Kepler-296 is a binary star system with two M-dwarf components separated by
0.2 arcsec. Five transiting planets have been confirmed to be associated with
the Kepler-296 system; given the evidence to date, however, the planets could
in principle orbit either star. This ambiguity has made it difficult to
constrain both the orbital and physical properties of the planets. Using both
statistical and analytical arguments, this paper shows that all five planets
are highly likely to orbit the primary star in this system. We performed a
Markov-Chain Monte Carlo simulation using a five transiting planet model,
leaving the stellar density and dilution with uniform priors. Using importance
sampling, we compared the model probabilities under the priors of the planets
orbiting either the brighter or the fainter component of the binary. A model
where the planets orbit the brighter component, Kepler-296A, is strongly
preferred by the data. Combined with our assertion that all five planets orbit
the same star, the two outer planets in the system, Kepler-296 Ae and
Kepler-296 Af, have radii of 1.53 +/- 0.26 and 1.80 +/- 0.31 R_earth,
respectively, and receive incident stellar fluxes of 1.40 +/- 0.23 and 0.62 +/-
0.10 times the incident flux the Earth receives from the Sun. This level of
irradiation places both planets within or close to the circumstellar habitable
zone of their parent star.Comment: Accepted for publication in Ap