Extrasolar planets around HD 196050, HD 216437 and HD 160691

Abstract

We report precise Doppler measurements of the stars HD 216437, HD 196050 and HD 160691 obtained with the Anglo-Australian Telescope using the UCLES spectrometer together with an iodine cell as part of the Anglo-Australian Planet Search. Our measurements reveal periodic Keplerian velocity variations that we interpret as evidence for planets in orbit around these solar type stars. HD 216437 has a period of 1294 ± 250 d, a semi-amplitude of 38 ± 3 m s-1 and an eccentricity of 0.33 ± 0.09. The minimum (M sin i) mass of the companion is 2.1 ± 0.3 MJUP and the semi-major axis is 2.4 ± 0.5 au. HD 196050 has a period of 1300 ± 230 d, a semi-amplitude of 49 ± 8 m s-1 and an eccentricity of 0.19 ± 0.09. The minimum mass of the companion is 2.8 ± 0.5 MJUP and the semi-major axis is 2.4 ± 0.5 au. We also report further observations of the metal-rich planet bearing star HD 160691. Our new solution confirms the previously reported planet and shows a trend indicating a second, longer-period companion. These discoveries add to the growing numbers of mildly eccentric, long-period extrasolar planets around metal-rich Sun-like stars.