标题： 一颗白矮星双星系统，在轨道周期显示出间歇性无线电脉冲 显示英文标题

标题： A white dwarf binary showing sporadic radio pulses at the orbital period

摘要： 近期的观测揭示了罕见的、之前未知的宇宙射电波闪现，持续时间从毫秒到分钟，并且周期性为几分钟到一小时[1-4]。 这些瞬变的射电信号必定源自银河系内的源，并且源自天体等离子体中的相干发射过程。 它们被认为是在白矮星或中子星周围极端且高度磁化的环境中产生的[5-8]。 然而，这些信号的天体物理起源仍存在争议，可能需要多种前身模型来解释它们多样的特性。 在这里，我们报告了一个瞬变射电源ILJ1101+5521的发现，其大约一分钟长的脉冲以125.5分钟的周期到达。 我们发现ILJ1101+5521是一个M型矮星-白矮星双星系统，其轨道周期与射电脉冲的周期相匹配，当两颗恒星处于合点时可以观察到这些脉冲。 ILJ1101+5521的双星性质表明，一些长周期射电瞬变源于轨道运动调制的观测辐射，而不是孤立旋转的恒星。 我们得出结论，ILJ1101+5521很可能是一个极地系统，在这个系统中，磁相互作用使白矮星的自转和轨道周期同步[9]。 两颗恒星之间的磁相互作用和等离子体交换可能会产生这种间歇性的射电辐射。 这些机制之前已被理论化[10-13]，但尚未通过观测得到证实。 显示英文摘要

摘要： Recent observations have revealed rare, previously unknown flashes of cosmic radio waves lasting from milliseconds to minutes, and with periodicity of minutes to an hour [1-4]. These transient radio signals must originate from sources in the Milky Way, and from coherent emission processes in astrophysical plasma. They are theorised to be produced in the extreme and highly magnetised environments around white dwarfs or neutron stars [5-8]. However, the astrophysical origin of these signals remains contested, and multiple progenitor models may be needed to explain their diverse properties. Here we present the discovery of a transient radio source, ILT J1101+5521, whose roughly minute-long pulses arrive with a periodicity of 125.5 minutes. We find that ILT J1101+5521 is an M dwarf - white dwarf binary system with an orbital period that matches the period of the radio pulses, which are observed when the two stars are in conjunction. The binary nature of ILT J1101+5521 establishes that some long-period radio transients originate from orbital motion modulating the observed emission, as opposed to an isolated rotating star. We conclude that ILT J1101+5521 is likely a polar system where magnetic interaction has synchronised the rotational and orbital periods of the white dwarf [9]. Magnetic interaction and plasma exchange between the two stars may generate the sporadic radio emission. Such mechanisms have been previously theorised [10-13], but not observationally established.