AI 中文总结
本研究通过视向速度分析，从DMPP项目中发现三颗恒星，其中DMPP-7拥有0.72倍土星质量行星，HD 67200、HD 2134可能存在类地行星，需进一步观测确认信号起源。
AI 中文摘要
我们对由弥散物质行星项目（Dispersed Matter Planet Project, DMPP）发现的三颗明亮、低活动度恒星进行了视向速度分析。我们采用贝叶斯框架，将纯开普勒模型与通过准周期高斯过程（Gaussian Process, GP）纳入恒星活动的模型进行对比。DMPP-7（HD 118006）是一颗略微演化的恒星，拥有一颗质量为0.72倍土星质量的巨行星（行星质量下限mₚsin i = 69 M⊕），轨道周期P = 4.93天；一个更长的21天至22天周期信号无法明确判定为恒星自转特征还是纯开普勒信号。对于呈现Ca II H&K变异性的HD 67200，仅含GP的模型比纯动力学模型更受青睐；GP模型为一颗轨道周期P = 2.67天的单颗开普勒行星提供了中等强度证据。对于HD 2134，一个21天至32天的自转周期信号与初步的半高全宽（FWHM）变异性相关；含GP的模型未被明确青睐，但所有考量的模型均为一颗额外的轨道周期P = 2.78天的单颗开普勒行星提供了中等强度证据。尽管我们的目标选择倾向于近边侧轨道几何，但在TESS测光中未发现凌星证据。DMPP-7 b处于高半径行星群与海王星脊及草原区域的过渡带。需进一步观测以确定HD 67200和HD 2134的相干短周期信号是恒星起源还是动力学起源；若为行星，其行星质量下限分别为mₚsin i = 2.07 M⊕和mₚsin i = 2.86 M⊕。
英文摘要
We present a radial velocity analysis of three bright, low-activity stars identified by the Dispersed Matter Planet Project (DMPP). We use a Bayesian framework to compare purely Keplerian models with models incorporating stellar activity via a quasi-periodic Gaussian Process (GP). DMPP-7 (HD 118006) is a slightly evolved star that harbours a single 0.72 Saturn-mass giant ($m_\textrm{p}\sin i$ = 69 M$_\oplus$) with an orbital period of P = 4.93 d. A longer 21 d - 22 d period cannot be conclusively confirmed as a stellar rotation signature rather than a purely Keplerian signal. For HD 67200, which exhibits Ca ii H&K variability, a model with only a GP is strongly favoured over a purely dynamical model. The GP model shows moderate evidence for a single Keplerian with P = 2.67 d. For HD 2134, a 21 d - 32 d rotation period signal is associated with tentative FWHM variability. A model with a GP is not conclusively favoured, but all models considered show moderate evidence for an additional single Keplerian with P = 2.78 d. Despite our target selection favouring near edge-on orbital geometries, we find no evidence for transits in TESS photometry. DMPP-7 b lies at the transition between the high-radius population and the Neptunian ridge and savannah regions. Further observations are required to establish whether the coherent short-period HD 67200 and HD 2134 signals are stellar or dynamical in origin. If planetary, the signals correspond to minimum masses of $m_\textrm{p}\sin i$ = 2.07 M$_\oplus$ and $m_\textrm{p}\sin i$ = 2.86 M$_\oplus$
Comments28 pages, 20 Figures
