2015ApJ...806....5H

We report detections of new exoplanets from a radial-velocity (RV) survey of metal-rich FGK stars by using three telescopes. By optimizing our RV analysis method to long time-baseline observations, we have succeeded in detecting five new Jovian planets around three metal-rich stars, HD 1605, HD 1666, and HD 67087, with masses of,, and, respectively. A K1 subgiant star, HD 1605 hosts two planetary companions with minimum masses of and in circular orbits with the planets' periods and 2111 days, respectively. HD 1605 shows a significant linear trend in RVs. Such a system consisting of Jovian planets in circular orbits has rarely been found and thus HD 1605 should be an important example of a multi-planetary system that is likely unperturbed by planet-planet interactions. HD 1666 is an F7 main-sequence star that hosts an eccentric and massive planet of in an orbit with AU and eccentricity. Such an eccentric and massive planet can be explained as a result of planet-planet interactions among Jovian planets. While we have found large residuals of, the periodogram analysis does not support any additional periodicities. Finally, HD 67087 hosts two planets of and in orbits with and 2374 days, and and 0.76, respectively. Although the current RVs do not lead to accurate determinations of its orbit and mass, HD 67087 c can be one of the most eccentric planets ever discovered in multiple systems.