proton-proton chain reaction

This occurs in the core region of the star using the proton-proton chain reaction process.

The first one, the proton-proton chain reaction, is the dominant energy source in stars with masses up to about the mass of the Sun.

Though the main reactions don't involve neutrinos, the side reactions such as the proton-proton chain reaction do.

Older stars start to accumulate helium produced by the proton-proton chain reaction and the carbon-nitrogen-oxygen cycle in their cores.

In the Sun, with a 10-million-kelvin core, hydrogen fuses to form helium in the proton-proton chain reaction:

In the cores of lower mass main sequence stars such as the Sun, the dominant process is the proton-proton chain reaction (pp-chain reaction).

The first step of the proton-proton chain reaction is a two-stage process; first, two protons fuse to form a diproton:

The proton-proton chain reaction is one of several fusion reactions by which stars convert hydrogen to helium, the primary alternative being the CNO cycle.

In most stars the fuel is provided by hydrogen, which can combine together to form helium through the proton-proton chain reaction or by the CNO cycle.

In stars, it is formed by the nuclear fusion of hydrogen in proton-proton chain reactions and the CNO cycle, part of stellar nucleosynthesis.

The Sun is a natural nuclear fusion reactor, powered by a proton-proton chain reaction which converts four hydrogen nuclei (protons) into helium, neutrinos, positrons and energy.

This reaction was also able to detect neutrinos from the initial proton fusion reaction of the proton-proton chain reaction, with an upper energy limit of 420 keV.

For a K-type main-sequence star, this fusion is dominated by the proton-proton chain reaction, wherein a series of mergers of four hydrogen nuclei results in a helium nucleus.

For a more massive protostar, the core temperature will eventually reach 10 million kelvin, initiating the proton-proton chain reaction and allowing hydrogen to fuse, first to deuterium and then to helium.

This process requires a temperature of about 15 million K, which is higher than the core temperature of the Sun, but is more efficient than the Sun's proton-proton chain reaction fusion reaction.

It occurs as the second stage of the proton-proton chain reaction, in which a deuterium nucleus formed from two protons fuses with a further proton, but can also proceed from primordial deuterium.

At an estimated 9% of the Sun's mass, Wolf 359 is just above the lowest limit at which a star can perform hydrogen fusion through the proton-proton chain reaction: 8% of the Sun's mass.

The protons produced by the second reaction can take part in the proton-proton chain reaction, or the CNO cycle, but they can also be captured by Na-23 to form Ne-20 plus a He-4 nucleus.

The Sudbury Neutrino Observatory is most sensitive to solar neutrinos produced by B. The detectors that use gallium are most sensitive to the solar neutrinos produced by the proton-proton chain reaction process.

The next year, Bethe showed that this process is a key link in the proton-proton chain reaction and the CNO cycle, which are the major ways that nuclear energy is released in the solar core and in massive stars.

Red dwarfs have sufficient hydrogen mass to sustain hydrogen fusion to helium via the proton-proton chain reaction, but do not have sufficient mass to create the temperatures and pressures necessary to fuse helium to carbon, nitrogen or oxygen (see CNO cycle).