Physics

Nanoflares

Solar flare

Sunspot

Corona (planetary geology)

Magnetization

Laser

Magnetic field

Optics

Solar wind

Astronomy

Extreme ultraviolet

Magnetic energy

Venus

Flare

Magnetic reconnection

Magnetohydrodynamic drive

Astrophysics

Quantum mechanics

Computational physics

Magnetohydrodynamics

Coronal mass ejection

Radiative transfer

Astrobiology

Nature Astronomy

Solar and stellar flares are the most intense emitters of X-rays and extreme ultraviolet radiation in planetary systems1,2. On the Sun, strong flares are usually found in newly emerging sunspot regions3. The emergence of these magnetic sunspot groups leads to the accumulation of magnetic energy in the corona. When the magnetic field undergoes abrupt relaxation, the energy released powers coronal mass ejections as well as heating plasma to temperatures beyond tens of millions of kelvins. While recent work has shed light on how magnetic energy and twist accumulate in the corona4 and on how three-dimensional magnetic reconnection allows for rapid energy release5,6, a self-consistent model capturing how such magnetic changes translate into observable diagnostics has remained elusive. Here, we present a comprehensive radiative magnetohydrodynamics simulation of a solar flare capturing the process from emergence to eruption. The simulation has sufficient realism for the synthesis of remote sensing measurements to compare with observations at visible, ultraviolet and X-ray wavelengths. This unifying model allows us to explain a number of well-known features of solar flares7, including the time profile of the X-ray flux during flares, origin and temporal evolution of chromospheric evaporation and condensation, and sweeping of flare ribbons in the lower atmosphere. Furthermore, the model reproduces the apparent non-thermal shape of coronal X-ray spectra, which is the result of the superposition of multi-component super-hot plasmas8 up to and beyond 100 million K. A state-of-the-art magnetohydrodynamic simulation of a solar flare from emergence to eruption is able to reproduce observations at visible, UV and X-ray wavelengths, and suggests that non-thermal particles at high energy may play a less prominent role than usually assumed in flare models.

A comprehensive three-dimensional radiative magnetohydrodynamic simulation of a solar flare