pelkistymisvaiheessa
Pelkistymisvaiheessa refers to a stage in the life cycle of a star, specifically a red giant or supergiant, where the star is undergoing significant changes in its internal structure and energy production. This phase is characterized by the star's outer layers expanding and cooling, causing it to become much larger and brighter than it was in its previous stage. The core of the star, however, is contracting and heating up, leading to increased nuclear fusion rates.
During the pelkistymisvaiheessa, the star's outer layers can extend to hundreds or even thousands of times
The pelkistymisvaiheessa is a relatively short stage in a star's life, lasting only a few million years