In recent years, radial velocity (RV) surveys have widened our knowledge of planet occurrence rate among sun-like stars and cooler dwarf stars. Next-generation spectrographs are providing new extreme-precision RVs, pushing towards the 10 cm/s limit needed to find Earth-like exoplanets. At this level of RV precision we encounter new challenges in our hunt for planets: stellar activity and spurious peridogram peaks due to statistical randomness. Surface rotation, starspots, oscillations, and granulation are all types of stellar activity that can mimic or mask real planet signals. Additionally, unevenly spaced observations cause spectral window artifacts in the Lomb-Scargle periodogram that can also be misinterpreted as real signals. In this talk I will give an overview of frequency domain methods developed to identify and disentangle stellar activity and spurious periodogram peaks from planet detections. I will discuss Welch's power spectrum as an alternative to the Lomb-Scargle periodogram that helps mitigate the frequency domain noise. We can also compute the magnitude squared coherence between simultaneously measured activity indicators and RVs to detect shared activity signals. By suppressing the false positive rate in RV surveys, we can ensure that next-generation direct imaging missions such as NASA's Habitable World Observatory have high-quality target lists.

For Zoom connection information, please contact Emanuele Paolo Farina (emanuele.farina_at_noirlab.edu).

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