Uniform age analysis of transiting brown dwarf host stars

This work explores the discrepancies between the transiting brown dwarf (BD) population and substellar age-radius relationships by 1) performing a homogeneous analysis of the ages of BD host stars with the MIST models, and 2) examining radius inflation mechanisms in BDs and giant planets and comparing the effects of these as a function of mass. For the first time, this work allows us to be able to compare the relative ages of transiting BD host stars for all 47 known transiting BDs (as of March 2024). This work also takes a more critical look at the potential causes of radius inflation in transiting BDs as a function of mass. Both low-mass (13-25 Jupiter masses) and high-mass (70-75 Jupiter masses) brown dwarfs show clear signs of radius inflation at ages beyond 1 Gyr, but it is unclear whether or not the inflation mechanisms are shared between low- and high-mass brown dwarfs. This study shows that for most BDs above 25 Jupiter masses, incident flux may be negligible as a primary factor in radius inflation, which highlights the mass dependence of this phenomenon and distinguishes it from incident flux radius inflation seen in the giant planet population.