Infographic showing the path of stellar light through the atmosphere of WASP-19b

As WASP-19b passes in front of its parent star, some of the starlight passes through the planet’s atmosphere and leaves subtle fingerprints in the light that eventually reaches Earth. By using the FORS2 instrument on the Very Large Telescope the team was able to carefully analyse this light and deduce that the atmosphere contained small amounts of titanium oxide, water and traces of sodium, alongside a strongly scattering global haze.