AI 中文总结
研究利用苔丝数据和径向速度测量，对π Mensae行星系统进行分析，更新了π Men b、c及提议的π Men d的轨道历表，提高了π Men c周期误差范围精度，估计了π Men d质量范围，还发现π Men c对未来研究有趣且现有数据与第三颗行星存在一致。
AI 中文摘要
系外行星特征描述依赖于对行星轨道和物理参数的精确测量，这对行星动力学和大气演化尤为重要。苔丝发现的第一颗系外行星π Men c是一颗温暖的海王星外行星，围绕一颗明亮的类日恒星运行，该系统中至少还有一颗周期和大小差异很大的行星。π Men c位于1.5 - 2.0地球半径间隙附近，预计已失去原始氢和氦，但保留了较重的化合物如水和二氧化碳。π Men系统通过数十年的径向速度测量得到了很好的观测，苔丝也持续观测了π Men c，获得了六年和21个扇区的光度测量数据。我们对这些苔丝数据和22年的径向速度测量进行了全面分析，以提供π Men b、c和提议的第三颗行星π Men d的更新轨道历表。我们新推导的π Men c周期误差范围比之前的估计提高了一个数量级，并且估计π Men d的质量范围为13.4≤M$_d$<20地球质量。我们发现π Men c是未来用詹姆斯·韦伯太空望远镜进行凌星光谱学研究的一个特别有趣的目标，并且现有的径向速度数据与第三颗行星的存在一致。
英文摘要
Exoplanet characterization relies on precise measurements of planetary orbital and physical parameters. This is particularly important for planetary dynamics and atmospheric evolution, as orbital parameters help constrain system evolution, resolve ambiguities, and gauge atmospheric retention. The first exoplanet discovered by the Transiting Exoplanet Survey Satellite (TESS), $π$ Men c, is a warm sub-Neptune orbiting a bright Sun-like star in a system containing (at least) one other planet with a wildly different period and size. Lying near the 1.5-2.0 $R_{\oplus}$ radius gap, $π$ Men c is expected to have lost its primordial hydrogen and helium, but kept heavier compounds like H$_2$O and CO$_2$. The $π$ Men system is well observed with decades of radial velocity measurements, and TESS has continued to observe $π$ Men c, yielding six years and 21 sectors of photometry. We present a comprehensive analysis of these TESS data and 22 years of radial velocity measurements to provide updated orbital ephemerides for $π$ Men b, c, and the proposed third planet, $π$ Men d. Our newly derived $π$ Men c period error margins are an order of magnitude improved from previous estimates, and we estimate the mass range of $π$ Men d to be 13.4 $\leq$ M$_d$ $<$ 20 M$_{\oplus}$. We find that $π$ Men c is a uniquely interesting target for future transmission spectroscopy studies with JWST, and that existing radial velocity data are consistent with the existence of a third planet.
Comments13 pages, 11 figures, 7 tables. Submitted to AJ with favorable first referee report
