A 154-millisecond rotation period is a spin frequency of about 6.49 hertz [1][1]. Divide the 2018 jump of 17.54 microhertz into that and the fractional step is 2.70 parts per million, which is what the paper reports [5][2]. Run the same division on the smallest of the three events, 14 nanohertz, and the step is about 2.2 parts per billion [6][4]. The largest event is roughly 1,250 times the smallest, and the same star produced both inside seven years [3]. Whether the small ones appear in anyone's catalogue is a question about timing precision and cadence rather than about the neutron star.
Where the events sit in time matters as much as their sizes. The archive opens in February 2009 and the first glitch lands around 2018, so about nine years, roughly 58 percent of the record, passed with nothing [2][5][6]. The third falls near late 2023 or 2024, close to the end of the span [7]. Had Parkes stopped timing this pulsar in 2017, "quiet" would still have been the accurate description [8].
Wang and colleagues put two readings on that silence, and they are not the same claim. They write that the pulsar "adds to the growing class of young pulsars that exhibit large glitches after extended intervals of apparent quiescence," and conclude that "even 'quiet' pulsars can harbor significant glitch activity" [13][14]. They also suggest the long silence could reflect stress accumulating inside the star for many years before the spin-up [15]. The first reading makes quiet a fact about the observing log. The second makes it a physical stage with an internal clock, in which case the label is informative rather than an artifact. Three glitches in one star cannot separate the two, and this work does not count how many quiet young pulsars have been re-timed over comparable baselines, so the growing class is a characterisation and not a measured rate.
The 1.9 percent figure needs the same care. It comes from modelling how the pulsar relaxed after the 2018 glitch, which it did over a timescale near 102 days rather than settling at once, and the number is the share of the star's moment of inertia that the model assigns to superfluid in the inner crust [9][10]. That is a fit. It carries the model's assumptions and however densely the months-long recovery was sampled. The cause of glitches is still not established; the working picture is angular momentum handed abruptly from the interior superfluid to the solid crust, and these data sit comfortably with it [12]. Comfortable is weaker than confirmed, and the paper does not claim more.
For population work, the useful thing to keep beside a label like "no glitches" is the number of years behind it. Nine years of Parkes data supported that label for PSR J1637-4642; extending the same telescope's record to 15.5 years replaced it with three events [2][4][8].
