The sun owes its brightness to the fusion. But what fusion?

2003/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Astrofisika

In the Sun, hydrogen atoms merge continuously to form helium. However, in some cases, the participation of carbon atoms is fundamental for this to occur.

(Photo: ANDÉN).

This type of fusion is called CNO cycle. Now, an international group of physicists has calculated the proportion of this process, with a maximum of 7% carbon presence in the reaction.

According to the Standard Solar Model, only 1.5% of the fusion energy is generated in the CNO cycle. But that is theory and it has never been proven because there have been no tools available. The researchers knew that the key could be in neutrinos, since the energy of neutrinos produced in one or another fusion reaction is different. However, current detectors are not able to perform this measurement with precision and also:

Some neutrinos that leave the Sun transform into the Earth. For this reason, at the moment they have only made a maximum estimate. They say that if a completely new methodology is not developed, the theoretical prediction cannot be verified.