A new long-period radio transient: discovery of pulses repeating every 1.16 h from ASKAP J175534.9−252749.1

This is the authors' abstract. We don't add key points for this paper.

We report the discovery of several new pulses from the source ASKAP J175534.9–252749.1 (J1755–2527), originally identified from a single 2-min long pulse, confirming it as a long-period transient (LPT) with a period of ~ 1.16\, h. The pulses are significantly scattered, consistent with Galactic electron density models. Two of the new pulses also had measurable polarization, but unlike the originally detected pulse, the polarization angle does not behave as expected from the rotating vector model. We interpret historical non-detections of J1755–2527 as an intrinsic intermittency that occurs on month-long time-scales, and discuss possible causes. We conjecture that, like some other LPTs with periods 1\, h, J1755–2527 may host a white dwarf in a binary orbit, but note that its period is marginally shorter than the canonical orbital period minimum of cataclysmic variables. Our work highlights the importance of additional observations in establishing the nature of unusual radio-emitting objects.