AI 中文总结
研究对七颗及另外三颗疑似戴森球候选体的M型矮星进行光度和光谱数据分析，通过校准的经验关系推导恒星参数，虽未明确红外过剩原因，但指出JWST和ALMA观测或能探测相关情况，还发现两颗恒星与红背景星系叠加。
AI 中文摘要
拥有戴森球的恒星的红外通量过剩代表了地外智慧的一种潜在技术特征。在之前的赫菲斯托斯计划论文中，我们强调了300秒差距内七颗具有异常红外特性的M型矮星，其特性似乎类似于戴森球预期的特性。在本研究中，我们对这七个天体以及另外三个具有类似特性的天体的光度数据以及部分光谱数据进行了分析，以进一步确定它们的性质。从校准后的M型矮星经验关系推导出的恒星参数显示，与主序星的总体M型矮星群体相比没有异常。虽然我们目标的红外特性类似于处于过渡状态的星周盘，但有光谱数据的天体没有显示出通常与此类天体相关的年轻迹象。我们的一个光谱目标确实显示出微弱的Hα发射，但这更可能归因于恒星活动而非年轻恒星预期的气态吸积盘。经过分析，我们仍然没有找到这些恒星红外过剩的明确解释，但指出用詹姆斯·韦布空间望远镜（JWST）和/或阿塔卡马大型毫米波/亚毫米波阵列（ALMA）进行观测将能够探测红外过剩是由于星周尘埃发射或在较短波长未被探测到的红外亮背景源的情况。对于我们的两颗恒星，JWST观测最近揭示了与非常红的背景星系的叠加。
英文摘要
The infrared-flux excess of stars harbouring Dyson spheres represent one potential technosignature of extraterrestrial intelligence. In a previous Project Hephaistos paper, we highlighted seven M dwarfs within 300 pc with unusual infrared properties that seem to resemble those expected for Dyson spheres. In the present study, we present an analysis of photometric and, in some cases, spectroscopic data on these seven objects, plus three additional objects with similar properties, to further constrain their nature. The stellar parameters, derived from calibrated empirical relationships for M dwarfs, reveal no irregularities with respect to the overall M-dwarf population of main-sequence stars. While the infrared properties of our targets resemble those of circumstellar disks in a transitional state, the objects with spectroscopic data show no signs of youth usually associated with such objects. One of our spectroscopic targets does exhibit weak H$α$ emission, but this is more likely attributed to stellar activity than to the gaseous accretion disk expected for a young star. After this analysis, we still find no clear explanation for the infrared excess of these stars, but note that observations with the JWST and/or the Atacama Large Millimeter/submillimeter Array would be able to probe scenarios in which the infrared excess is due to circumstellar dust emission or an infrared-bright background source that remains undetected at shorter wavelengths. For two of our stars, JWST observations have recently revealed superpositions with very red background galaxies.
Comments11 pages, 9 figures
