Occurrence Rate of Hot Jupiters Around Early-type M Dwarfs Based on Transiting Exoplanet Survey Satellite Data

January 2023 • 2023AJ....165...17G

Authors • Gan, Tianjun • Wang, Sharon X. • Wang, Songhu • Mao, Shude • Huang, Chelsea X. • Collins, Karen A. • Stassun, Keivan G. • Shporer, Avi • Zhu, Wei • Ricker, George R. • Vanderspek, Roland • Latham, David W. • Seager, Sara • Winn, Joshua N. • Jenkins, Jon M. • Barkaoui, Khalid • Belinski, Alexander A. • Ciardi, David R. • Evans, Phil • Girardin, Eric • Maslennikova, Nataliia A. • Mazeh, Tsevi • Panahi, Aviad • Pozuelos, Francisco J. • Radford, Don J. • Schwarz, Richard P. • Twicken, Joseph D. • Wünsche, Anaël • Zucker, Shay

Abstract • We present an estimate of the occurrence rate of hot Jupiters (7 R ≤ R p ≤ 2 R J, 0.8 ≤ P b ≤ 10 days) around early-type M dwarfs based on stars observed by the Transiting Exoplanet Survey Satellite (TESS) during its primary mission. We adopt stellar parameters from the TESS Input Catalog and construct a sample of 60,819 M dwarfs with 10.5 ≤ T mag ≤ 13.5, effective temperatures 2900 ≤ T eff ≤ 4000 K, and stellar masses 0.45 ≤ M * ≤ 0.65 M . We conduct a uninformed transit search using a detection pipeline based on the box least square search and characterize the searching completeness through an injection and recovery experiment. We combine a series of vetting steps including light centroid measurement, odd/even and secondary eclipse analysis, rotation and transit period synchronization tests as well as inspecting the ground-based photometric, spectroscopic, and imaging observations. Finally, we find a total of nine planet candidates, all of which are known TESS objects of interest. We obtain an occurrence rate of 0.27% ± 0.09% for hot Jupiters around early-type M dwarfs that satisfy our selection criteria. Compared with previous studies, the occurrence rate of hot Jupiters around early-type M dwarfs is smaller than all measurements for FGK stars, although they are consistent within 1σ-2σ. There is a trend that the occurrence rate of hot Jupiters has a peak at G dwarfs and falls toward both hotter and cooler stars. Combining results from transit, radial velocity, and microlensing surveys, we find that hot Jupiters around early-type M dwarfs possibly show a steeper decrease in the occurrence rate per logarithmic semimajor axis bin ( ${dN}/d{\mathrm{log}}_{10}a$ ) when compared with FGK stars.


IPAC Authors


David Ciardi

Senior Scientist