Strategy for the Detection and Study of Other Planetary Systems and Extrasolar Planetary Materials 1990-2000 (1990) / Chapter Skim
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6. Future Investigations of Precursor Planetary Systems
6. Future Investigations of Precursor Planetary Systems
Pages 57-66
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From page 57... ...
The last two were identified in Chapter 3 as the immediate precursors to evolved stellar systems, and it is in their vicinity that we can expect to observe the early stages of planet formation. The study of dust is singled out for special treatment because dust is ubiquitous and plays a unique role as a tracer of many physical 57
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From page 58... ...
Dust grains of interplanetary origin can be collected in the atmosphere or in near-Earth space and studied in the laboratory to determine composition, mineralogy, and optical properties. COMPLEX has reviewed a catalog of infrared spectra taken of individual, microscopic dust particles that display a multiplicity of characteristic features relatable to their separateh,r determined intrinsic properties and is convinced of the efficacy of techniques available for the establishment of ground truth.
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From page 59... ...
LABORATORY STUDY OF INTERSTELLAR MATERIALS Infrared spectra of interstellar grains are complex and difficult to interpret unambiguously because there may be several constituents as well as contn~utions to the shape of a given spectral feature from the lattice structure of the solid matenal. Thus it is advisable to have laboratory ground truth analysis of candidate grain samples based on the wide range of in situ measurement techniques currently available.
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From page 61... ...
Recently developed ion microprobe techniques have provided isotopic analyses of carbon and hydrogen in grains in the 10-~2-g range. In addition to the ion probe, newer developing techniques include accelerator mass spectromeny, multicollector mass spectromeDy, synchrotron x-ray microprobe analysis, ultrasensitive organic analysis, and high-resolution analytical electron microscopy.
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From page 62... ...
It will therefore be necessary to supplement the unaging surveys by instruments that might be expected to reveal the presence of protostellar candidates; that is, with higher-spatial-resolution imaging studies that can be conducted with very large ground-based telescopes operating in the near-infrared and thermal-infrared spectral regions. For example, the once-planned National New Technology Telescope (NNTf)
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From page 63... ...
It is particularly important to address the key questions related to planetary evolution in studies of such objects. Studies of the immediate post-protostellar collapse phase, when the central regions of the collapsing system are heating up, can be fruitfully conducted at the highest spatial resolutions using the near-infrared and even optical techniques on the largest telescopes.
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From page 64... ...
Radio measurements are ideally suited to providing information on emission mechanisms, electron temperatures and populations, and magnetic field strengths and configurations. Energetic plasma phenomena vary rapidly in time, and so continuous radio monitoring can in principle follow the details of accretion~isk inflow, star spot evolution, jet acceleration, and so on.
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From page 65... ...
SPECTROSCOPIC STUDIES OF EXIRASOLAR-SYSTEM PIANElrS ANI) PREPLANETARY MATERIALS Beyond its use for detection and fundamental characterization by the techniques discussed in Chapter 5, spectroscopy is a potential tool to elucidate physical and chemical environments of planetary and precursor systems.
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From page 66... ...
· Observanona] studies, collection programs and techniques, and laboratory u~vesagahons focused on e~raterrestriz~1 dust should be continued and refined · rhythm this general area of study, He technology of laboratory analysis of small e~raterrestnal samples should be developed to the point that submicron Gains carrying "exoac'' isotopic sig~amres suggestive of presolar origin can be individually identified arid analyze · Final, active encouragement should be given to theoreacal, observational' and laboratory simulation studies of the condensing and chemical nature of dust grams us czrcumstellar environments, of grain interactions with and survival in the interstellar medium arid during infall into accretion disks, and of the chemical and physical properties of icy~rganic grain mantles
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