Photometric Analysis and Transit Times of TRAPPIST-1 b and c

Abstract

TRAPPIST-1 hosts seven Earth-sized planets transiting an M8 star. We observed mid-transit times of each of the inner two planets with the Astrophysical Research Consortium (ARC) 3.5 m Telescope at Apache Point Observatory (APO) to help constrain the planet masses with transit timing variations, and we outline a procedure for analyzing transit observations of late-M stars with APO. The transit times of TRAPPIST-1 b and c are ${\mathrm{BJD}}_{\mathrm{TDB}}=2457580.87634_{-0.00034}^{+0.00034}$ and $2457558.89477_{-0.00085}^{+0.00080}$, respectively, which will help constrain the planet masses.

1 figure, 2 pages, accepted to RNAAS