivista|