A star's magnetic field must be considered in order to correctly determine the characteristics of exoplanets from observations by space telescopes such as Kepler, James Webb, or PLATO. Researchers show that the distribution of the star's brightness over its disk depends on the star's level of magnetic activity. This, in turn, affects the signature of an exoplanet in observational data. The new model must be used in order to properly interpret the data from the latest generation of space telescopes pointed at distant worlds outside our Solar System.