Weather on brown dwarfs
Variability is common in brown dwarfs. As they rotate, any inhomogeneous atmospheric structure can cause variability in their light curves. Some Young L- and T- type brown dwarfs have similar masses, temperatures and ages as direct-imaged exoplanets. These free-floating planetary-mass objects are exoplanets analogues and are easier to observe than exoplanets because they are not obscured by close bright stars. Studying their variability not only helps us understand atmospheric structures of young L and T dwarfs which are believed experiencing drastic cloud formation and condensation but also can be used to infer giant exoplanet atmospheres.
TRAP for vAPP
TRAP is a temporal systematics model for direct detection of exoplanets (Samland et al.2021). The vector Apodizing Phase Plate (vAPP) is a pupil-plane coronagraph that uses liquid crystals and direct writing techniques (Snik et al.2012; Otten et al.2014). Depending on the design, it can produce a dark hole with a certain shape in its point spread function (PSF), where is easier to search for exoplanets. We apply the TRAP algorithm to two types of vAPP datasets, gvAPP180 which produces two PSFs with two 180-degree dark holes and dgvAPP360 which produces one PSF with a 360-degree dark hole.