Astronomy and Astrophysics – Astronomy
Scientific paper
Oct 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010dps....42.0301s&link_type=abstract
American Astronomical Society, DPS meeting #42, #3.01; Bulletin of the American Astronomical Society, Vol. 42, p.945
Astronomy and Astrophysics
Astronomy
1
Scientific paper
Comets are widely believed to be the most pristine objects available for detailed study remaining from the epoch of Solar System formation, and can be used as probes of the protoplanetary material incorporated at that time. Variations in chemical composition can indicate either differences in primordial conditions or evolutionary effects. The actual cause of specific differences in properties can be determined by statistical analyses of the chemical and orbital properties of a large number of objects. We are now completing a new uniform reduction and set of analyses of 34 years of narrowband photometry of the 165 comets that form the Lowell comet database. Cluster and principle component analyses reveals about 8-10 compositional groupings, several of which are sub-groups of the original carbon-chain depleted class as defined by A'Hearn et al. (1995). All evidence continues to indicate that the carbon-chain depleted class is primordial in nature and not associated with evolution. Unexpectedly, 4 comets are identified as being depleted in ammonia but not depleted in carbon-chain molecules. Details will be presented.
A narrowband photometry observing campaign of Comet 103P/Hartley 2 was just begun in support of the EPOXI flyby on November 4. Water production on July 12 (r=1.74AU) was 7e26 molecules/s. Based on observations from Hartley 2's 1991 and 1997 apparitions, and the assumption that there are no secular variations between apparitions, a significant seasonal effect exists with peak production taking place several weeks following perihelion. We estimate that the water production at perigee (Oct 20; 8 days prior to perihelion) will be about 2e28 molecules/s, while at the time of the EPOXI encounter (Nov. 4; 7 days following perihelion) we anticipate a value 50% greater, or 3e28 molecules/s. We will present additional on-going results.
This research is supported by NASA's Planetary Astronomy and Planetary Atmospheres Programs.
Bair Allison N.
Schleicher David G.
No associations
LandOfFree
A Compositional Taxonomy of Comets and Narrowband Photometry of EPOXI Target 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 A Compositional Taxonomy of Comets and Narrowband Photometry of EPOXI Target 103P/Hartley 2., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Compositional Taxonomy of Comets and Narrowband Photometry of EPOXI Target 103P/Hartley 2. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1121107