Solar Neutrinos

How do we know what is happening inside our beloved Sun?

We can study the Sun’s interior through three different ways and one of them is through observations of solar neutrinos produced by the nuclear fusion that power the Sun.

The nuclear fusion of proton and proton in the Sun produce deuterium, positron, neutrino that is responsible for almost 100% of the energy production by our Sun. Solar neutrinos contributes the largest flux of neutrinos from natural sources observed on Earth when make a comparison with atmospheric neutrinos and etc.

neutrinos are made in the first step of the chain reaction
Nuclear Fusion By Astronomy Notes

In principle, solar neutrinos give us the most direct way to study the nuclear fusion in the Sun’s core. This is because almost all of them pass straight through solar interior into space. However, neutrinos are difficult to detect but still possible since they do occasionally interact with matter and this could be done by using large detector.

Image result for solar neutrino problem
The image of the first solar neutrino detector by Scientific American

The attempts to detect in the 1960s only found 1/3 of the expected number based on the Sun’s energy output. This disagreement is called solar neutrino problem and solved in the early 2000s. Based on the solution, neutrinos come in three different types:

  1. Electron neutrinos
  2. Muon Neutrinos
  3. Tau Neutrinos

The problem that occurred in 1960s were because the early solar neutrino detectors could only detect electron neutrinos. Now, we know that neutrinos can change among the three types while passing through matter. In 1960s , the time solar neutrinos reach the detectors, only 1/3 are still electron neutrinos which resulted in the observation of only 1/3 of the expected number of neutrinos. In this modern era, we can be confident with this solution since the modern detectors can detect these types of neutrinos and confirmed that the number of solar neutrinos matches predictions. To learn more about neutrinos, there is a great link below here.