Precision radial velocity and photometric monitoring of a large number of stars may reveal hitherto overlooked populations of binary systems consisting of normal stars and unseen compact objects. I will describe our recent efforts to detect such star-compact-object binaries and to interpret their signals. In particular, I will focus on how our modeling of tidal deformation effects on the radial velocity measurements of the red giant star V723 Mon supports a recent claim that the star is orbited by a 3 solar-mass blackhole. I will also present examples of binaries periodically exhibiting microlensing events which we identified from the Kepler data, and discuss their astrophysical implications.

BIO
Kento Masuda is currently an assistant professor in the Department of Earth and Space Science at Osaka University. He obtained his Ph.D. in 2016 from the University of Tokyo, where he primarily worked on characterization of exoplanet system architectures using archival photometric data from the NASA Kepler mission. Then he spent four years in the United States as a NASA Sagan Fellow at Princeton University and as a member of the Institute for Advanced Study, before moving back to Japan in 2020 to join the faculty in the current department. His recent research interests include exoplanets, single and binary stars, and statistical analyses of astronomical datasets.