Multifilter Transit Observations of WASP-39b and WASP-43b with Three San Pedro Mártir Telescopes

Abstract

Three optical telescopes located at the San Pedro M\\'artir National\nObservatory were used for the first time to obtain multi-filter defocused\nphotometry of the transiting extrasolar planets WASP-39b and WASP-43b. We\nobserved WASP-39b with the 2.12m telescope in the U filter for the first time,\nand additional observations were carried out in the R and I filters using the\n0.84m telescope. WASP-43b was observed in VRI with the same instrument, and in\nthe i filter with the robotic 1.50m telescope. We reduced the data using\ndifferent pipelines and performed aperture photometry with the help of custom\nroutines, in order to obtain the light curves. The fit of the light curves\n(1.5--2.5mmag rms), and of the period analysis, allowed a revision of the\norbital and physical parameters, revealing for WASP-39b a period ($4.0552947\n\\pm 9.65 \\times 10^{-7}$ days) which is $3.084 \\pm 0.774$ seconds larger than\npreviously reported. Moreover, we find for WASP-43b a planet/star radius\n($0.1738 \\pm 0.0033$) which is $0.01637 \\pm 0.00371$ larger in the i filter\nwith respect to previous works, and that should be confirmed with additional\nobservations. Finally, we confirm no evidence of constant period variations in\nWASP-43b.\n