AI 中文总结
本研究发现RCB星WISE J005128.08+645651.7是食双星候选体，其两次3.5年变暗事件或为66年周期的食，若证实将是首颗双星系统RCB星，还通过光谱与大气模型分析了该星的特性。
AI 中文摘要
背景：北冕座R型（RCB）星是缺氢富碳（HdC）超巨星，可能起源于两颗白矮星的并合，因此这类星不应属于密近双星系统，这与当前观测结果一致。目的：本研究验证上述假设，搜索RCB星可能因伴星引发的食现象。方法：利用哈佛照相底片的旧存档测光数据（DASCH），以及Gaia、ASAS-SN、ZTF等现代测光巡天数据搜索食现象，并开展后续光谱观测。结果：发现一颗RCB星WISE J005128.08+645651.7，具有两次持续3.5年的变暗事件，研究认为这些可能是间隔轨道周期66年的食，该星是食双星候选体，下一次食预计在2080年；若得到证实，这将是首颗双星系统中的RCB星，也是已知食双星中第二长的轨道周期，以及持续时间最长的食；光变曲线模拟支持食可能由伴星周围的尘埃盘引发，该星呈现异常大的脉动；后续光谱观测显示其恒星温度约11000K，正常亮度时存在锐发射线（包括禁线），以及极强的星际弥散带；该星可能被更热的色球和延展低密度星云包围，研究计算了其大气模型，模型存在密度反转，推导的化学成分与部分冷极端氦星（EHe）兼容，该星构成了经典RCB星、热RCB星与EHe星之间的桥梁。结论：鼓励未来研究证实或否定该星的双星性质，并搜索其他RCB双星。
英文摘要
Context. R Coronae Borealis (RCB) stars are hydrogen-deficient and carbon-rich (HdC) supergiants that likely originate from a merger of two white dwarfs. As such they are not expected to be members of close binary systems, in agreement with current observations. Aims. We test the above hypothesis and search for eclipses of RCB stars that could be due to a companion. Methods. We exploited old archival photometric data from Harvard photographic plates (DASCH) as well as modern-era photometric surveys such as Gaia, ASAS-SN, and ZTF to search for eclipses, and conducted follow-up spectroscopic observations. Results. We found one RCB star (WISE J005128.08+645651.7) that features two 3.5 yr long dimming events. We argue that these may be eclipses separated by an orbital period of 66 yr and that the star is an eclipsing binary candidate. The next eclipse is predicted for 2080. If confirmed, this would be the first RCB star in a binary system, the second-longest orbital period of any known eclipsing binary, and the longest duration of an eclipse. Light curve simulations support the idea that the eclipses could be caused by a dusty disk around the companion. The star shows unusually large pulsations. Our follow-up spectroscopy indicates a stellar temperature of about 11000 K, the presence of sharp emission lines (including forbidden lines) during the normal brightness, and extremely strong diffuse interstellar bands. The star is likely surrounded by a hotter chromosphere and an extended low-density nebula. We calculated atmosphere models of the star. Models feature a density inversion and the derived chemical composition is compatible with some cool extreme He stars (EHe). The star constitutes a bridge between the classical RCB, hot RCB, and EHe stars. Conclusions. Future research is encouraged to confirm or refute the binary nature of the star and search for other RCB binaries.
Commentsrecently published in A&A
Journal refA&A, 712, A176 (2026)
DOI：10.1051/0004-6361/202557525
