The Helix Nebula is a spectacular planetary nebula, created by a dying solar-type star. In several billion years, even our Sun, after ascending the asymptotic giant branch, could produce a nebula similar to this one, ionizing with its ultraviolet radiation the material expelled at the end of the AGB phase [NASA, NOAO, ESA, the Hubble Helix Nebula Team, M. Meixner, T.A. Rector]

The Fate of the Sun

The Sun is on the main sequence, the most prolonged and most stable phase of a star’s life, marked by the fusion of hydrogen in the stellar core. But what will happen to our star after the main sequence? It will face a long and complicated series of transformations, some of which will probably be catastrophic for the final destiny of the Earth. These transformations will be determined by events that will occur in the depth of the star, invisible to the view, but which have nevertheless been reconstructed with high precision in theoretical models. This article summarizes the main lines of the evolutionary history of a star with a mass equal to that of the Sun after the end of the main sequence

The stable phase of the life of a star with a mass equal to that of the Sun [1] lasts about ten billion years. It is the so-called main sequence, in which the hydrogen present in the core is gradually converted into helium. The nuclear fusion that feeds the…