The Active Christmas Eve 2023 Ultraviolet Sun

  • Released Friday, February 16, 2024
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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.

Solar Dynamics Observatory (SDO) observes a very active hemisphere of the Sun on Christmas Eve 2023. No significant flares - just fifteen hours of small eruptions, bright coronal loops, dark filaments hovering above photosphere, and other small-scale phenomena in the life of a star evolving towards the peak of it's activity cycle.

The point-spread function correction (PSF) has been applied to all this imagery.

This view of the Sun, through the SDO/AIA 171 angstrom filter, reveals the flows of hot plasma along the magnetic field lines, glowing from the emission of light by ionized iron atoms which have lost eight electrons (aka Fe IX).

This view of the Sun, through the SDO/AIA 193 angstrom filter, reveals some hotter regions of the chromosphere and active region, and enhances visiblity of the less dense outflowing material in coronal holes. This filter corresponds to emission from iron atoms that have lost eleven electrons (Fe XII) and 23 electrons (Fe XXIV).

This view of the Sun, through the SDO/AIA 211 angstrom filter, reveals hot active regions. This filter corresponds to emission from iron atoms that have lost thirteen electrons (Fe XIV).

This view of the Sun, through the SDO/AIA 304 angstrom filter, reveals the upper chromosphere and prominences, especially off the solar limb. This filter corresponds to emission from helium atoms that have lost one electron (He II).




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.
Time slates for the multiple movies above, for custom compositing. Make sure to match the event and frame tag for the SDO frames you are using.

Time slates for the multiple movies above, for custom compositing. Make sure to match the event and frame tag for the SDO frames you are using.

Credits

Please give credit for this item to:
NASA's Scientific Visualization Studio

This page was originally published on Friday, February 16, 2024.
This page was last updated on Monday, February 12, 2024 at 5:15 PM EST.

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