Shvartzvald Y, Yee J C, Calchi Novati S, Gould A, Lee C-U, Beichman C, Bryden G, Carey S, Gaudi B S, Henderson C B, et al. An Earth-mass Planet in a 1 au Orbit around an Ultracool Dwarf. \apjl. 2017;840 (1) :L3.