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W.~D. Cochran, A.~P. Hatzes (U.~Texas)
Now that Jovian-mass extrasolar planets are being discovered using high-precision radial velocity techniques, it is important to focus large survey programs on important questions relating to the origin and evolution of extrasolar planetary systems. We are particularly interested in how the characteristics of the planetary system depend on the mass of the central star. Do massive stars form massive planets, or does tidal truncation limit the size to which a planet can grow? What role does early dynamical evolution play in systems with various mass stars? Do low mass stars form fewer planets, or perhaps lower mass planets? The Hyades star cluster is an excellent place to seek answers to these questions. The Hyades is one of the nearest star clusters to the Sun, and represents a sample of stars formed at the same epoch with a uniform heavy element abundance. We are using the Keck~1 telescope with its HIRES spectrograph to conduct a high-precision radial velocity survey of late-F through mid-M Hyades dwarfs, in order to answer these questions. In this carefully selected sample, the dominant independent variable is the mass of the star. We are now in our fourth season of observing. We present results on a wide variety of stars of various masses, including some stars showing variations possibly indicative of Jovian-mass companions.
This work is funded by NASA Grant NAG5-4384.
The author(s) of this abstract have provided an email address for comments about the abstract: wdc@astro.as.utexas.edu