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تسجيل مستخدم جديدTwo intermediate-mass transiting brown dwarfs from the TESS mission
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We report the discovery of two intermediate-mass brown dwarfs (BDs), TOI-569b and TOI-1406b, from NASAs Transiting Exoplanet Survey Satellite mission. TOI-569b has an orbital period of $P = 6.55604 pm 0.00016$ days, a mass of $M_b = 64.1 pm 1.9 M_J$, and a radius of $R_b = 0.75 pm 0.02 R_J$. Its host star, TOI-569, has a mass of $M_star = 1.21 pm 0.03 M_odot$, a radius of $R_star = 1.47 pm 0.03 R_odot$, $rm [Fe/H] = +0.29 pm 0.09$ dex, and an effective temperature of $T_{rm eff} = 5768 pm 110K$. TOI-1406b has an orbital period of $P = 10.57415 pm 0.00063$ days, a mass of $M_b =46.0 pm 2.7 M_J$, and a radius of $R_b = 0.86 pm 0.03 R_J$. The host star for this BD has a mass of $M_star =1 .18 pm 0.09 M_odot$, a radius of $R_star = 1.35 pm 0.03 R_odot$, $ rm [Fe/H] = -0.08 pm 0.09$ dex and an effective temperature of $T_{rm eff} = 6290 pm 100K$. Both BDs are in circular orbits around their host stars and are older than 3 Gyr based on stellar isochrone models of the stars. TOI-569 is one of two slightly evolved stars known to host a transiting BD (the other being KOI-415). TOI-1406b is one of three known transiting BDs to occupy the mass range of $40-50 M_J$ and one of two to have a circular orbit at a period near 10 days (with the first being KOI-205b).Both BDs have reliable ages from stellar isochrones in addition to their well-constrained masses and radii, making them particularly valuable as tests for substellar isochrones in the BD mass-radius diagram.
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