Title: Hunting for exoplanets around active stars
Authors: David Stenning - Imperial College London (United Kingdom) [presenting]
David Jones - Texas A&M University (United States)
Eric Ford - Penn State University (United States)
Tom Loredo - Cornell University (United States)
Jessi Cisewski - Yale University (United States)
Robert Wolpert - Duke University (United States)
Abstract: The detection and characterization of exoplanets-planets that orbit stars other than the Sun-is one of the most active areas of research in modern astronomy. Many exoplanets are discovered using the radial velocity technique, which involves detecting the Doppler shift in a stars spectral lines resulting from the gravitational effects of an orbiting planet. A challenge to this approach is that measured radial velocity signals are often corrupted by stellar activity such as spots rotating across the stars surface. A principled method for recovering the underlying planetary radial velocity signal was previously proposed, which uses dependent Gaussian processes to jointly model the corrupted radial velocity signal and proxies for stellar activity. Our approach extends the previous one by (i) incorporating science- and data-driven dimension reduction techniques to extract more informative stellar activity proxies, and (ii) introducing a model comparison procedure to select the best model for the stellar activity proxies at hand from a larger class of models. Our methodology is tested on synthetic data generated by the SOAP 2.0 code, and initial results show substantially improved statistical power for planet detection compared to using existing models from the literature.