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Posted by neversaydie 1 day ago

Scientists discover Kelvin-Helmholtz Instability on the surface of the Sun(nso.edu)
https://www.bbc.com/news/articles/c36d4376nd2o, https://archive.is/YDn6S
186 points | 38 comments
mturmon 1 day ago|
This kind of observation is a big deal for solar physics.

It's been believed for decades that these small-scale (~100km and below) turbulent features are critical to understanding how energy dissipates in the Sun. And thus, how sunspots and flares form.

The subject has been very qualitative but is yielding on both observational and simulation fronts. I worked adjacent to this area from the 1990s-2010s, and it had been true that MHD numerical simulations of significant volumes of the Sun (but at a scale fine enough to resolve these features) were not possible. That has obviously changed!

Additionally, it had been that the best solar observatories could not quite resolve these features. In the late 1990s some of the best images came from a couple of observatories in the Canary Islands (e.g., the 1-meter Swedish telescope -- https://svs.gsfc.nasa.gov/4715/). The spatial resolution was perhaps in the ~100km range.

Of course, these are absolutely mind-boggling images. You're looking at a slice of the solar photosphere that has a temperature such that it activates a spectral line around 400nm. By isolating that wavelength, we can see what's happening at that temperature, and thus, sample a slice of the photosphere.

So, that had been the state of affairs. Now DKIST (4m aperture), with the particular instrument highlighted in OP, appears to be at a spatial resolution ~5x finer than the above imagery -- see Fig. 1c in the Nature paper (https://www.nature.com/articles/s41586-026-10871-3). It appears also (https://dkist.virtualsolar.org/vanNoortfastcam/) to be observing at 740Hz (!) for speckle reconstructions at ~1Hz.

At this scale, vortices of the flow are well-resolved -- where before you just resolved the convective cells but not the turbulent features around them. It's these turbulent features that are transporting energy.

To contextualize with respect to a HN perennial topic: DKIST (commissioned 2021) is funded by NSF, from the same pile of money that once funded Arecibo (up to 2020).

robertlucas 17 hours ago||
Thanks a lot for sharing your experience with us.

I worked adjacent to this area from the 1990s-2010s when the topic is solar physics is definitely why this forum is one of the last "places" of the internet.

mturmon 11 hours ago|||
Sure thing.

Remote sensing of the Sun is different from anything else, because you have so many photons. The idea of binning it down so fine (20x20km, 740Hz, a single nm of spectrum around a band center) is unheard of for any other target.

BobbyTables2 2 hours ago|||
Silly question but how does a 4m aperture focused onto a smaller area not concentrate the heat and melt the instruments?
esikich 2 hours ago||
It's highly filtered, you are only getting a small slice of all of the wavelengths. Only a tiny fraction of all that energy hits the photo collector. I believe the collector is also actively cooled, but I might be wrong there.
perpetuallunch 4 hours ago||
> The subject has been very qualitative

What does this mean?

CGMthrowaway 4 hours ago|||
"Qualitative" means that the field had good conceptual theories, but didn't have sufficient observational and computational resolution to determine the detailed numerical values
oxzidized 1 hour ago||
Well put. And to round out the nomenclature for those that are curious, the corollary here is that it can now become much more quantitative.
NooneAtAll3 12 minutes ago|||
quality vs quantity

seeing something new vs observing same stuff many many times to do statistics

thatoneengineer 9 minutes ago||
Good to know this is "discover" in the sense of "confirm, understand better" rather than "suddenly find out about". Otherwise this would be quite the background-tv-in-a-disaater-movie headline!
bluenose69 7 hours ago||
The Nature paper is open-access at https://www.nature.com/articles/s41586-026-10871-3 in case folks want to read the details.
inatreecrown2 3 hours ago||
Some of the images (d,e,f in Fig.1) in the nature article https://www.nature.com/articles/s41586-026-10871-3 remind me of fractals.
cf100clunk 1 day ago||
Don't look directly at them.
doodlebugging 8 hours ago||
Just get yourself a pair of these DuckDuckGo Paso Robles and enjoy the view.

https://knockaround.com/products/duckduckgo-paso-robles

eviks 20 hours ago||
You can use a protective glass built into your monitor!
sebastiennight 1 hour ago||
Instructions unclear, I just burned my Retina.
x______________ 14 hours ago||
Not to undermine how cool this is but is there any reason why we are only getting a looped 3 second video?
jdnier 6 hours ago|
Check out the last video on the page. It zooms in and you get a sense of just how much resolution there is.
nomel 1 day ago||
More direct link: https://nso.edu/press-release/nsf-inouye-solar-telescope-ena...
tomhow 6 hours ago|
We updated the main link, many thanks!
lucb1e 6 hours ago||
Eyeing that title and given the more more concrete article introduction sentence

> Scientists using the U.S. National Science Foundation Daniel K. Inouye Solar Telescope have made a major breakthrough in solar physics, discovering Kelvin-Helmholtz Instability on the surface of the Sun — a finding that could help explain explosive solar activity and other solar phenomena.

Perhaps it make sense to unclickbait the title by replacing "a hidden solar process" with "Kelvin-Helmholtz instability"

tomhow 6 hours ago||
OK, we've rewritten the title, thanks!
rootusrootus 1 day ago||
https://archive.is/YDn6S
shevy-java 5 hours ago|
The Sun impresses me. So much energy to dish out, so little of that is taken by planet Earth yet it helped yield and maintain life. Now what will happen when that energy is taken away ...
caymanjim 4 hours ago||
The sun will destroy the earth long before it stops providing energy.
perpetuallunch 4 hours ago|||
Why would the sun’s energy be taken away?
bormaj 3 hours ago||
It's the impending and inevitable heat death of the universe... several billions of years away...
beart 2 hours ago||
I think you're off by about 90 orders of magnitude for the actual heat death
Razengan 5 hours ago||
We still have our core

There may be rogue planets out there sustaining life far from any star..

apt-apt-apt-apt 2 hours ago||
There is. They had a civilization long ago, but now they're down to a small village and only have a radio that they use once every 1000 years.

I managed to talk to them a few years back on my ham. They asked me to send them energy, I told them we'd need to figure out fusion energy first and that we'd get back to them next millenium.