Updated CHIME/FRB Baseband Localization of FRB 20251229A
ATel #17606; Mason Ng (McGill University, Trottier Space Institute) on behalf of the CHIME/FRB Collaboration
on 16 Jan 2026; 17:23 UT
Credential Certification: Mason Ng (masonng@mit.edu)
Subjects: Radio, Fast Radio Burst
In ATel #17574, we reported the discovery of the potentially hyperactive repeating fast radio burst source, FRB 20251229A. In that ATel, we published best-fit localization coordinates from an initial analysis of the raw voltage (baseband) data using an older version of the localization pipeline (Michilli et al. 2021). Here, we update the best-fit baseband localization for FRB 20251229A using a newer version of the pipeline, with the latest calibration methods. The new localization, which is approximately 35" away from the previously reported localization (ATel #17574), is the following with errors quoted at 1σ uncertainty:
RA (J2000): 20h 41m 23.9s +/- 1.8s
Dec. (J2000): 16° 01' 31" +/- 36"
RA (J2000): 310.3494 +/- 0.0077 deg.
Dec. (J2000): 16.0252 +/- 0.0099 deg.
