AI 中文总结
研究塔比之星不规则光变，分析TESS和径向速度数据发现可能有伴星以至少约1030天周期环绕，拟合排除系外彗星模型，检测到伴星质量和半径，处于巨行星 - 褐矮星区域，未来盖亚DR4将揭示其性质。
AI 中文摘要
KIC 8462852，即塔比之星，在开普勒光变曲线中呈现深度不规则的流量变化，幅度达20%，且无明显周期性。多波长观测显示光度下降与过境尘埃相符，但其起源不明，主要解释是尘埃可能源于系外彗星或小行星碎片家族。TESS数据揭示了与行星或褐矮星相符的独特对称过境事件，支持了行星轨道扰动导致系外来体的理论。对TESS及径向速度数据的分析表明，有一颗伴星可能以至少约1030天的周期环绕塔比之星运行。结合开普勒和其他光度测量的限制，仅五个轨道周期窗口有可能。对前两个窗口的观测显著缩小了允许范围。用系外彗星模型拟合TESS过境效果不佳或需不切实际参数，支持巨大伴星假说。在过境轨道周期检测到质量为$M=9.4^{+4.9}_{-4.1}$ M$_{\mathrm{Jup}}$（3$\sigma$上限<28.0 M$_{\mathrm{Jup}}$），有2.3 $\sigma$置信度，半径$R=1.7\pm0.1$ R$_{\mathrm{Jup}}$，该伴星处于巨行星 - 褐矮星区域，未来盖亚DR4天体测量将揭示其性质。
英文摘要
KIC 8462852, also known as Tabby's star, shows deep, irregular flux variations up to 20 per cent in its Kepler light curve. These unusual events show no apparent periodicity. Multi-wavelength observations show the dips are consistent with transiting dust, although its origin remains uncertain. The leading explanation is that dust may originate from a family of exocomets or planetesimal fragments. TESS data reveal a unique, symmetric transit event consistent with a planet or brown dwarf. This would support the theory that incoming exocometary bodies may result from orbital perturbations by a planet. The analysis of the TESS and, archival and newly obtained radial velocity (RV) data, suggests that a companion could orbit around Tabby's star with a period of at least ~1030 d. When combined with the constraints imposed by Kepler and other photometric surveys, we find only five orbital period windows are possible. We conduct observations to follow-up the first two windows, significantly reducing the allowed ranges. Fitting the TESS transit using exocometary models produces a poor fit or the need of physically unrealistic parameters, favouring the giant companion hypothesis. A 2.3 $σ$ detection of $M=9.4^{+4.9}_{-4.1}$ M$_{\mathrm{Jup}}$ (3$σ$ upper limit < 28.0 M$_{\mathrm{Jup}}$) at the transit orbital period provides tentative evidence of the companion, but more RV observations are required. Along with the radius $R=1.7\pm0.1$ R$_{\mathrm{Jup}}$, the companion would lie in the giant planet-brown dwarf regime. In the future Gaia DR4 astrometry will reveal the nature of this object.
CommentsAccepted for publication to MNRAS. 17 pages, 18 figures
