Neutrinos from the solar CNO cycle are detected
The Borexino collaboration reported the first direct detection of neutrinos produced by the carbon-nitrogen-oxygen cycle in the Sun, published in Nature. The CNO cycle accounts for only about one per cent of solar energy output, so the signal sits far below the proton-proton chain and required years of work on radiopurity and thermal stability of the detector to extract. Its importance is not solar: CNO is the dominant hydrogen-burning route in stars above roughly 1.3 solar masses, so this is the observational confirmation of the energy source of most of the luminous stellar mass in the Galaxy.
Observed — measured or witnessed, with the observation cited.
Subjects
- Hydrogen fusion: the proton-proton chain and the CNO cycle · phenomenon · not located
- Laboratori Nazionali del Gran Sasso · research facility · Italy
- The Sun · celestial body · Solar System · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Experimental evidence of neutrinos produced in the CNO fusion cycle in the Sun
Reports the first direct detection of solar neutrinos from the CNO cycle. Title and DOI were read from the publisher listing via search; the paper was not fetched, and the quoted ~1 per cent CNO share of solar energy output comes from accompanying institutional summaries rather than the paper.
Nature · 2020 · Partly verified
Borexino Collaboration, Nature (2020); DOI 10.1038/s41586-020-2934-0
Recorded on Hydrogen fusion: the proton-proton chain and the CNO cycle
- Payne concludes that stars are mostly hydrogen - and disclaims it
- Parker Solar Probe’s first perihelion pass
- Neutrinos from the solar CNO cycle are detected
- Parker Solar Probe passes 6.1 million km from the Sun
Related
Related because they share a subject in the Atlas — never because the text looks similar.