'Quiet' pulsar suddenly reveals three glitches in 15 years of observations

Astronomers detected three rotational glitches in the pulsar PSR J1637−4642, a young neutron star that had shown no signs of glitches since its discovery. The glitches, observed over 15.5 years of data from the Murriyang radio telescope, included a first glitch that increased its rotation rate by 17.54 microhertz, corresponding to a fractional change of 2.7 parts per million. The second glitch was smaller, changing the rotation rate by 14 nanohertz, and the third was intermediate in strength, producing a frequency increase of 179 nanohertz. The pulsar, which is 41,000 years old, had remained "quiet" for roughly a decade before these glitches occurred. The team, led by Zhaoyi Wang of Xiamen University, analyzed data from February 2009 to October 2024 and found the three glitches. The results suggest that the pulsar's inner crust and superfluid material are in a state of dynamic equilibrium, with the glitches possibly caused by a sudden transfer of angular momentum from the superfluid to the crust. The pulsar's long period of apparent quiescence before the first glitch could indicate a buildup of stress over many years, leading to the internal changes that caused the spin-up event. The findings add to the growing class of young pulsars that exhibit large glitches after extended intervals of apparent quiescence. The study, published in the Astrophysical Journal Letters, highlights the complex timing behavior of young pulsars and the potential role of superfluid material in their rotation dynamics.

AI-generated summary of the original article — see the source for the full story.