Detection of Two Vela Pulsar 'Glitches'
The initial February 2019 detection of a 'glitch' in the Vela pulsar in HawkRAO observation data is the first by an amateur for any pulsar.
This was followed up about 2.5 years later by the detection of second glitch.
Glitch #1: After 20 months of daily observations, on the 1st February, 2019, the HawkRAO system detected a 'glitch' in the Vela Pulsar.
ATel #12466: Notification of 2019 Vela Glitch on 'Astronomers Telegram'
On the 1st February 2019 at 14:09 (UTC) Vela 'glitched' (refer to ATel #12466 graphic above and original link below).
The glitch (~ 2.5 ppm jump) was clearly seen in HawkRAO data in the MJD 58516 observation as shown by the jump in the spin frequency trace (light blue line) in the archived 'Glitch Monitor Panel' on the right.
This is the first time that a glitch has been recorded and notified by an amateur radio astronomy observatory - in any pulsar.
Glitch #2: A second Vela glitch has been detected in HawkRAO observation data (23rd July, 2021 UTC).
ATel #14808: 2021 Vela Glitch seen in HawkRAO Data on 'Astronomers Telegram'
On the 22rd July 202021 at 15:04 (UTC) Vela 'glitched' again (refer to ATel #14808 image above and original link below).
The glitch (~ 1.25 ppm jump) was clearly seen in HawkRAO data again as shown in the plot below of the offset (in ppm) from the predicted spin frequency.
Notes
The value of the glitch magnitude (ΔF/F = 1.26 ppm) is calculated by doing a linear fit of post-glitch measurements and solving for the epoch of the glitch.
The results published via ATel are as follows...
ATel #14806: 1.26 ppm (no limits specified) - IAR
ATel #14807: 1.26 +/-0.03 ppm - UTMOST
ATel #14808: 1.25+/-0.1 ppm (HawkRAO initial estimate - now updated)
ATel #14812: 1.238+/-0.07 ppm - ORT
Therefore - the latest HawkRAO analysis as shown below is consistent with ATels #14806 and #14807.
The post-glitch 'speedup of slowdown' is clearly shown in the following graph and at 10.2 e-3 is within past glitch values for Vela.The post-glitch plot is done using the pre-glitch value of F1 and so shows that post-glitch the rate of slowdown has increased (i.e., slowing down faster than predicted by the pre-glitch ephemeris). This post-glitch 'speedup of slowdown' is clearly shown in the following graph and at 10.2 e-3 is within past glitch values for Vela.
Observations have continued - but using a different analysis chain based on Ubuntu Mate running on a Raspberry PI 400.