3-D Evolution of a Thermal X-ray Loop-top Source in a Solar Flare

In this presentation we explore the 3-D properties of a thermal X-ray loop-top source in an M-class solar flare. These properties are important for understanding flare evolution and energetics, but measuring them has only recently been made possible by the launch of Solar Orbiter. Its X-ray instrument, STIX, is the first to provide solar flare X-ray imaging observations from beyond Earth-orbit. We perform 3-D reconstruction by combining stereoscopic observations from STIX and Hinode/XRT, thus revealing the temporal evolution of a thermal flare X-ray loop-top source in 3-D for the first time. In addition, we compare the 3-D derived volume with traditional volume estimates based on projected source areas and the implications for past studies. We also discuss the challenges and caveats of combining observations from non-identical instruments in this way.