该研究团队使用紫外光度法来识别潜在的剥离氦星，并对其中的25颗进行了光谱学研究。他们发现这些恒星具有高温（约6万到10万开尔文）、高表面引力和表面氢耗尽的特点。其中16颗恒星还表现出双星运动。这些性质与初始质量为8到25 M☉的恒星相符，这些恒星可能被双星相互作用剥离。它们的质量介于亚矮星氦星和沃尔夫-拉叶星之间。研究人员提出，这些恒星可能是剥离包层超新星的祖先。
据悉，大质量恒星富含氢的外层可以通过与双星伴星的相互作用而被移除。理论模型预测这种剥离会产生2到8太阳质量(M☉)的热氦恒星，然而，到目前为止，只有一个这样的系统被确定。
附：英文原文
Title: An observed population of intermediate-mass helium stars that have been stripped in binaries
Author: M. R. Drout, Y. Gotberg, B. A. Ludwig, J. H. Groh, S. E. de Mink, A. J. G. O’Grady, N. Smith
Issue&Volume: 2023-12-15
Abstract: The hydrogen-rich outer layers of massive stars can be removed by interactions with a binary companion. Theoretical models predict that this stripping produces a population of hot helium stars of ~2 to 8 solar masses (M☉), however, only one such system has been identified thus far. We used ultraviolet photometry to identify potential stripped helium stars then investigated 25 of them using optical spectroscopy. We identified stars with high temperatures (~60,000 to 100,000 kelvin), high surface gravities, and hydrogen-depleted surfaces; 16 stars also showed binary motion. These properties match expectations for stars with initial masses of 8 to 25 M☉ that were stripped by binary interaction. Their masses fall in the gap between subdwarf helium stars and Wolf-Rayet stars. We propose that these stars could be progenitors of stripped-envelope supernovae.
DOI: ade4970
Source: https://www.science.org/doi/10.1126/science.ade4970