PSR J1718-3719
A pulsar star, PSR J1718-3719 beams high energy radiation out across the universe, typically with clockwork precision. A peculiar characteristic of this pulsar is that occasionally, there is a glitch in the pulse rate.
These glitches are often displayed as a sudden change in the period of the pulsar suddenly drops and then slowly relaxes back to the pre-glitch value at a characteristic rate dependent on the previous value as well as how large the jump was. Behavior like this has been seen in other pulsars including PSR B2334+61 and PSR 1048-5397.
The size of a glitch is measured as a ratio of the change in speed due to the glitch as compared to that of the pre-glitch speed. For past glitches, these have generally been changes that are around a hundredth of a percent. While this may not sound like a large change, the stars on which they act are exceptionally dense neutron stars. As such, even a small change in rotational energy means a large amount of energy involved.
Previously, the largest known glitch was 20.5 x 10-6 for PSR B2334+61. The new glitch in PSR J1718-3718 beats this record with a frequency change of 33.25 x 10-6. Aside from being a record setter, this new glitch does not appear to be following the trend of returning to previous values.
Pulsars tend to have a slow braking applied to them due to a difference between their rotational axes and their magnetic ones. This too generally returns to a standard value for a given pulsar following a glitch, but PSR J1718-3718 defies expectations here as well, having a persistently higher braking effect which has continued to increase.
The effects which may cause these glitches are unknown. There is no evidence to suggest that the phenomenon is something external to the body itself. Instead, astronomers suspect that there are occasional alignments of the stars internal superfluid core which rotates more quickly, with the star's crust that cause the two to occasionally lock together. The phenomenon may have also been caused by a fracturing of the crust of the neutron star or some yet unknown internal reaction.
