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Ge/Ay133

What can comets tell us about the early S.S.?. Comet Hale-Bopp. Deep Impact (Comet Tempel 1). Ge/Ay133. Sharp drop off suggests a min ~1.7 x 10 4 AU, unlikely to be bound over S.S. history?. How are bodies placed into the Oort Cloud? Jupiter most important dynamically,

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Ge/Ay133

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  1. What can comets tell us about the early S.S.? Comet Hale-Bopp Deep Impact (Comet Tempel 1) Ge/Ay133

  2. Sharp drop off suggests amin~1.7 x 104 AU, unlikely to be bound over S.S. history?

  3. How are bodies placed into the Oort Cloud? Jupiter most important dynamically, but Neptune is the most efficient.

  4. What forces are most important in perturbing the Oort Cloud? versus ?

  5. What are comets made of? Dust/ice~1 HH46 W33A Hale-Bopp Water 100 100 100 CO 20 1 23 CO2 30 3 6 CH4 4 0.7 0.6 H2CO … 2 1 CH3OH 7 10 2 HCOOH 2 0.5 0.1 NH3 9 4 0.7 OCS … 0.05 0.4 Spitzer+Keck studies are mapping out both gas phase & grain mantle composition, comparable to that found in massive YSOs, comets. How are these ice components determined?

  6. For species with dipole moments, use rotational spectra:

  7. ISO spectra: Infrared spectroscopy gives access to pivotal non-polar species (CO2, CH4), and in many cases, water. Water “spin” temp.~25 K

  8. Ground-based data can also provide constraints, on a much larger number of comets, but must fight through the Earth’s atmosphere!

  9. Isotope ratios? D/H most important to date…

  10. What about “exo-zodii’s? That is, dust in ~1 AU range? Rare! Only one convincing case so far, in large aperture searches. Need to get closer to the star…. Beichman et al., ApJ, 626, 1061

  11. Astronomically, we only have spectroscopy to probe the dust.

  12. IDPs can be analyzed in the lab! Comet dust assembled from sub- micron sized components.

  13. Samples of known provenance!

  14. Crystalline silicates do seem to be formed in the inner parts of disks. How to transport to comet-forming zone (>10 AU)?

  15. FEBs = Falling Evaporative Bodies See transient redshited absoprtion against stellar continuum. Evaporating comets? For the brightest sources (e.g. b Pic), you can actually image things like Na I line emission and map the disk.

  16. Sun-grazing comets as seen by SOHO (look for “metals”): http://sohowww.estec.esa.nl/bestofsoho/Movies/movies2.html#comets

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