Astronomers have been able to obtain the first image of such a disc, providing direct evidence that. If the star is massive enough, the neutron star will collapse further and form a black hole. Dusty disc closely encircling a massive baby star. In the centre of the debris from the explosion is an incredibly dense neutron star. The core therefore collapses and releases a huge amount of energy in an explosion called a supernova. In low mass stars, once helium fusion has occurred, the core will never get hot or dense enough to fuse any additional elements, so the star begins to die. Once silicon has fused into iron, no more fusion occurs, as the fusion of iron requires more energy than it releases. For example, in a 25 solar mass star, hydrogen burning would take about 7 × 10 6 years, helium burning 7 × 10 5 years, carbon burning 600 years, neon burning 1 year, oxygen burning 6 months and silicon burning one day. Each stage of burning lasts a shorter time than the previous one. Stage 1 - Massive stars evolve in a simlar way to a small stars until it reaces its main sequence stage (see small stars, stages 1-4). Then unlike low mass stars, they have enough mass that gravity contracts the core raising the temperature and carbon can fuse into neon, then neon into oxygen, then oxygen into silicon, then iron. This role remains important in the present day, most especially for rare, high-mass stars, where binary systems continue to provide critical insights into star. Here’s a list of the most massive known stars: HD 269810 (150 solar masses) Peony Nebula Star (150 solar masses) Eta Carinae (150 solar masses) Pistol Star (150 solar masses) LBV 1806-20 (130. After the hydrogen is exhausted, like low mass stars, a helium core with a hydrogen shell forms, then a carbon core, with helium and hydrogen shells. They have a hydrogen fusion core, but much of the hydrogen fusion happens via the CNO cycle. High mass stars go through a similar process to low mass stars in the beginning, except that it all happens much faster.
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