Pulsar Timing

Detecting exoplanets by measuring variations in the precisely timed radio pulses from a pulsar.

Pulsars are rapidly spinning neutron stars that emit radio pulses with extraordinary precision,essentially cosmic clocks. If a planet orbits a pulsar, the gravitational pull causes tiny variations in the arrival times of these pulses. By analyzing these timing residuals, astronomers can determine the planet's mass and orbit. This method led to the very first confirmed exoplanet discovery in 1992, when Alex Wolszczan and Dale Frail found two planets orbiting the pulsar PSR B1257+12. Pulsar planets are extremely rare and exist in harsh radiation environments very different from our solar system.