We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V?=?12.0) solar-type star (Teff = 6000 ± 100?K, [Fe/H] = –0.05 ± 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14?days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533?days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M p = 0.56 ± 0.02M Jup and a radius R p = 1.12 ± 0.04R Jup. In addition, there is a linear trend of 40?m?s–1?yr–1 in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet.
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机译：我们报告发现了一颗绕着TYC 6446-326-1恒星运行的行星的发现。 WASP-22恒星是中等亮度（V？=？12.0）太阳型恒星（Teff = 6000±100？K，[Fe / H] = –0.05±0.08）。用WASP-South仪器获得的恒星的光曲线显示出周期性的类似过渡的特征，深度约为1％，持续时间为0.14天。使用Faulkes Telescope South获得的z波段光度法可以确定光曲线中是否存在类似过渡的特征。用CORALIE和HARPS光谱仪获得的高分辨率光谱图证实了在近圆形轨道上存在一个行星质量伴星，其轨道周期为3.533天。通过对光谱和光度数据的组合分析，假设该恒星是典型的主序恒星，我们估计该行星的质量M p = 0.56±0.02M Jup，半径R p = 1.12±0.04R Jup。此外，在16个月内测得的径向速度线性趋势为40？m？s-1？yr-1，由此我们可以推断出该系统中存在长周期轨道的第三物体。伴星可能是低质量的M矮星，白矮星或第二行星。
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