Illustration showing the life of a Sun-like-star starting from the main sequence (the hydrogen-burning phase). This is the longest-lived part of the life-cycle,around 10 billion years (1). Once the core hydrogen is depleted,the star begins to swells into a subgiant about two or three times its original size - cooler and more orange,yet brighter because of its greater surface area (2). For a few hundred million years,the star burns hydrogen in a narrow shell on the outskirts of the inert helium core. Once the shell hydrogen runs out,the star expands into a red giant,up to 200 times its main-sequence radius (not shown to scale,3). It then begins to shed its outermost layers in a series of pulsations (4),leading to the creation of a planetary nebula (not shown to scale,5). Finally,once this has dispersed after around 10,000 years,only the inert core remains - a white dwarf (6) | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Garlick, Mark |
Taille de l’image : | 4004 px × 5388 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |