CHIME/FRB/Pulsar Detection of Renewed Activity from J1634+44
ATel #17434; Kaitlyn Shin (Caltech) for the CHIME/FRB/Pulsar Collaborations
on 5 Oct 2025; 04:09 UT
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Credential Certification: Kaitlyn Shin (kshin@mit.edu)
The CHIME/FRB and CHIME/Pulsar collaborations report the reactivation of the long-period radio transient J1634+44 (Dong et al. 2025, ApJ, 988L, 29; Bloot et al. 2025, A&A, 699, A341). Bursts were detected on 2025 September 29 MJD 60947.99247; on 2025 October 1 MJD 60949.98855; and on 2025 October 3 MJD 60951.98459490741. These are topocentric TOAs measured from the CHIME/FRB real-time system and the CHIPSPIPE pipeline (Dong et al. 2023, MNRAS, 4, 5132), and are referenced to a frequency of 400.1953125 MHz using a dispersion measure of ~25 pc/cm3. These TOAs are preliminary estimates; refined TOAs suitable for timing analyses will be presented elsewhere. The bursts arrive in phase with those presented in Dong et al. 2025, ApJ, 988L, 29.
This "every other day" detection cadence is in line with typical behavior of CHIME/FRB observations during previous sustained active periods of J1634+44. VLA ToO observations have been triggered (PI: Dong, VLA/25B-233); the commensal VLA/realfast system detected multiple bursts on both 2025 October 3 and 2025 October 4 UTC, showing J1634+44 is also currently active at L-band frequencies.
Additional observations are strongly encouraged at all wavelengths.
Dynamic spectrum of J1634+44
