A Small (M5) but Complex flare from Active Region 13141
Released on November 25, 2022
Solar Dynamics Observatory (SDO) operates in a geosynchronous orbit around Earth to obtain a continuous view of the Sun. The particular instrument in this visualization records imagery in the ultraviolet portion of the spectrum at wavelengths normally absorbed by Earth's atmosphere - so we need to observe them from space.
Here, Active Region 13141 (upper left of solar disk) erupts with a class M5.2 solar flare (more visible in the 304 angstrom image) and a thin stream of plasma.
The slow build-up of a solar active region erupts with an M5.2 flare and ejection of some solar material, as seen in AIA 171 Angstrom filter. The actual flare is more visible in AIA304 below. Correction is applied for the instrument Point-Spread Function (PSF).
What is the PSF (Point Spread-Function)?
Many telescopes, especially reflecting telescopes such as the ones used on SDO (Wikipedia), have internal structures that support various optical components. These components can result in incoming light being scattered to other parts of the image. This can appear in the image as a faint haze, brightening dark areas and dimming bright areas. The point-spread function (Wikipedia) is a measure of how light that would normally be received by a single camera pixel, gets scattered onto other pixels. This is often seen as the "spikes" seen in images of bright stars. For SDO, it manifests as a double-X shape centered over a bright flare (see Sun Emits Third Solar Flare in Two Days). The effect of this scattered light can be computed, and removed, by a process called deconvolution (Wikipedia). This is often a very compute-intensive process which can be sped up by using a computers graphics-processing unit (GPU) for the computation.
The slow build-up of a solar active region with an M5.2 flare erupting and ejection of some solar material, as seen in AIA 304 Angstrom filter. Correction is applied for the instrument Point-Spread Function (PSF).
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0