Corrected photometry for GJ 1132 for all eclipses

We collected 21 transit observations of GJ 1132b with the MEarth-South array. We obtained 100 near-continuous hours of observations with the Spitzer Space Telescope, including two transits of GJ 1132b and spanning 60% of the orbital phase of the maximum (6.9-day) period at which bodies coplanar with GJ 1132b would transit.

We exclude transits of additional Mars-sized bodies, such as a second planet or a moon, with a confidence of 99.7%. We find that the planet-to-star radius ratio inferred from the MEarth and Spitzer light curves are discrepant at the 3.7{sigma} level, which we ascribe to the effects of starspots and faculae. When we combine the mass estimate of the star (obtained from its parallax and apparent K_s_ band magnitude) with the stellar density inferred from our high-cadence Spitzer light curve (assuming zero eccentricity), we measure the stellar radius of GJ 1132 to be 0.2105_-0.0085_^+0.0102^ R_{sun}_, and we refine the radius measurement of GJ 1132b to 1.130+/-0.056 R_{Earth}_.