My imaging: image file is big, zoom in to see anything closer up
There are three sets of solar prominences along the limb, and another one associated with the sunspot on the surface. This image used brightness inversion on the solar disk, thus both prominences on the limb and surface (the latter are called filaments) will appear bright, as will surface sunspots.
This video of 20 frames was created from images taken on July 10th over about 51 minutes. The individual frames of the animation were all from 90 second SER videos at 1600x1600 pixels in 16 bit mono (the camera is 14 bit) taken at 18 fps. Each video was separated by a delay of 90 seconds. The resulting 1600 frames were stacked in Autostakkert as the best 20%, so just over 300 frames were used in each of the final animation frames. Each animation frame was then wavelet sharpened with Registax. The final gif was produced in Photoshop, including adding color.
For those that missed my last post, I’m including again my Top 10 things to see in Solar Ha. Our Sun in Ha has so many interesting features that it challenging to understand exactly what one is seeing. I compiled this summary of as a viewing aid for myself, hopefully you may find it useful too. Again note, on the surface in my image, light is dark and dark is light.
A layman’s guide to the “Top 10 things to see in Solar Ha.”
In white light we only see the Sun’s 6000 Kelvin photosphere “landscape”, consisting of:
• Darker, cooler sunspots
• Granulation, consisting of hotter and brighter rising; and cooler and darker sinking convention cells, like boiling porridge.
• Faculae, bright hot patches of concentrated magnetic flux.
It is the chromosphere that shows up In Ha, as we block out the Photosphere’s overwhelming white light. The chromosphere is a much hotter, 2000 km thick layer, lying above the Photosphere. With temperatures rising to 17000 K, the chromosphere efficiently excites hydrogen to produce Ha emission.
The chromosphere shows a very different “landscape” than the Photosphere:
• Spicules, tiny bright spikes, form a 3,000-10,000 km layer of bright fuzz on the Sun’s limb, and darker spikes on the solar disk. They are dark on the disk as they are cooler than the chromosphere below them. Few last more than 15 min, but the Sun has 100s of thousands of them at any one time.
• Fibrils are tiny low contrast darker filament-like structures.
• Dark Mottles, comprised of fibrils and spicules, blanket the entire disk.
• Field Transition Arches are groups of longer fibrils that join areas of opposite magnetic polarity.
• Prominences loop out from the limb: these are glowing, but cooler, hydrogen gas lifted from the Sun by magnetic fields. Prominences rise 100s of thousands of km above the hotter chromosphere.
• Filaments are the darker clouds that seem to float on the solar disk. Filaments are prominences, appearing darker because they are cooler and higher, extending above the hotter chromosphere below them.
• Plage (French for beach) are irregular, bright patches on the solar disk, found around active regions. They mark nearly vertical emerging or reconnecting magnetic fields and can last several days.
• Ellerman bombs (named for the astronomer who studied them) are tiny, brighter spots that fluctuate in brightness, associated with large plage.
• Flares show a brightening within a sunspot group, often with a “comb-like” flow. They last from a few minutes to hours and change in both intensity and area as you watch.
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