Solar Radio-Frequency Reflectivity and Localization of FRB from Solar Reflection
Abstract
The radiation of a Fast Radio Burst (FRB) reflects from the Moon and Sun. If a reflection is detected, the time interval between the direct and reflected signals constrains the source to a narrow arc on the sky. If both Lunar and Solar reflections are detected these two arcs intersect, narrowly confining the source location on the sky. A previous paper calculated reflection by the Moon. Here we calculate the reflectivity of the Sun in the "flat Sun" approximation as a function of angle of incidence and frequency. The reflectivity is high at frequencies 100\,MHz and grazing incidence (angles 60), but exceeds 0.1 for frequencies 80\,MHz at all angles. However, the intense thermal emission of the Solar corona likely precludes detection of the Solar reflection of even MJy Galactic bursts like FRB 200428.