Presentation #313.09 in the session “Solar Physics Division (SPD): Instrumentation and Active Regions”.
The solar PolArization and Directivity X-Ray Experiment (PADRE) is a 12U Cubesat observatory that will observe the Sun in hard X-ray (HXRs) from low earth orbit. PADRE will investigate the accelerated electron angular distribution in solar flares with two unique and complementary approaches (1) by making spatially-integrated spectro-polarimetric x-ray measurements (~10–100 keV) and (2) by coordinating with Solar Orbiter/STIX to make the first two point measurements of x-rays and determining their directivity. We present the PADRE observatory concept, its science objectives and design. We will discuss the type of observations that will be made by the SHARP and XDSOX instruments. Spectro-polarimetric observations will provide unique information of the electron angular distribution. Furthermore, STIX on board Solar Orbiter will perform X-ray observations of solar flares from 0.28 AU (at perihelion) to 1.2AU (at aphelion) and up to inclinations of ∼25 degrees at heliospheric angles significantly different from the Earth. This provides a unique opportunity to make stereoscopic X-ray observations and measure the electron anisotropy of individual flares confidently for the first time. PADRE has one science objective: determine the angular distribution of accelerated electrons from standalone and joint SolO/STIX observations. This will allow the determination of the angular distribution of flare-accelerated electrons.