AI 中文总结
该研究发现了21秒差距处近邻K型矮星HD 38230的白矮星伴星，通过多观测数据确定其轨道与质量，该系统是迄今第11近的类天狼星系统，反映本地白矮星普查存在不完备性。
AI 中文摘要
白矮星是太阳附近区域中最稀有、最暗弱的恒星之一，因此始终难以探测。尽管盖亚（Gaia）任务极大拓展了人类对孤立白矮星的认知，但有限的对比度灵敏度使得亮度高得多的太阳型恒星的白矮星伴星很容易被遗漏，留下了一组仅能通过高对比度成像发现的“类天狼星系统”中的白矮星。本文报告了近邻K0V型恒星HD 38230（HIP 27207）的一颗白矮星伴星的发现：该伴星HD 38230 B最初作为TRENDS高对比度成像巡天的一部分，通过凯克（Keck）/NIRC2观测被探测到，未获得天体测量解的情况下被盖亚（Gaia）探测到，还被文献中的利克（Lick）/ShaneAO和帕洛玛（Palomar）/PHARO独立观测到。结合跨越6年的多次成像探测，本文证实HD 38230 B是受引力束缚的伴星，其测光结果仅与白矮星相符。通过结合相对天体测量、25年以上的高精度视向速度观测以及依巴谷-盖亚（Hipparcos-Gaia）天体测量对双星轨道的分析，尽管观测跨度较短，仍对周期P=1390⁺³¹⁰₋₂₀₀年的轨道施加了严格约束，并给出了该白矮星的精确动力学质量M_B=0.71⁺⁰.⁰⁶₋₀.₀₅M⊙。该系统距离为21秒差距，是迄今已知的第11近的类天狼星系统，凸显了本地白矮星普查仍存在不完备性。
英文摘要
White dwarfs are among the rarest and faintest stars found in the solar neighbourhood and are therefore persistently challenging to detect. Whereas the \textit{Gaia} mission has vastly expanded our knowledge of isolated white dwarfs, limited contrast sensitivity means that white dwarfs companions to much brighter solar-type stars are easily missed, leaving a subset of white dwarfs in "Sirius-like systems" that can only be discovered via high-contrast imaging. Here we report the discovery of a white dwarf companion to the nearby K0V star HD 38230 (HIP 27207). The companion, HD 38230 B, was originally detected with Keck/NIRC2 observations taken as part of the TRENDS high-contrast imaging survey, was detected by \textit{Gaia} without an astrometric solution, and was independently observed using Lick/ShaneAO and Palomar/PHARO in the literature. Combining these multiple imaging detections spanning 6 years, we demonstrate that HD 38230 B is a gravitationally bound companion and has photometry consistent only with a white dwarf. Our analysis of the binary orbit, combining relative astrometry with over 25 years of precise radial velocity observations and \textit{Hipparcos-Gaia} astrometry, results in strong constraints on the $P$ = $1390^{+310}_{-200}$ year orbit despite the short observational span, and provides a precise dynamical mass of $M_B$ = $0.71^{+0.06}_{-0.05}$ $M_\odot$ for the white dwarf. At 21 pc, this is the 11th-nearest Sirius-like system known to date, highlighting residual incompleteness in the local white dwarf census.
Comments18 pages, 6 figures, 4 tables. Submitted to AAS Journals. Comments welcome!
