You have mentioned a neat point that illustrates some of the complexity of an "image" like the ones shown.
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?
Comments
You have mentioned a neat point that illustrates some of the complexity of an "image" like the ones shown.
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).
The source article[0] linked in another thread says the images are of the 789nm band.
[0] https://www.nso.edu/inouye-solar-telescope-first-light/