ISO Spectroscopic Observations of comets 22P/Kopff and 103P/Hartley 2

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

Two Infrared Space Observatory programmes (guaranteed time and open time) were devoted to high-resolution spectroscopic observations of short-period comets. 22P/Kopff was observed on October--December 1996 with the short- and long-wavelength spectrometers. Due to the weakness of the object, which was at 1.9 AU from the Sun at that moment, only the nu_3 ro-vibrational lines of water were detected, with SWS. They allowed a determination of the production rate of water in this comet and an analysis of its physical conditions. Comet 103P/Hartley 2 was observed close to its perihelion (at 1.04 AU from Sun and 0.82 AU from Earth) on January 1998 with the two spectrometers and ISOCAM. The bands of H_2O and CO_2 at 2.7 and 4.3 mu m are detected, with [CO_2]/[H_2O] = 20 %. The 2.7 mu m band of H_2O is observed with a high signal-to-noise ratio, which permits to evaluate the rotational temperature of water averaged within the field of view to 20 K, and its ortho-to-para ratio to ~ 2.7, corresponding to a spin temperature of 35 K. The 5--17 mu m spectrum of comet P/Hartley 2 observed with CAM-CVF shows the 9--12 mu m signature of silicates. A weak emission at 11.3 mu m (at a level of about 15 % of the continuum) indicates the presence of crystalline silicates. This is the first time crystalline silicates are found in a short-period comet. The ISO observations of the short-period, Jupiter-family comet P/Hartley 2, presumably originating from the Edgeworth-Kuiper belt, are to be compared to those of comet Hale-Bopp which came from the Oort cloud. They both show crystalline silicates, a high content of CO_2, and a low water ortho-to-para ratio. However, the dust-to-gas ratio of comet Hale-Bopp was much higher than that of P/Hartley 2.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

ISO Spectroscopic Observations of comets 22P/Kopff and 103P/Hartley 2 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with ISO Spectroscopic Observations of comets 22P/Kopff and 103P/Hartley 2, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and ISO Spectroscopic Observations of comets 22P/Kopff and 103P/Hartley 2 will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-813869

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.