标题： CARMENES对红矮星周围的系外行星搜索。 重新研究GJ 317、GJ 463和GJ 3512系统以及围绕GJ 9773和GJ 508.2新发现的两颗行星。 显示英文标题

标题： The CARMENES search for exoplanets around M dwarfs. Revisiting the GJ 317, GJ 463, and GJ 3512 systems and two newly discovered planets orbiting GJ 9773 and GJ 508.2

摘要： 对系外行星的调查表明，围绕晚型恒星运行、轨道周期短于1000天的气态巨行星的出现率低于围绕类太阳恒星运行的情况。这与基于核心或尘埃聚集理论的行星形成模型一致。CARMENES系外行星调查一直在对一些显示出长周期趋势或调制的天体进行径向速度观测，这些趋势或调制与在大轨道距离处存在气态巨行星相一致。我们对五个这样的系统进行了分析，这些系统是用CARMENES光谱仪以及IRD光谱仪监测的。此外，我们还使用了存档数据来改进行星系统的轨道参数。我们改进了围绕M型矮星GJ 317、GJ 463和GJ 3512运行的三颗已知行星的参数。我们还确定了行星GJ 3512 c的轨道参数和最小质量，此前对此行星只有下限值。此外，我们还报告了围绕恒星GJ 9733和GJ 508.2发现的两颗新的气态巨行星，但对于第二颗行星只能确定轨道特性的下限。这些新的行星发现增加了已知的在长轨道周期（超过2000天）下围绕金属量低于太阳的M型矮星运行的气态巨行星的少量列表。这些结果表明，气态巨行星似乎更倾向于在宽轨道上形成，而不是在低质量及低金属量恒星的近距轨道上形成。 显示英文摘要

摘要： Surveys for exoplanets indicate that the occurrence rate of gas giant planets orbiting late-type stars in orbits with periods shorter than 1000 days is lower than in the case of Sun-like stars. This is in agreement with planet formation models based on the core or pebble accretion paradigm. The CARMENES exoplanet survey has been conducting radial-velocity observations of several targets that show long-period trends or modulations that are consistent with the presence of giant planets at large orbital separations. We present an analysis of five such systems that were monitored with the CARMENES spectrograph, as well as with the IRD spectrograph. In addition, we used archival data to improve the orbital parameters of the planetary systems. We improve the parameters of three previously known planets orbiting the M dwarfs GJ 317, GJ 463, and GJ 3512. We also determine the orbital parameters and minimum mass of the planet GJ 3512 c, for which only lower limits had been given previously. Furthermore, we present the discovery of two new giant planets orbiting the stars GJ 9733 and GJ 508.2, although for the second one only lower limits to the orbital properties can be determined. The new planet discoveries add to the short list of known giant planets orbiting M-dwarf stars with subsolar metallicity at long orbital periods above 2000 days. These results reveal that giant planets appear to form more frequently in wide orbits than in close-in orbits around low-mass and lower metallicity stars.