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5/3/18: SO/NOAO Joint Colloquium Series: Eric Agol, Univ. Washington


Title: Characterizing the TRAPPIST-1 System

I will describe recent progress on modeling the seven-planet system found to transit a small red dwarf star. A pattern of near-Laplace resonances in the system presaged the period of the seventh planet, subsequently recovered in the K2 dataset. New developments in computational N-body analysis enabled the first estimates of the densities of these temperate, Earth-sized planets with transit timing measurements with Spitzer, K2 and ground-based telescopes. Flux variations of the star indicate the presence of bright spots correlated in time with flares. Future prospects for characterization of the planets may be limited by stellar microvariability, which we are modeling with a novel Gaussian process technique. In spite of the presence of stellar variability, the detection of precise masses, transit transmission spectroscopy, and planet-planet occultations with JWST bodes well.