Direct Test of Brown Dwarf Model Predictions Through Secondary Eclipse Spectroscopy of LHS 6343 C

William Frost ( Université de Montréal )

Brown dwarf (BD) observations are usually reliant on atmospheric and evolutionary models to output a sufficient set of physical parameters (i.e. mass, radius, luminosity, temperature, age). This is because most observed BDs are isolated field objects, meaning only photometric observations are possible. Unlike most main sequence stars, there does not exist an extensive, empirically calibrated relationship between physical parameters for BDs. In fact, they are degenerate in certain regimes (e.g. mass and age), and these degeneracies are impossible to resolve using only photometric observations.

Fortunately, BD models are succesful in reproducing observational photometry and spectra for field objects. However, these models still lack an empirical calibration, meaning the underlying physical parameters they predict are not verified against direct measurements from observations. Such measurements are possible with BD eclipsing binary systems, where radial velocity, transit and eclipse techniques can be applied. A sufficient collection of such systems can become the foundation for an empirical calibration of BD parameters.

One of the most promising systems is LHS 6343, where a BD (member C) orbits the primary member (A) of an M-dwarf binary. Existing research has directly measured the BD's mass and radius. This talk will go over my master's project to obtain the remaining measurables (temperature, luminosity) and compare this suite of directly obtained physical parameters to what BD models predict given the emission spectrum of LHS 6343 C.