K‐band transit and secondary eclipse photometry of exoplanet OGLE‐TR‐113b

We present high-precision K-band photometry of the transit and secondary eclipse of extra-solar planet OGLE-TR-113, using the SOFI near-infrared instrument on European Southern Observatory's New Technology Telescope. Data were taken in 5-s exposures over two periods of 3-A h, using random jitter position offsets. In this way, a relative photometric precision of ∼1 per cent per frame was achieved, avoiding systematic effects that seem to become dominant at precisions exceeding this level, and resulting in an overall accuracy of 0.1 per cent per ∼10 min. The observations of the transit show a flat-bottomed light-curve indicative of a significantly lower stellar limb darkening at near-infrared than at optical wavelengths. The observations of the secondary eclipse result in a 3σ detection of emission from the exoplanet at 0.17 ± 0.05 per cent. However, residual systematic errors make this detection rather tentative.