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D.M. Williams (Penn State Erie, The Behrend College)
Today ~102 planets are known to orbit 96 sun-like stars, and 86% of the planets are within 50 parsecs of Earth. The stars themselves range in spectral type from F7 to M5, and from luminosity class V (main sequence, like the Sun) to luminosity class III (sub-giants). The companions to most of these stars have been detected through careful long-term monitoring of stellar radial velocity variations, which reveals the product msini (m is mass and i is the inclination of the planet's orbit relative to our line of sight), not the planetary mass m. Thus far, the companions are all more massive than 0.12 MJ (or 2.2 x Neptune) and are located between 0.037 AU and 4.47 AU from their parent stars. Over 40% (42) of the new objects spend at least a portion of their orbits within the liquid-water habitable zone (HZ) of their stars, and many (25) on orbits with eccentricities e > 0.4. Systems with planets whose orbits cross the HZ boundaries might harbor life on terrestrial-like moons if the seasonal temperature extremes resulting from the planets? large orbital eccentricities are not too severe [cf., Williams and Pollard 2002. Inter. J. Astrobio. 1(1), 61-69]. Here we show the locations and range of orbital distances for the known extrasolar planets relative to the HZs around their parent stars.
The author(s) of this abstract have provided an email address for comments about the abstract: dmw145@psu.edu
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Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.