Dark star (dark matter)
Encyclopedia
A dark star is a theoretical type of star that may have existed early in the history of the universe before conventional stars were able to form. They would be composed mostly of normal matter, like modern stars, but a high concentration of neutralino
dark matter
within them would generate heat via annihilation
reactions between the dark-matter particles. This heat would prevent such stars from collapsing into the relatively compact sizes of modern stars and therefore prevent nuclear fusion among the normal matter atoms from being initiated.
Under this model, a dark star is predicted to be an enormous cloud of hydrogen and helium ranging between 4 and 2000 astronomical unit
s in diameter and with a surface temperature low enough that the emitted radiation would be invisible to the naked eye.
It is possible that dark stars have endured to the modern era. Although they would emit no visible light they could be detectable by their emissions of gamma ray
s, neutrino
s, and antimatter
and would be associated with clouds of cold molecular hydrogen gas that normally wouldn’t harbor such energetic particles.
Neutralino
In particle physics, the neutralino is a hypothetical particle predicted by supersymmetry. There are four neutralinos that are fermions and are electrically neutral, the lightest of which is typically stable...
dark matter
Dark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...
within them would generate heat via annihilation
Annihilation
Annihilation is defined as "total destruction" or "complete obliteration" of an object; having its root in the Latin nihil . A literal translation is "to make into nothing"....
reactions between the dark-matter particles. This heat would prevent such stars from collapsing into the relatively compact sizes of modern stars and therefore prevent nuclear fusion among the normal matter atoms from being initiated.
Under this model, a dark star is predicted to be an enormous cloud of hydrogen and helium ranging between 4 and 2000 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s in diameter and with a surface temperature low enough that the emitted radiation would be invisible to the naked eye.
It is possible that dark stars have endured to the modern era. Although they would emit no visible light they could be detectable by their emissions of gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
s, neutrino
Neutrino
A neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...
s, and antimatter
Antimatter
In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles...
and would be associated with clouds of cold molecular hydrogen gas that normally wouldn’t harbor such energetic particles.