Italy’s Borexino detector has confirmed a decades-old theory, finding the first-ever evidence of a carbon-nitrogen-oxygen (CNO) cycle that produces neutrinos in our Sun. The researchers call this a historic achievement, one confirming an 80-year-old theory about the star and shedding light on the ‘dominant channel in the universe for hydrogen burning.’
The study, which was recently published in Nature, comes from the Gran Sasso National Laboratories of the Italian National Institute for Nuclear Physics. The Borexino team previously studied the proton-proton-chain, the main way energy is produced in the Sun. The research was made possible by detecting the neutrino fluxes originating from the proton-proton-chain cycle.
A similar effort went into the CNO study, with the researchers explaining that they measured neutrinos resulting from this cycle, publishing the first experimental evidence that this ‘additional energy generation mechanism’ is taking place on our star. The groundwork for this finding was laid 30 years ago in 1990 and was preceded by more than a decade of research involving the Sun’s physics, among other things.
The Borexino detector is the result of a scientific collaboration that included involvement from the University of Milan and the University of Princeton. The ultra-sensitive detector was key to the findings, according to the INFN, which explains that Borexino is very radio-pure due to its onion-like design involving many layers.
As a result, the experiment is able to detect neutrinos that pass through Earth without disruption. The researchers say detecting the neutrinos confirming the CNO cycle was ‘a complicated task,’ but one ultimately made possible with the detector, software, and many experts working together.