Extra-solar planets around HD196050, HD216437 and HD160691

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$\pm$250 d, a semi-amplitude of 38$\pm$4 m s$^{-1}$ and of an eccentricity of 0.33$\pm$0.09. The minimum (M sin $i$) mass of the companion is 2.1$\pm$0.3 M$_{\rm JUP}$ and the semi-major axis is 2.4$\pm$0.5 au. HD 196050 has a period of 1288$\pm$230 d, a semi-amplitude of 54$\pm$8 m s$^{-1}$ and an eccentricity of 0.28$\pm$0.15. The minimum mass of the companion is 3.0$\pm$0.5 M$_{\rm JUP}$ and the semi-major axis is 2.3$\pm$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 midly-eccentric, long-period extra-solar planets around Sun-like stars. As seems to be typical of stars with planets, both stars are metal-rich.