Tregloan-Reed, J.J.Tregloan-ReedSouthworth, J.J.SouthworthMancini, L.L.ManciniMollière, P.P.MollièreCiceri, S.S.CiceriBruni, I.I.BruniRICCI, DAVIDEDAVIDERICCIAyala-Loera, C.C.Ayala-LoeraHenning, T.T.Henning2020-10-232020-10-2320180035-8711http://hdl.handle.net/20.500.12386/27940We present high-precision photometry of eight separate transit events in the HAT-P-32 planetary system. One transit event was observed simultaneously by two telescopes of which one obtained a simultaneous multiband light curve in three optical bands, giving a total of 11 transit light curves. Due to the filter selection and in conjunction with using the defocused photometry technique, we were able to obtain an extremely high-precision, ground-based transit in the u band (350 nm), with an rms scatter of ≈1 mmag. All 11 transits were modelled using PRISM and GEMC, and the physical properties of the system calculated. We find the mass and radius of the host star to be 1.182 ± 0.041 M<SUB>☉</SUB> and 1.225 ± 0.015 R<SUB>☉</SUB>, respectively. For the planet, we find a mass of 0.80 ± 0.14 M<SUB>Jup</SUB>, a radius of 1.807 ± 0.022 R<SUB>Jup</SUB>, and a density of 0.126 ± 0.023 ρ<SUB>Jup</SUB>. These values are consistent with those found in the literature. We also obtain a new orbital ephemeris for the system T<SUB>0</SUB> = BJD/TDB 2 454 420.447187(96) + 2.15000800(10) × E. We measured the transmission spectrum of HAT-P-32 A b and compared it to theoretical transmission spectra. Our results indicate a bimodal cloud particle distribution consisting of Rayleigh-like haze and grey absorbing cloud particles within the atmosphere of HAT-P-32 A b.STAMPAenArticle10.1093/mnras/stx31472-s2.0-85045958805000424977800088https://arxiv.org/abs/1712.00415https://academic.oup.com/mnras/article/474/4/5485/47059162018MNRAS.474.5485TFIS/05 - ASTRONOMIA E ASTROFISICA