The Pulsars&Clocks project
Linking pulsars and optical clocks
Pulsars are neutron stars in our galaxy that rotate at a very stable frequency, sending out radiowaves that can be detected on Earth as pulses. The arrival time of these pulses is perturbed by various effects, such as processes in the neutron star itself, the orbit of Earth around the sun, and even gravitational waves!
Thus, measuring the arrival times of the pulses very precisely allows us to study all these effects. Time-keeping is currently limited by the performance of the maser used for this purpose, and we investigate ways to improve the maser performance through updates from an optical clock.
In addition, we search for ways in which the extreme long-term stability of pulsars (after all, they have been rotating already for many million years) can utilized to improve the long-term stability of optical clocks, which tend to drift away after some time.