Following the TraCS of exoplanets with Pan-Planets: Wendelstein-1b and Wendelstein-2b

Hot Jupiters seem to get rarer with decreasing stellar mass. The goal of the Pan-Planets transit survey was the detection of such planets and a statistical characterization of their frequency. Here, we announce the discovery and validation of two planets found in that survey, Wendelstein-1b and Wendelstein-2b, which are two short-period hot Jupiters that orbit late K host stars. We validated them both by the traditional method of radial velocity measurements with the HIgh Resolution Echelle Spectrometer and the Habitable-zone Planet Finder instruments and then by their Transit Color Signature (TraCS). We observed the targets in the wavelength range of 4000−24 000 Å and performed a simultaneous multiband transit fit and additionally determined their thermal emission via secondary eclipse observations. Wendelstein-1b is a hot Jupiter with a radius of $1.0314_{-0.0061}^{+0.0061}$ RJ and mass of $0.592_{-0.129}^{+0.165}$ MJ, orbiting a K7V dwarf star at a period of 2.66 d, and has an estimated surface temperature of about $1727_{-90}^{+78}$ K. Wendelstein-2b is a hot Jupiter with a radius of $1.1592_{-0.0210}^{+0.0204}$ RJ and a mass of $0.731_{-0.311}^{+0.541}$ MJ, orbiting a K6V dwarf star at a period of 1.75 d, and has an estimated surface temperature of about $1852_{-140}^{+120}$ K. With this, we demonstrate that multiband photometry is an effective way of validating transiting exoplanets, in particular for fainter targets since radial velocity follow-up becomes more and more costly for those targets