We present a long-period radio transient (GLEAM-X J0704−37) discovered to have an optical counterpart, consistent with a cool main-sequence star of spectral type M3. The radio periodicity occurs at the longest period yet found, 2.9 hr, and was discovered in archival low-frequency data from the Murchison Widefield Array. High time resolution observations from MeerKAT show that pulsations from the source display complex microstructure and high linear polarisation, suggesting a pulsar-like emission mechanism occurring due to strong, ordered magnetic fields. The timing residuals, measured over more than a decade, show tentative evidence of a ∼6 yr modulation. The high Galactic latitude of the system and the M-dwarf star excludes a magnetar interpretation, suggesting a more likely M-dwarf/white dwarf binary scenario for this system.

中文翻译：

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2.9 小时周期性无线电瞬变，带光纤对应物


我们提出了一个长周期射电瞬变 （GLEAM-X J0704-37），它被发现具有光学对应物，与光谱型 M3 的冷主序星一致。无线电周期发生在迄今为止发现的最长周期 2.9 小时，是在 Murchison 宽场阵列的档案低频数据中发现的。MeerKAT 的高时间分辨率观测表明，来自源的脉动显示出复杂的微观结构和高度线性极化，这表明由于强大的有序磁场而发生了类似脉冲星的发射机制。十多年来测量的时序残差显示了 ∼6 年调制的初步证据。该系统的高银河纬度和 M 矮星排除了磁星解释，这表明该系统更有可能出现 M 矮星/白矮星双星情景。