A solar flare is a rapid release of magnetic energy in the solar atmosphere, observed as enhanced radiation and often accompanied by plasma heating and particle acceleration. Emission spans many wavelengths, with different bands tracing different stages and particle populations. A solar flare and a coronal mass ejection can accompany the same eruption, but radiation enhancement and expulsion of magnetized material describe different phenomena.[ref]
Overview of Solar Flares by NASA. Magnetic-energy release, plasma heating, acceleration and multiwavelength signatures
A simple energy scale comes from the magnetic energy density, . A hypothetical region with and volume containsThis is an illustrative field-energy budget, not a measured flare yield. Only the releasable part of the field energy can power an event; geometry and the final magnetic state matter.
Monitoring depends on the instrument. GOES X-ray sensors measure the Sun's irradiance in specified passbands, including –. Their time series can locate the rise and peak of an event, while X-ray images locate emitting regions on the solar disc. NOAA's operational event end uses a prescribed fall from peak towards background, so a reported duration is partly a measurement convention.[ref]
GOES X-ray Flux by NOAA Space Weather Prediction Center. Details and event definitions: passbands, one-minute sampling and halfway-to-background end criterion
Soft X-rays commonly trace heated plasma, while hard X-ray signatures can track energetic electrons. Comparing their time profiles tests how rapidly released magnetic energy reaches particles and heat. A single bright image or peak flux cannot by itself provide the total energy released in every channel.[ref]
Overview of Solar Flares by NASA. Time-profile comparison of soft X-rays, hard X-rays and gamma rays
Articles by others on the same topic
A solar flare is a sudden, intense burst of radiation from the sun's surface, typically associated with the release of magnetic energy stored in the sun’s atmosphere. These events occur in active regions, often near sunspots, and can release a wide spectrum of electromagnetic radiation, including radio waves, visible light, ultraviolet light, and X-rays. Solar flares are caused by the complex interplay of magnetic fields in the sun.