Looking at the night sky, it would appear that the stars represent the predominant type of objects in the cosmos. However, appearances are deceiving. According to current cosmology, the universe consists mainly of hard-to-understand dark energy – a substance whose essence still eludes correct conception – and a hidden substance that manifests itself only through gravity, but does not shine in any way. Only less than 5% of the mass and energy of the cosmos is made up of the known “normal” (technically baryonic) matter, and of this only about 10% is stored in stars. The vast majority of baryonic matter is found in the gas.
However, the stalagmites differ from each other in particular in terms of weight, which determines the majority of their properties – primarily development or chemical composition. In the universe we can find stars that are perhaps only 80 times more massive than Jupiter (so they reach about 7% of the mass of the Sun), but also those whose mass exceeds our star 100 times. In the past, even stars 500 times more massive than the Sun could have appeared.
Since we do not know the statistical distribution of stars according to their mass accurately enough to be representative of the entire universe, we can only estimate their total number. There are approximately 100 billion stars in the average galaxy, with about 10 trillion star islands in the universe. In total, there are probably a quadrillion (10²⁴) stars in the cosmosplus or minus some order – which is a really respectable amount.
Intangibility as a foundation
The theory of stellar interiors and stellar evolution, which forms the basis of astrophysics, exclusively included stars composed of baryonic matter. Astronomers refer to a star as an object that is in hydrostatic equilibrium (i.e. “round”) and at the same time produces energy internally through thermonuclear reactions for a significant part of its life.
Known physical principles, however, admit the existence of bodies in hydrostatic balance, whose essence is other than ordinary baryonic matter. Because they are mostly very massive objects, they are referred to as stars. In some cases, these could be late development stages of common stars. However, the existence of the mentioned objects is only hypothetical, not yet supported by clear observational evidence.
Quark stars: Like a giant nucleon
In the final stages of the development of very massive stars, neutron degeneration of matter occurs, when protons are transformed into neutrons, and the resulting object – neutron star – can achieve a high degree of gravitational contraction without the resistance of electrostatic action. The theory admits that neutrons could decay under pressure into elementary particles, quarks. Such an object would be even more compact than a neutron star; and if there were no other matter flowing from the surroundings that could stimulate the continuation of the collapse to a black hole, the star could remain in the stage of the so-called quark stars until the end of his life. In essence, it would become a macroscopic elementary particle – a nucleon.
An object bearing a label 3C58, a pulsar in the constellation Cassiopeia, is most likely a remnant of the 1181 supernova, but it may be much older. Anyway, it seems that cools significantly faster than would be consistent with standard neutron star theory. One possible explanation is that it is a quark star. Various scholarly works admit that two other known pulsars could theoretically be quark stars; and careful observations of four recent supernova explosions suggest that they formed a quark star. In any case, the evidence is quite circumstantial.
Electroweak Stars: Denser and Stranger
Quark stars are probably the least exotic of all the hypothetical stars. However, let us now focus on collapsing supernovae, i.e. the final stages of lone stars. According to some models, during the collapse, a state may occur when the body resists the gravitational force by the pressure of radiation, which is released during the so-called electroweak combustion. During the mentioned process, quarks are transformed into leptony (electrons, but mainly neutrinos) using the electroweak interaction. This creates photons of very hard radiation. Such a star would remain stable for a relatively short period of time, about 10 million years.
A model of the internal structure of an electroweak star. Its outer layers are apparently made of similar material to neutron stars. Stálice has a diameter of approximately 5 km. At its center is a nucleus the size of an apple, made up of a mixture of quarks changing into leptons. However, such a small core would be about two Earth masses.
Electroweak stars could form at the moment when the pressure of quark degeneracy inside the quark star cannot resist its own gravity. It follows that electroweak stars should have an even greater density than quark stars. Again, these are purely hypothetical objects that, unlike quark constants, have no promising candidates. However, the reason may lie in the selection effect and also in the short lifetime of electroweak constants.
Boson Stars: Black Holes?
Both quark and electroweak stars described above consist of fermions, i.e. from elementary particles with half-numerical spin. The Pauli exclusion principle applies to fermions, according to which no two fermions can be found in the same quantum state. Therefore, for example, it is not possible for all fermions to have a fundamental energy. We owe the existence of chemical richness to this property, because it is only because of this that electrons create complex electron shells around atoms. If the electron were a boson – a particle with integer spin that does not obey the exclusion principle – all electrons would attack the ground energy level and no structured electron shells would form. The chemical richness of this world would be tatam.
So what if macroscopic objects consisting of bosons existed in the universe? We would label them as boson stars and they would have to be very dense, because the Pauli exclusion principle is the essence of all degenerate forces that resist gravity. Therefore, for boson stars to exist at all, they would have to be formed by some group of bosons for which there is a repulsive force. Scientists are thinking about exotic bosonsfor example, about hypothetical ones axions, which some experts consider to be the key to understanding the nature of the hidden substance. However, unlike fermion stars, boson stars would have to form during the early stages of the universe’s evolution, shortly after the Big Bang; they certainly could not arise from the collapse of ordinary objects.
Very massive boson stars represent an elegant solution to the problem of black holes in the cores of galaxies, the formation of which could not be satisfactorily explained by standard methods. If boson stars from the earliest stages of the universe’s evolution, with masses of millions to billions of suns, were located in the regions of the galactic centers instead, there would be no need to deal with the problem of the formation of black holes at all. Unobservable boson stars of smaller masses would also nicely solve the missing hidden matter.
Preon Stars: Beyond Current Physics
Some scientists do not let the current state of knowledge hold them back and go even further in the construction of exotic objects. They believe, for example, that just as the atomic nucleus is made up of protons and neutrons, which are further made up of quarks, quarks (or leptons) cannot be considered truly elementary particles either: They consist of even smaller constituents – preons. However, despite immeasurable efforts, they could not be detected on the accelerators, and there are no indications of their existence from the experiments being carried out. If preons were real, nothing would probably prevent the theoretical construction of a preon star. Theorists expect such objects to be truly superdense, with values of around 10²³ kg/m³, which exceeds neutron stars by about six orders of magnitude.
TIP: Hypothetical objects: 10+1 space objects that probably don’t exist
Preon stars could either represent remnants of the Big Bang or they could form in supernova explosions. The constructed theory does not require them to be extremely massive, so preon stars with only a tenth of the mass of the Sun could be stable for a long time. A preon star with a mass of 100 Earth equivalents would then have a dimension of around one meter. Even preon stars are a candidate for the essence of hidden matter. They would interact with the baryonic matter only gravitationally, and their mapping – if they exist – can therefore only be done indirectly.
A model of the universe
According to the standard model of particle physics, all known matter in the universe is made up of elementary particles, or fermions – six kinds of quarks and six kinds of leptons. Any known particle can be “assembled” using the standard model. Between the elementary particles there is a strong, weak and electromagnetic interaction, mediated by particles called bosons. The Higgs boson, which is responsible for mass, and the graviton, which is responsible for gravitational action, are on the side of the basic table.
2023-07-22 22:13:52
#Stills #Wonderland #stars #quarks #bosons #preons
