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R. S. Simon (NRAO), S. S. Vogt (UCO/Lick Observatory)
There is broad interest in the problem of identifying and characterizing terrestrial (Earth-like) planets outside of our Solar System. Several studies are underway to develop concepts and plans for the Terrestrial Planet Finder (TPF) space mission (see Beichman et al., 1999: "Terrestrial Planet Finder"). TPF, like other missions in the early planning stages, aims to search selected nearby stars for the existence of terrestrial planets, and characterize any planets that may be discovered through low-resolution spectroscopy and other measurements. The high contrast ratio between a star and any nearby planet, the small angular scale required, and the possibility of dust emission masking the planet's signature, combine to make the overall TPF problem challenging.
A vital aspect of instrument and mission design for TPF is selecting appropriate target stars. We report here on the characteristics of a carefully defined complete sample of nearby stars suitable for terrestrial planet searches. Beginning with the more than 7,000 known stars located within 50 parsecs of the Sun, we have applied a number of selection criteria to identify a complete sample of about 160 promising target stars for TPF. Our selection criteria aim towards the ability to detect Earth-like planets: those planets with equilibrium temperature and size similar to Earth. The resulting target list places significant requirements on TPF, if TPF is to search a statistically interesting sample of stars.
An important result is that most stars of interest for TPF will be harder to search for Earth-like planets than an analogue to the Solar System observed from 10 parsecs distance. The typical system in our final sample is smaller, and further away than such a Solar System analogue.
The author(s) of this abstract have provided an email address for comments about the abstract: rsimon@nrao.edu