Astrophysics - Solar and Stellar Astrophysics

Connecting solar flare hard X-ray spectra to in situ electron spectra. A comparison of RHESSI and STEREO/SEPT observations

*Aims.* We aim to constrain the acceleration, injection, and transport processes of flare-accelerated energetic electrons by comparing their characteristics at the Sun with those injected into interplanetary space. *Methods.* We have identified 17 …

The unusual widespread solar energetic particle event on 2013 August 19. Solar origin and particle longitudinal distribution

*Context.* Late on 2013 August 19, STEREO-A, STEREO-B, MESSENGER, Mars Odyssey, and the L1 spacecraft, spanning a longitudinal range of 222° in the ecliptic plane, observed an energetic particle flux increase. The widespread solar energetic particle …

First Solar Energetic Particles Measured on the Lunar Far-side

On 2019 May 6 the Lunar Lander Neutron & Dosimetry (LND) Experiment on board the Chang'E-4 lander on the far-side of the Moon detected its first solar energetic particle (SEP) event with proton energies up to 21 MeV. Combined proton energy spectra …