Bridging astrophysics and heliophysics: observing high-energy solar flaring activity to understand stellar flares

Understanding high-energy aspects of flaring activity on the Sun can help to understand the capability of other stars to support life or to wipe it out (or both!). This includes understanding the effects of solar and stellar flares on planetary atmospheres, such as radiation levels changes (particularly high-energy photons and energetic particles) at the surfaces of planets in the habitable zone. To better merge what is known about flares on the Sun and on other stars, and their effects on other planets, multidisciplinary efforts will be needed that span solar, heliospheric, magnetospheric, ionospheric, planetary, and stellar physics. High-energy measurements will play a key role. Within the area of solar flare investigation, efforts are needed to better characterize the entire flare frequency distribution and place these within the context of flare distributions measured on other stars. This includes studying large flares that could cause abrupt damage all the way down to nanoflares, which could be influential due to the power in numbers. High-energy measurements of flares (especially those observed in hard and soft X-rays, EUV, and radio) are among the measurements that can be compared with stellar studies. It should be noted that stellar flares usually have far inferior multiwavelength coverage than solar flares do, and hard X-ray stellar flare observations are particularly rare. A concerted effort should be made to garner thorough multiwavelength studies of individual high-energy solar flares and of solar flare distributions, along with the development of models that can be applied to other stars (with tuned parameters and with constraints from stellar observations). The development of analysis methods that can be utilized for both solar and stellar measurements is also required. Lastly, an effort will need to be made to bridge heliophysics and astrophysics communities in order to leverage the full capability of this line of inquiry.