Quite a nice surprise to see during my morning commute! Everyone here is extremely pleased to see how the images turned out. Very impressive work from DKIST
These images seem to have a sort of “enhanced blurring” and depth-flattening reminiscent of early 3d ultrasounds.
Am I interpreting that right? Or is the surface of the sun really like that?
I've also found some interesting bonus footage of the camera in a test setup for those that are curious (the actuating gray box in the background) [2]
[1] https://www.nso.edu/wp-content/uploads/2020/01/MediaKit.zip (1.25GB)
Would way prefer people link the original sources in cases like this, where the news articles add almost nothing useful and instead bombard me with advertisements and user-tracking, etc.
Maybe posts should have the ability to submit different URLs for mobile vs desktop? (I know that idea is problematic in multiple ways).
Brb, i am grabbing a spoon and i'll find the one who ordered this 'feature'..
But seriously - dropping a primary sources would be a neat habit to have in here :)
Congrats to all involved, and kudos for ushering in a new golden age of solar observations
At first glance of the static image, it appeared to me the granular structure of solar surface convection resembled a thousand other phenomena in Nature: poly-crystalline grain boundaries in metal alloys, lipid cells in fatty tissue, colloidal suspensions of cloud smoke
But watching the animation made me realize how unique and dissimilar this is to any other chaotic turbulent flow
Due to the sun's gargantuan scale, even throwing the world's fastest supercomputers at the problem, we cannot adequately simulate all the convection, plasma, rotation and magnetic interactions of solar surface and interior dynamics
These images make me feel very humbled, reminding us of our place in the cosmos!
Weak influence of near-surface layer on solar deep convection zone revealed by comprehensive simulation from base to surface
Though the misconception really is pervasively widespread, even among first-tier astronomy graduate students, so perhaps there might now be a degree of confusion present as well. And a (very) few instances of colorization are representationally valid, if unfortunate in their collateral damage, as when representing that some instrument's sampling band is in yellow.
After 20 or so minutes poking around, I'm not 100% sure what instrument took the images in the OP. There are five focal planes that can get the light from this much-anticipated solar telescope, which has been envisioned and prototyped going back at least 20 years.
Anyway, I think the instrument for the images was VBI, the Visible Broadband Imager (https://www.nso.edu/telescopes/dkist/instruments/vbi/). It takes images in 8 spectral bands, in the visible range. But these bands are very narrow, like 0.5nm or less. (Solar astronomy is cool that way, lots of photons of whatever energy you want.) The specific bands have been carefully selected.
One band that page calls call "continuum" (sometimes referred to as "pseudo-white-light", found in the "spectral resolution" submenu) is at 450nm, in the blue. All the 8 various bands illustrate activity at different altitudes in the solar atmosphere. The 450nm band will be from the solar photosphere, where sunspots and other familiar features live. Some others are much higher up, and sunspots will not be present as such in those bands.
If this conjecture is true, the displayed images are taken in a very narrow slice of spectrum around 450nm (or another one around 668nm, which is in red) and then mapped through a black/orange/yellow/white color map for display. This kind of "colorization" is pervasive throughout solar astronomy, and used universally by astronomers themselves for their own science images. (Visit https://umbra.nascom.nasa.gov/newsite/images.html and weep.)
As hinted in your last sentence, it's not at all clear what a "correct" colormap for light from 450nm +/- 0.5nm should be. Shades of blue?
For more on your point: http://solar-center.stanford.edu/SID/activities/GreenSun.htm... (old-fashioned site, but technically 100% solid).
Even first-year undergraduate astronomy students dont't think a star "is a colour" considering the useful information when dealing withs come from spectra, not photos.
Stellar classification on an H-R diagram is a convenience, that is all. It's already acknowledging "colour shift" from the Doppler effect (aka "red shifting"), but every first-year astronomy undergrad knows no two stellar spectra are the same, none are a single wavelength, and "white light" is a perceptual phenomenon not a physical one.
G-class stars like the sun are called yellow dwarfs, which is also inaccurate.
Turns out a person on Mars would sometimes see a bluish sky depending on how much suspended dust is present, the altitude, and the time of day.
The importance of your "misconception" is unclear to me, most people have seen the sun for themselves (though I expect all have been told not to look) and can tell the difference between the real thing and a picture of it.
Seeing as white is just "full spectrum", that is literally just the definition of white. So yes, the sun is white.
As usual a deeply knowledgeable and enthusiastic set of guests and they were talking about this telescope and several other probes launched and due to be launched
well worth it
Are they actually making a swimming pool's worth of ice cubes that are "emptied" into these tanks? I looked at the wikipedia page [0] for more information but there's no mention of the cooling system.
It sounds like a major part of the interesting engineering challenge, strange to not find photos or even a description of the cooling system's design.
[0] https://en.wikipedia.org/wiki/Daniel_K._Inouye_Solar_Telesco...
Notably, the telescope enclosure is actively cooled to mitigate thermal seeing effects.
Edit: change "radii" to "diameters"
sun diameter = 1.3927 million km
Betelgeuse diameter = 1.234 billion km
Betelgeuse diameter / sun diameter = 886 > 100
https://www.wolframalpha.com/input/?i=1+au+%2F+radius+of+the...
Solar radius = 700000km Mean distance of Earth from sun = 1AU = 1.5e8 km = 214.3 solar radii.
From Earth, solar radius = 0.25 degrees. 233 solar radii in 1 radian.
> From Earth, solar radius = 0.25 degrees. 233 solar radii in 1 radian.
I don't understand this. I think I understand that the sun would take up 0.5 degrees of the "view" (I don't have a good word for this) when looked at from Earth, so radius is 0.25 degrees. But how does the second statement follow? I get that a radian is about 57.3 degrees, so 57.3 / 0.25 = 230, but why why does 1 radian make sense to use here?
Sunshine, perhaps? https://en.wikipedia.org/wiki/Sunshine_(2007_film)
Brilliant, brilliant film. The premise is shonky as they come but it's obvious that the film itself has little to do with the premise. Awesome acting, literally-awesome SFX (their ability to give the sun so much weight is amazing, you really get a sense of an immortal unstoppable force), and a message that's neither shallow nor deep but prompts some self-reflection in ways you don't expect.
It does, though not being a rigid body, the rate of rotation is a function of latitude. Near the equator, the period of rotation is ~24 days. As you near the poles, the period is closer to 30-35 days. A means of measuring these rates available to backyard astronomers is through measuring the positions of sunspots over time. [1]
[1] Please don't look at the sun through a telescope or really at all without knowing what you're doing and taking appropriate precautions: https://www.youtube.com/watch?v=R9cMXCemoJI
Here's a really old picture that is at essentially the same scale as what the BBC decided to show, but made in 1997: https://en.wikipedia.org/wiki/Swedish_Vacuum_Solar_Telescope...
https://www.nso.edu/wp-content/uploads/2020/01/full_image_wi...
That image covers an area 2.5x the size of Earth, but it's showing less than 0.1% of the Sun.
I wonder what the speed of sound is in the solar medium, at the ambient temperature and pressure.
Is that really a "mystery"?
I mean, you can easily create plasma in a microwave oven, and the magnetron doesn't get very hot.
The ideal gas law dictates these amazing structures of the solar atmosphere. But.... incredible cosmic magnetic powers influence these structures in the solar atmosphere... That we still can't explain.
Later I hope to discover alien life in the distributions of charged particles and their induced magnet fields... I may need to aquire another degree in the mean time.
#fields #studyhard
It also has an amusing ship mind, which presents as a young male sociopath: "Falling Outside The Normal Moral Constraints".
