hydrogen/burning in neutron star atmospheresAn analysis is presented of the burning and diffusion of hydrogen and helium in a neutron-star atmosphere. An initial two-component atmosphere of hydrogen and carbon and of helium and carbon is examined utilizing various photospheric temperatures. The ...
While normal stars have surfaces composed of hydrogen and helium, the stars discovered by Werner and his colleagues have their surfaces covered with carbon and oxygen, the ashes of helium burning – an exotic composition for a star. The situation becomes more puzzling as the new stars have ...
Such a system provides a key clue in mapping the binary evolution scheme from the second common envelope ejection to the formation of AM CVn stars having a helium-star donor. It may also serve as a crucial verification binary of space-borne GW observatories such as LISA and TianQin in the ...
We study the sensitivity of presupernova evolution and supernova nucleosynthesis yields of massive stars to variations of the helium-burning reaction rates within the range of their uncertainties. We use the current solar abundances from Lodders (2009) for the initial stellar composition. We compute...
1. Hydrogen-burning phase Every second the Sun converts 600 million tonnes of hydrogen into four million tonnes of energy: the rest is converted into helium ‘ash’. Throughout its life the Sun’s energy output has continued to increase, and it is thought to have grown 30 per cent brighte...
Though Population I stars consist mostly of hydrogen and helium gas, they also contain heavy elements (heavier than helium), which comprise about 1 or 2 percent of their mass. These heavier materials are fused from the lighter elements that the stars have collected. Thus, Population I stars ...
The evolution of massive stars through hydrogen and helium burning is addressed. A set of stellar evolutionary sequences for mass/solar mass of 15, 20, and 25, and metallicity of 0.002, 0.005, 0.007, 0.010, and 0.20 are presented; semiconvection is restricted to operating slower than the loc...
Two neutron star envelope models are chosen: one for which the hydrogen burning rate equals the accretion rate, and one for which the accretion rate equals the critical rate for which a combined hydrogen-helium shell flash is expected. Numerical results of the evolutionary sequences for each ...
This hot gas is constantly undergoing nuclear fusion, which is basically a fancy way of saying hydrogen atoms are smashing together to create helium and releasing a ton of energy in the process. This energy is what makes the Sun shine and heat up our planet. It's a prett...
Formed when the cosmos was filled with hydrogen and helium gases, they initially contained virtually no heavy elements. They shine until their fusible material is exhausted. When Population II stars die, their material is spread out into space. Some of this dust is eventually incorporated into ...