Characterization of HD 206893 B from Near- to Thermal-infrared

peer reviewedHD 206893 B is a brown-dwarf companion orbiting inside the debris disk of its host star. We detect the brown dwarf in the Ms band using the Keck/NIRC2 instrument and vortex coronagraph. We measure its magnitude to be ${Ms}={12.97}_{-0.11}^{0.10}$ . It is at an angular separation of 0"22 ± 0"03, and a position angle of 39.6° ± 5.4° east of north. Using this Ms-band measurement and the system age, we use three evolutionary models to estimate the mass to be 12-78 M[SUB]Jup[/SUB]. We analyze the atmospheric properties from 1-5 μm using a grid of simulated atmospheric models. We find that a sedimentation flux f[SUB]sed[/SUB] value ~0.2 provides the best fit to the data, suggesting high vertically extended clouds. This may be indicative of high-altitude grains or a circumplanetary disk. Our model radii and luminosities for the companion find the best fits are ages of <100 Myr and masses