Drift Rates of Narrowband Signals in Long-term SETI Observations for Exoplanets

The Doppler shift of a radio signal is caused by the relative motion between transmitter and receiver. change in frequency over time called drift rate. In studies SETI (Search for Extraterrestrial Intelligence), extraterrestrial narrowband signals are expected to appear "chirped" since both exoplanet Earth moving. Such planet rotation orbital revolution around central star can cause non-zero Other motions receiver, such as gravitational redshift galactic potential, negligible. this paper, we mainly consider common cases that rate contributed rotations orbits celestial mechanics perspective, briefly discuss other different from Earth-exoplanet one. We obtain pseudosinusoidal drifting result with long-term observations, shorter periods exoplanets. Exoplanets higher eccentricities asymmetric drifting. should be intermittent curves observations. characteristics pseudo-sinusoidal curves, another new criterion signals, applied reobservations future research.