tau Boo b: Not so bright, but just as heavy
  We present new results derived from high-resolution optical spectra of the tau Boo system, secured in March-May 2000. The results do not show the same feature reported by Cameron et al (1999) as a candidate reflected-light signature from the planet. Together with earlier results from the 1998 and 1999 seasons, the new data yield a 99.9 percent upper limit on the opposition planet/star flux ratio epsilon<3.5E-5 between 387.4 and 586.3 nm, a factor 3 deeper than the upper limit of Charbonneau et al (1999). For an assumed planet radius Rp= 1.2 RJup, the upper limit on the mean geometric albedo is p < 0.22, 40 percent that of Jupiter. We find new evidence that the star's rotation is synchronised with the planet's orbital motion. Using a Monte Carlo analysis we infer that the planet's mass must lie in the range 5.5 to 10 times the mass of Jupiter. 
Andrew Collier Cameron, Keith Horne, David James (University of St   Andrews), Alan Penny (Rutherford Appleton Laboratory), ...