Properties of Sun-like Stars with Planets: ρ~1 Cancri, τBootis, and υAndromedae

摘要

Planets have been reported orbiting the Sun-like stars ρ~1 Cnc, τBoo, and υAnd based on low- amplitude radial velocity variations. We have derived information on the first two stars from analysis of spectra, as well as parallel records of high-precision Stromgren b and y photometry and Ca II H + K fluxes. In the case of ρ~1 Cnc, the upper limit (peak to peak) of nondetection of photometric variability at the orbital period is △y ～0.0004 mag. The possibility of a planetary transit cannot be ruled out completely from the photometric data. Variations of the Ca II fluxes suggest a rotational period of ～42 days, in agreement with the inferred v sin i ～2 km s~-1. The age of ρ~1 Cnc is ～5 Gyr, based on its average Ca II flux and a relation between Ca II flux and age.