Fourteen new companions from the Keck and Lick radial velocity survey including five brown dwarf candidates
2007
ASTROPHYSICAL JOURNAL
We present radial velocities for 14 stars on the California and Carnegie Planet Search target list that reveal new companions. One star, HD 167665, was fit with a definitive Keplerian orbit leading to a minimum mass for the companion of 50.3 M-Jup at a separation from its host of similar to 5.5 AU. Incomplete or limited phase coverage for the remaining 13 stars prevents us from assigning to them unique orbital parameters. Instead, we fit their radial velocities with Keplerian orbits across a grid of fixed values for M sin i and period P, and use the resulting chi(2)(v) surface to place constraints on M sin i, P, and semimajor axis a. This technique allowed us to restrict M sin i below the brown dwarf- stellar mass boundary for an additional four companions ( HD 150554, HD 8765, HD 72780, HD 74014). If the combined five companions are confirmed as brown dwarfs, these results would comprise the first major catch of such objects from our survey beyond similar to 3 AU.