this post was submitted on 10 Apr 2025
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Another cloud free day in Scotland let me catch almost 9 hours of this huge and lively prom. Taken with my home made 90mm modded Coronado PST and DMK21 camera. Software: CdC, Eqmod, DSSR, AutoStakkert!, Wavesharp, DVS, Shotcut and Gimp.

David Wilson on April 8, 2025 @ Inverness, Scotland

https://spaceweathergallery2.com/indiv_upload.php?upload_id=221951

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[–] leverage 188 points 1 week ago (3 children)

The "earth to scale" really boggles my mind 🫨

[–] [email protected] 57 points 1 week ago

Thank you, I didn't even see that.

[–] [email protected] 18 points 1 week ago (2 children)
[–] [email protected] 32 points 1 week ago

It's there, you just gotta zoom in a bit.

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[–] [email protected] 79 points 1 week ago (18 children)

All that energy and here we are burning oil like cavemen in the dark.

[–] [email protected] 27 points 1 week ago (3 children)

Caveman didn't burn oil πŸ€“

[–] [email protected] 11 points 1 week ago

They might have soaked fabric or some other material in animal fat (which is just oil that's solid at room temperature), wrapped it around the end of a stick, and lit it on fire. πŸ€“πŸ€“

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[–] Texas_Hangover 10 points 1 week ago (1 children)

Well I can't ram the sun up the ass of my Silverado. Although if I outlive that thing, I'm replacing it with a horse or something. New vehicles freak me out man.

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[–] [email protected] 63 points 1 week ago (3 children)

Looks like the video is about 20 minutes of real time per 1 second of video. There are dops of plasma that fall further than the diameter of Earth in less than one in video second... which means the plasma is falling the more than the diameter of Earth in less than 20 minutes. That's close to 100,000 mph or 160,000 kph. Dang

[–] [email protected] 22 points 1 week ago

About 0.01% of the speed of light. I got a Lorentz factor of 1.00000001 so not quite fast enough for relativistic stuff.

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[–] [email protected] 63 points 1 week ago

It's crazy this guy is just doing this on his own. Looks like something from NASA to me.

[–] [email protected] 55 points 1 week ago (2 children)

So dumb question, but what’s causing the gap between the plasma cloud(?) and the surface? And is that gap filled with something that is invisible?

[–] [email protected] 86 points 1 week ago (5 children)

Plasma is electrically charged, so it interacts with magnetic lines.
The sun has magnetic field lines just as the earth does. It also rotates. But- since it's not solid, it doesn't have to rotate all at the same speed. The plasma in fast-rotating regions drags the field lines further than the plasma in slow rotating areas, creating weird loops, breaks and reconnections in the field lines. I'm almost certain that what we're seeing in this lovely bit of photography is a cloud of plasma travelling across, or trapped by one of those rogue field lines which has been pushed upwards from the surface by differential rotation.

[–] [email protected] 18 points 1 week ago

That’s fascinating. Thank you for sharing!

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[–] [email protected] 35 points 1 week ago (1 children)

The dynamics there due to sheer gravity, magnetism and levels of energy/radiation that are utterly alien to our daily experience.

[–] [email protected] 21 points 1 week ago (1 children)

I get some of the basic underlying mechanics, but I absolutely cannot comprehend it. Incredible.

[–] [email protected] 20 points 1 week ago* (last edited 1 week ago) (1 children)

A guess: doubly ionized helium vs. singly ionized helium. They absorb different amounts of radiation (have different opacity). At high opacity it gathers heat and subsequently expands. At low opacity it lets the heat pass through, subsequently cools and condenses.

(This is the mechanism that makes Cepheid stars regularly and predictably change intensity. The same mechanism is probably present in other stars too, and causes local processes that we cannot observe from another star system... but can observe in the Sun.)

Alternatively, there could be a multitude of other effects doing something similar.

[–] [email protected] 2 points 6 days ago (1 children)

This is the mechanism that makes Cepheid stars regularly and predictably change intensity

Doesn't it also make the Cepheid noticeably swell (then deflate) in circumference? Or does it maintain the same basic size, and it's just storing magnetic bubbles of hot plasma like a halo, before bursting and releasing all that accumulated material?

[–] [email protected] 2 points 6 days ago* (last edited 6 days ago)

To my understanding they do chance circumference. The opaque doubly ionized helium forms at high temperature, expands until temperature drops (change in circumference), drops to singly ionized after expansion, and gets doubly ionized again after contraction (another change in circumference). In Cepheids, it's uniform across the whole star.

Thus, your question makes me doubt my original speculation that it's helium changing ionization levels. The way some material "climbs up" into the arc in this video (from the right end, at one point of time) while other material "rains down" make a magnetic explanation (proposed by others here) seem more plausible.

[–] [email protected] 43 points 1 week ago (2 children)

This image is cool as fuck. No! Wait. This image is hot as fuck.

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[–] [email protected] 36 points 1 week ago

Absolutely amazing that you could capture that with β€œamateur” equipment, although it is clear from your post that a lot went into this. Bravo!

[–] [email protected] 30 points 1 week ago

fuckin love the fediverse

[–] [email protected] 28 points 1 week ago

God damned KDE devs at it again /s

[–] Ghyste 18 points 1 week ago

Amazing capture! Easily one of the best I've ever seen.

[–] [email protected] 18 points 1 week ago (1 children)

If the earth to scale is accurate, the drops coming to the surface might be approximately close to the land mass of a large continent.

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[–] [email protected] 16 points 1 week ago (1 children)

That is mezmerizing. Is there any way to know how big this thing is?

[–] [email protected] 30 points 1 week ago (1 children)

See ~Banana~ Earth for scale, top left?

[–] [email protected] 16 points 1 week ago

Totally missed that. Thx.

That thing is massive!

[–] [email protected] 15 points 1 week ago

We should look at the sun more. Follow me for more good advice.

[–] [email protected] 14 points 1 week ago (3 children)

Is this the actual image your camera sees? Or is it more like heat sensors visualized, or something like that?

[–] [email protected] 2 points 6 days ago* (last edited 6 days ago)

To add what the others said, this image is most likely taken with a special filter for taking only one specific wavelength, so color. In this case H-alpha, so excited hydrogen atoms, which is deep red. With this and additional filters for safety you can see more or less this image yourself, except it's red. I already had the opportunity to try this.

Here is a site showing daily images of the sun taken with different filters. Red is H-alpha, also shown in OP. Only with this filter you can see the protuberances. White is white, so what you would see if you could look directly without burning your eyes, or what you see with eclipse goggles. Right is another special Line, Calcium K. All of this you can look at with the right filters and a telescope and it looks similar to the images here, except the two colors are even more saturated than shown here. However, changes are on the order of minutes, so it looks more like an still image.

However, the sun and planets are pretty much the only object where images are similar to what you could see with telescope and filters. Colorful images of the moon are always heavily processed. For nebulas and galaxies its even more of a difference, they are just too dark to see more than a grey blob. For this a telescope does not help much, similar to a lens not helping to see in the dark. So nebulas and galaxies are shown at least hat they would look like, if they were brighter. But most of the time they are shown with a lot brighter colors than reality.

[–] [email protected] 20 points 1 week ago

"actual image your camera sees" is a term that is hard to define with astrophotography, because it's kinda hard to define with regular digital photography, too.

The sensor collects raw data on its pixels, where the amount of radiation that makes it past that pixel's color filter actually excites the electrons on that particular pixel and gets processed on the image processing chip, where each pixel is assigned a color and it gets added together as larger added pixels in some image.

So what does a camera "see"? It depends on how the lenses and filters in front of that sensor are set up, and it depends on how susceptible to electrical noise that sensor is, and it depends on the configuration of how long it looks for each frame. Many of these sensors are sensitive to a wide range of light wavelengths, so the filter determines whether any particular pixel sees red, blue, or green light. Some get configured to filter out all but ultraviolet or infrared wavelengths, at which point the camera can "see" what the human eye cannot.

A long exposure can collect light over a long period of time to show even very faint light, at least in the dark.

There are all sorts of mechanical tricks at that point. Image stabilization tries to keep the beams of focused light stabilized on the sensor, and may compensate for movement with some offsetting movement, so that the pixel is collecting light from the same direction over the course of its entire exposure. Or, some people want to rotate their camera along with the celestial subject, a star or a planet they're trying to get a picture of, to compensate for the Earth's rotation over the long exposure.

And then there are computational tricks. Just as you might physically move the sensor or lens to compensate for motion, you may just process the incoming sensor data to understand that a particular subject's light will hit multiple pixels over time, and can get added together in software rather than at the sensor's own charged pixels.

So astrophotography is just an extension of normal photography's use of filtering out the wavelengths you don't want, and processing the data that hits the sensor. It's just that there needs to be a lot more thought and configuration of those filters and processing algorithms than the default that sits on a typical phone's camera app and hardware.

[–] [email protected] 12 points 1 week ago (2 children)

Not OP, but solar photography requires super dense filters so like sunglasses alter what you see from "actual" the filters also alter the image from "actual" yet this is what would "actually" be "seen" by the camera. So yes and no depending how you want to interpret "actual".

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[–] [email protected] 14 points 1 week ago* (last edited 1 week ago)

For comparison the distance from the plasma cloud to the sun's surface is about how far communication satellites in geostationary orbit are above Earth.

I know all kinds of nerdy things.

[–] [email protected] 13 points 1 week ago

It’s like raiiiiiiiaaaaaiiiiiiiin…

Cool shot!

[–] [email protected] 11 points 1 week ago (1 children)

Another cloud free day in Scotland let me catch almost 9 hours of this huge and lively prom.

As soon as I read the word "Scotland", my brain went back and revised this to be read in Scott Manley's voice.

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[–] [email protected] 10 points 1 week ago

This is beautiful

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