SPEARNET normalized photometry of HAT-P-26

We present a new set of 13 transit light curves from optical ground-based observations and combine them with light curves from the Wide Field Camera 3 on the Hubble Space Telescope, the Transiting Exoplanet Survey Satellite, and previously published ground-based data. We refine the planetary parameters of HAT-P-26 b and undertake a TTV analysis using 33 transits obtained over seven years.

The TTV analysis shows an amplitude signal of 1.98{+/-}0.05minutes, which could result from the presence of an additional ~0.02MJup planet at a 1:2 mean-motion resonance orbit. Using a combination of transit depths spanning optical to near-infrared wavelengths, we find that the atmosphere of HAT-P-26b contains 2.4_-1.6}^+2.9^% H2O with a derived temperature of 590_-50_^+60^K.