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

Three optical telescopes located at the San Pedro Martir National Observatory were used for the first time to obtain multifilter defocused photometry of the transiting extrasolar planets WASP-39b and WASP-43b. We observed WASP-39b with the 2.12 m telescope in the U filter for the first time, and additional observations were carried out in the R and I filters using the 0.84 m telescope. WASP-43b was observed in VRI with the same instrument, and in the i filter with the robotic 1.50 m telescope. We reduced the data using different pipelines and performed aperture photometry with the help of custom routines in order to obtain the light curves. The fit of the light curves (1.5-2.5 mmag rms), and of the period analysis, allowed a revision of the orbital and physical parameters, revealing for WASP-39b a period (4.0552947 ± 9.65 × 10-7 days) which is 3.084 ± 0.774 seconds larger than previously reported. Moreover, we find for WASP-43b a planet/star radius (0.1738 ± 0.0033) which is 0.01637 ± 0.00371 larger in the i filter with respect to previous works, and that should be confirmed with additional observations. Finally, we confirm no evidence of constant period variations in WASP-43b.