标题： 由双星演化形成的快速旋转的恒星通常会显得像是单颗恒星。 显示英文标题

标题： Fast rotating stars resulting from binary evolution will often appear to be single

摘要： 快速旋转的恒星很容易在双星系统中产生。双星系统中的吸积星可以通过质量吸积而加速旋转，并迅速接近 breakup 极限。预期两颗恒星之间的合并会形成具有大质量和快速旋转的恒星。这些快速旋转的恒星可能表现为 Be 星或 Oe 星，或者在低金属丰度下，它们可能是长伽马射线暴的前身。考虑到大量恒星存在于紧密双星系统中的高频率，似乎很大比例的快速旋转恒星是由双星相互作用产生的。区分一个作为快速旋转单星诞生的快速旋转恒星和一个由某种双星相互作用产生的快速旋转恒星并不简单。 由于双星相互作用而产生的快速旋转恒星通常看起来像是单星，因为伴星往往是轨道较宽的低质量、低光度恒星。或者，它们在主星超新星爆炸期间合并或双星系统解体后变成了单星。缺乏伴星存在的证据并不能保证该系统在过去没有经历过双星相互作用。 如果双星相互作用是高恒星旋转率的主要原因之一，那么快速旋转恒星中的双星比例预计会较小。这一预测如何依赖于双星相互作用物理过程中的不确定性需要进一步研究。 显示英文摘要

摘要： Rapidly rotating stars are readily produced in binary systems. An accreting star in a binary system can be spun up by mass accretion and quickly approach the break-up limit. Mergers between two stars in a binary are expected to result in massive, fast rotating stars. These rapid rotators may appear as Be or Oe stars or at low metallicity they may be progenitors of long gamma-ray bursts. Given the high frequency of massive stars in close binaries it seems likely that a large fraction of rapidly rotating stars result from binary interaction. It is not straightforward to distinguish a a fast rotator that was born as a rapidly rotating single star from a fast rotator that resulted from some kind of binary interaction. Rapidly rotating stars resulting from binary interaction will often appear to be single because the companion tends to be a low mass, low luminosity star in a wide orbit. Alternatively, they became single stars after a merger or disruption of the binary system during the supernova explosion of the primary. The absence of evidence for a companion does not guarantee that the system did not experience binary interaction in the past. If binary interaction is one of the main causes of high stellar rotation rates, the binary fraction is expected to be smaller among fast rotators. How this prediction depend on uncertainties in the physics of the binary interactions requires further investigation.