A dark star is a hypothetical type of

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

that may have existed early in the

universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. Acc ...

before conventional stars were able to form and thrive.

Properties

The dark stars would be composed mostly of normal

matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic partic ...

, like modern stars, but a high concentration of

neutralino In supersymmetry, the neutralino is a hypothetical particle. In the Minimal Supersymmetric Standard Model (MSSM), a popular model of realization of supersymmetry at a low energy, there are four neutralinos that are fermions and are electrically ...

dark matter Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not ab ...

present 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 and dense sizes of modern stars and therefore prevent

nuclear fusion Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manifest ...

among the 'normal' matter

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, and ...

s from being initiated. Under this model, a dark star is predicted to be an enormous cloud of molecular hydrogen and helium ranging between 1 and 960

astronomical unit The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...

s (AU) in radius and with a surface temperature and

luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...

low enough that the emitted radiation would be invisible to the naked eye. In the unlikely event that dark stars have endured to the modern era, they could be detectable by their emissions of

gamma ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...

s, and

antimatter In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter. Antimatter occurs in natural processes like cosmic ray collisions and some types of radioac ...

and would be associated with clouds of cold molecular hydrogen gas that normally would not harbor such energetic, extreme, and rare particles.

Possible dark star candidates

In April 2023, a study investigated four extremely

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

ed objects discovered by the

James Webb Space Telescope The James Webb Space Telescope (JWST) is a space telescope which conducts infrared astronomy. As the largest optical telescope in space, its high resolution and sensitivity allow it to view objects too old, distant, or faint for the Hubble Spa ...

. Their study suggested that all of them,

JADES-GS-z13-0 JADES-GS-z13-0 is a high-redshift Lyman-break galaxy discovered by the James Webb Space Telescope (JWST) during NIRCam imaging for the JWST Advanced Deep Extragalactic Survey (JADES) on 29 September 2022. Spectroscopic observations by JWST's NI ...

, JADES-GS-z12-0, and JADES-GS-z11-0, are consistent with being point sources, and further suggested that the only point sources which could exist in this time and be bright enough to be observed at these phenomenal distances and redshifts (z = 10-13) were supermassive dark stars in the

early universe The chronology of the universe describes the history and future of the universe according to Big Bang cosmology. Research published in 2015 estimates the earliest stages of the universe's existence as taking place 13.8 billion years ago, wit ...

, powered by dark matter annihilation. Their spectral analysis of the objects suggested that they were between 500,000 and 1 million

solar mass The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

es (), as well as having a luminosity of billions of

Suns Suns may refer to: * Gold Coast Suns, Australian rules football team * Phoenix Suns, basketball team *The Sun, the star of the solar system * Stars, massive balls of plasma * Sun (unit), or cun, a traditional Chinese unit of length *An abbreviatio ...

(); they would also likely be huge, possibly with radii surpassing 10,000

solar radii Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\tim ...

(), far exceeding the size of the largest modern stars.

References

External links

* * * * * * * {{Black holes Star types

Star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

Dark concepts in astrophysics Hypothetical stars Black holes

Properties

Possible dark star candidates

See also

References

Further reading

External links