The HAWC detector (2014) [image credit: Jordanagoodman @ Wikipedia]
In a related Phys.org article a researcher says: “The sun is more surprising than we knew. We thought we had this star figured out, but that’s not the case.” But it has long been known that cosmic rays go up when solar activity goes down, and vice versa.
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Observations over the past decade or so have shown that the Sun emits many more gamma rays at GeV energies than is expected from modeling, says APS Physics.
Now a collaboration operating the High-Altitude Water Cherenkov (HAWC) Observatory in Mexico show that this gamma-ray excess extends up to TeV energies [1].
This finding has implications for our understanding of both stellar atmospheres and astroparticle physics.
Solar gamma rays are produced when high-energy particles called cosmic rays head toward the Sun’s surface but are turned around by the solar magnetic field. As these particles then travel away from the Sun’s surface, they interact with gas in the solar atmosphere to create gamma rays.
Models predict the number of emitted photons of a given energy by assuming certain properties of the cosmic rays, the Sun’s magnetic field, and the solar atmosphere.
The HAWC Collaboration presents the first detection of TeV gamma rays from the Sun, a finding based on more than six years of data. The flux is much higher than predicted, indicating that the interactions between the cosmic rays and the solar atmosphere are remarkably efficient at producing gamma rays.
Moreover, the TeV-gamma-ray flux varies in inverse proportion to the level of solar activity, suggesting that the Sun’s magnetic field affects the flux—a result that will be useful for modeling.
The researchers say that their work calls for a revised theoretical framework that can explain the excess of solar gamma rays at both GeV and TeV energies.
Source here.
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[1] A. Albert et al. (HAWC Collaboration) – “Discovery of gamma rays from the quiescent Sun with HAWC”, Phys. Rev. Lett. 131, 051201 (2023).
Tallbloke's Talkshop 
AUGUST 3, 2023
Scientists discover the highest-energy light coming from the sun
The gamma rays that Nisa and her colleagues observed had about 1 trillion electron volts, or 1 tera electron volt, abbreviated 1 TeV. Not only was this energy level surprising, but so was the fact that they were seeing so much of it.
. . .
Now, for the first time, the team has shown that the energies of the sun’s rays extend into the TeV range, up to nearly 10 TeV, which does appear to be the maximum, Nisa said.
Currently, the discovery creates more questions than answers. Solar scientists will now scratch their heads over how exactly these gamma rays achieve such high energies and what role the sun’s magnetic fields play in this phenomenon, Nisa said.
https://phys.org/news/2023-08-scientists-highest-energy-sun.html
Probably not anything new to those engineers who design solar arrays for satellites and system probes.
“TeV-gamma-ray flux varies in inverse proportion to the level of solar activity, suggesting that the Sun’s magnetic field affects the flux.”
Too early to tell. We will need data for at least two solar cycles. BTW, wasn’t it an assumption in the first place?
Broadly speaking cosmic rays reach a high around solar cycle minimum, and a low around the maximum when the solar wind is strongest.
https://cosmicrays.oulu.fi/ (scroll down to monthly averages, last chart in the link).
As the abstract says ‘current theoretical models are unable to explain the details of how solar magnetic fields shape these interactions. HAWC’s TeV detection thus deepens the mysteries of the solar-disk emission’, I’ve added a ‘baffled scientists’ tag to the blog post.
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.051201
Plus the reference in the phys.org link to ‘scratching their heads’.
[…] Record-Breaking Detection of Solar Photons […]
So another load of dodgy “models” based on incorrect assumptions bite the dust…
Don’t you just love all this “settled science?
“Science is the belief in the ignorance of the experts” – Richard Feynman
Yes Cat, In fact no one has defined what is a photon. A nobel prize winning physicist (1955) said photons do not exist. Every radiation concerns waves of various wavelength. Gamma rays are waves of very short wavelength. UV has a wavelength about 0.4-0.5 micron. Normal light from the sun has an average wavelength of 0.7 micron. Infrared radiation starts at about 1 micron and extends to about 7 micron. Long wave radiation starts about 8 micron and goes out to about 40 micron. The earth emits radiation in the range of 9 to 11 micron (around 288K). CO2 only absorbs longwave radiation around 14.8 micron which by Wien’s displacement law is about 200K. CO2 can not radiate back to Earth, from its absorption from the Earth surface. Methane only absorbs radiation in the range 6-8 micron wavelength. It does not absorb any radiation from the Earth surface and nothing significant from the sun. Global warming is natural due to the sun and cloudformation which are aided by or determined by incoming gamma rays.
Re-photon, the physicist mentioned above is Willis Eugene Lamb Jr who won the Nobel prize for Physics in 1955. Has anyone seen a definition of a photon? Are there infinite of types of photos at every fraction of wavelength? Do you know that Albert Einstein said “Two things are infinite the universe and human stupidity and I am not sure about the universe”
Another saying from Richard Feyman “There was a time when the newspapers said that only twelve men understood the theory of relativity. I do not believe there ever was such a time.” and “I think I can safely say that nobody understands quantum mechanics.”
These are Lamb’s words “that the author does not like the use of the word
“photon”, which dates from 1926. In his view, there is no such thing as a photon. Only a comedy of errors and historical accidents led to its popularity among physicists
and optical scientists.
I suggest wrong assumptions as with all climate science articles.
Heh, is it a particle or a wave?
If you set up a Young’s slits experiment and fire individual photons (quanta?) at it how do they all “know” which slit to go through to produce the interference pattern, even if they haven’t been sent off yet?
What fun!
“The researchers say that their work calls for a revised theoretical framework that can explain the excess of solar gamma rays at both GeV and TeV energies.”
confirmed in 2019. https://en.wikipedia.org/wiki/Ultra-high-energy_gamma_ray.
How about not a ‘revised’ but a new theoretical framework? viz: even normal gamma rays come off the sun mostly at an angle. Evidence the sun has to have a surface (not be plasma): PM Robitaille 2013 http://www.ptep-online.com/2013/PP-33-L1.PDF
“they exhibit a powerful anisotropy best explained by invoking a true photospheric surface”
When wearing my heretic hat I suspect the consensus opinion of photons is also wrong. some spin-triple-tumble model (like, you know) for gamma rays as = double tumbles at speed c, but normally triple-tumbles <c. only w the outmost tumble nearing full c, would there be Tev energies, and under only certain conditions. w gaseous plasma hardly likely be one of those conditions.
ichor, a little off topic but this is a fuller explanation P.-M. Robitaille and D. Rabounski. Polarized Light from the Sun, Volume 11 (2015) PROGRESS IN PHYSICS Issue 3 (July)
(It would interesting to find out what AI chat has to say. I have got AI to say that at every point of heat transfer eg refrigeration, that the 2nd law of thermodynamics applies. That overturns the possibility of CO2 heating the Earth surface and causing warming. Also no such thing as net heat flow)
Commenter Catweazle gets quoted at SIS…
Cosmic Rays and the Sun
5 August 2023
https://www.sis-group.org.uk/news/2023/08/05/cosmic-rays-and-the-sun/
[…] Posted on August 9, 2023 by HiFast Record-Breaking Detection of Solar Photons […]