The sun "burns" hydrogen and even has "campfires" on it, but has anyone calculated a rate of actual chemical burning on the Sun? Answers to Hydrogen burning vs Hydrogen fusing explain that in astrophysics &quot;burning&quot; generally refers to nuclear fusion or at least nuclear reactions1, and information at

Why didn&#39;t we see those campfires on the Sun until now?
What could be the cause of solar &quot;campfires&quot;?

explains that those are astronomical nicknames for very small bright bits of plasma recently discovered on the Sun, not actual fires.
But in the Sun's atmosphere there may (or may not) be opportunities for chemical reactions. Certainly in some cool stars the atmosphere even makes dust.
Question: The sun &quot;burns&quot; hydrogen and even has &quot;campfires&quot; on it, but has anyone calculated a rate of some actual chemical burning on the Sun? Any oxidation reactions at all? If not our Sun, is oxidation simulated for some other stellar atmospheres?

1it's hard for me to think of two protons &quot;fusing into a diproton&quot;, later beta-decaying for example; feels more like a nuclear reaction, but maybe that's just me.
I just became curious enough to search a few keyphrases.
This article talks about hydrogen molecules acting as energy &quot;sink&quot; in the sunspots - much like water phase changes on Earth create climate features. The heat capacity, mass density, adiabatic properties of the molecular hydrogen are pretty much different from the atomic one and these are important for the convection.
Hydrogen changing between atomic and molecular form is clearly a chemical process.
The article talks even about water molecules there. Given the high temperature and low pressure, they are expected to be pretty much short-lived and oxygen constantly moving between water, hydroxyl ion or radical and oxygen atom or ion.
Related matter here

The formation of H2 can significantly alter the thermodynamic properties of the sunspot atmosphere and may play a significant role in sunspot evolution. In addition to the survey observations, we have performed detailed chemical equilibrium calculations with full consideration of radiative transfer effects to establish OH as a proxy for H2, and demonstrate that a significant population of H2 exists in the coolest regions of large sunspots.

Looks like chemical processes not only do happen on the Sun, but are of great importance for the photospheric features we see.
Do these qualify as &quot;burning&quot; is a matter of oppinion.