All light, heat, and the solar wind comes from the chromosphere.
Surface of the sun (photosphere) at 9500° is a fraction (200 X less) of the millions of degree heat thousands of miles above it in the chromosphere. It was a theory by Parker, whom the probe was named after https://en.m.wikipedia.org/wiki/Eugene_Parker
that electrical currents following the path of least resistance exited into the chromosphere resulting in the Sun’s brilliance. Spectral analysis of sunlight verifies it.

After launching of the Soho (solar observatory) The British solar scientist wrote a book about the amazing observations of micro flares and the electrical phenomenon that heats the chromosphere to over 2,000,000° and hotter. I listened to him live on a BBC interview, then years later found it on the way back machine and listen again, wondering why this new discovery wasn’t being shouted from the mountain tops!

Nuclear scientists insist that the sun’s heat is from hot Fusion and came up with models to reproduce this theory on earth making clean power, ignoring the reality that the byproducts of Fusion (including gamma rays, most of which pass right through the earth) are nearly nonexistent. At the minimum a “factor of three” less then should be present under known physics of fusion which would be enough to sterilize the solar system. After tens of billions of dollars spent on Fusion related energy boondoggles, none came close to producing energy.
It turns out that their money scam was based upon a faulty model, imagine that.

Others begin publishing real science;
https://www.thehindu.com/todays-paper/tp-features/tp-sci-tech-and-agri/suns-micro-flares-play-major-role-in-heating-corona/article28511673.ece

Pictures of x-ray micro flares 2007 (The small one is hard to see at only 2000 km across)https://spacemath.gsfc.nasa.gov/weekly/4Page3.pdf

Then they change the name to “nano flares”. Do a search and you’ll see all kinds of movies and models associated with it.
A excellent article explaining the science as a prelude in 2015 to the launch of the solar probe. What they hope to learn.
https://science.nasa.gov/science-news/science-at-nasa/2015/19mar_nanoflares

This information will change everything we know about the sun including the lifecycle of the sun. The sun does not burn mass, does not burn out.

Where does the heat come from? The science has it right that the more massive the sun became, the hotter it became. Then they say it became so hot that Fusion occurs… it didn’t, so that just leaves intense gravity creating heat and pressure “friction” which results in plasma with electrical currents, magnetism, light and everything else that we are observing.
The sun is a extreme model of what we just learned about Jupiter creating plasma at the transition zone below its atmosphere, which not only makes it extremely hot causing the storms, but it’s intense magnetic field as well. Jupiter emits far more heat than it receives from the sun.

The old theory is the sun becomes lighter as it burns and transforms its mass into energy.
I have a scientific paper written in the 1890s which has calculated how much coal the sun would have to burn to maintain its constant heat and light. “9 feet of coal over its entire surface every hour”.
Wikipedia still has the old wives tale that hasn’t been changed in over 50 years;

“The Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. This energy, which can take between 10,000 and 170,000 years to escape from its core, is the source of the Sun’s light and heat. When hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand, eventually transforming the Sun into a red giant.”

10,000 years to migrate from the core to the surface? Radiation that isn’t blocked, (like neutrons) moves at the speed of light. With our instruments we can see where it moves from and it’s not the core. Just as the heat and light comes from outside of the sun in the corona sphere!
Is this an example of settled science? Why is the priesthood so resistant to change? Why is it so dangerous that the public know the truth? Is it similar to teaching the earth is flat to keep sailors from trading with neighboring countries?
Would Congress withhold billions from fusion science?

(Plato gave his students hypothesis that the earth was round because the shadow of Earth on the moon was circular.
Re-creating the arc of the shadow with a stick and string, he determined the earth was four times larger than the moon)(measuring the angle of the shadow in a well in Alexandria, famous mathematician determine the diameter of the earth 200 years before Christ)

10 years ago, there used to be a dozen theoretical problems listed on the theories surrounding the sun. I just checked, and all but two have been removed. If the truth will make you free… Then the slavery of thought is the purpose.
https://en.m.wikipedia.org/wiki/Sun