High-precision photometry by telescope defocussing – VI. WASP-24, WASP-25 and WASP-26★

Abstract

We present time-series photometric observations of thirteen transits in the\nplanetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital\nobliquity measurements, WASP-24 and WASP-26 have been observed with Spitzer,\nand WASP-25 was previously comparatively neglected. Our light curves were\nobtained using the telescope-defocussing method and have scatters of 0.5 to 1.2\nmmag relative to their best-fitting geometric models. We used these data to\nmeasure the physical properties and orbital ephemerides of the systems to high\nprecision, finding that our improved measurements are in good agreement with\nprevious studies. High-resolution Lucky Imaging observations of all three\ntargets show no evidence for faint stars close enough to contaminate our\nphotometry. We confirm the eclipsing nature of the star closest to WASP-24 and\npresent the detection of a detached eclipsing binary within 4.25 arcmin of\nWASP-26.\n