Analysis of Solar Flare Observations obtained by the MinXSS-1 CubeSat

Authors: Christopher S. Moore (Harvard|Smithsonian Center for Astrophysics), MinXSS Team

Solar flares accelerate particles on timescales of minutes, converting magnetic energy to thermal, radiative and kinetic energy through magnetic reconnections. As a result, local plasma can be heated to temperatures in excess of 20 MK. These flares emit high energy electromagnetic radiation, such as soft X-rays (sxr). The elemental abundance of low first-ionization potential (FIP) elements have been observed  to be depleted during solar flares. The Miniature X-ray Solar Spectrometer CubeSat-1 (MinXSS-1) provides disk-integrated solar spectra in the 1-12 keV energy range with a nominal 0.15 keV full-width at half-maximum (FWHM) resolution at 5.9 keV and a cadence of 10 seconds. During the year-long mission of MinXSS-1,  ~30 flares were observed ranging from C to M class. We examine the time evolution of temperature, emission measure, and elemental abundances of Fe, Ca, Mg, Si, and S with CHIANTI spectral models and MinXSS-1 data. We present that low FIP elements are near photospheric values during the peak of the flare. This corroborates that during a solar flare, the lower atmospheric plasma fills the coronal loops due to chromospheric evaporation.