Humans have facinated by the stars since ancient times. Stars plays a key role in the development of humanity. Humans are very curious about stars since ancient times. Due to the help of modern science we know much about the stars and still our knowledge on this topic is developing and cosmologist have proposed a wide variety of theoretical stars that may exit in space. In nutshell, "the theoretical stars are those stars which have all star like structure but different in the chemical composition and fusion energy sources"
Since science is mostly based on assumption or anything we can't find or describe, we present theories. Do, in this topic I am providing you some lists of theoretical stars that may or may not exists.
10.Quark Star:
At the end of life, a star can collapse into a black hole, a white or red dwarfs or a neutron star. If the density of the star is sufficient enough before eruption into a supernova then the stellar remnant would form a neutron star. When the star transforms into super nova it becomes extremely hot and dense. Do to the so much energy the star began to collapse on itself and forms a singularity, but due to the fermions particles in the centre obey the Paul exclusion principle. Which ears that the neutrons stars cannot be compressed into same quantum state, so they push back again st the collapsing matter and reaches in equilibrium state.
Many astronomers believe that neutron stars are cannot be compressed further, but due to the development in quantum theory astrophysicists proposed a new type of star that would occur when the degenerative pressure of the neutron core failed. This star is called a "quark star".
In quark star, as the pressure of the star mass increases, the neutrons in the core of a neutron star breaks up into their constituent up and down quarks, which can exit freely under intense pressure and energy. This quark very dense and is also known "strange matter",
Formation of these stars are still a mystery. Some theories states that they occur when the mass of a collapsing star is between the necessary mass to form a black hole or a neutron star. Another theory states that when dense packets of preexisting "strange matter" is bounded around "weakly interacting massive particles (WIMPs)", collide with a neutron star, it seeded it's core with "strange matter" and started to doing a quark star. If this happens then the crust of this star would be of neutron star while the core will be made up of "strange matter". Although no any quark star have been sighted in our universe.
9.Electroweak Stars:
The astrophysicists have recently proposed a new type of star called "electroweak star". According to astrophysicists when a star is about to transform into quark star to black hole "electroweak star" is formed. It is able to sustain the equilibrium due to its interaction between weak nuclear force and electromagnetic for collectively known as electro-weak force.
The pressure and energy from the mass in " electroweak stars" pushes it down on quark's star core. As the energy increases further, the electromagnetic and weak nuclear forces got mix and no distinction left between these two forces. Due to this huge energy level the quark's core get converted into leptons (electrons and neutrinos). Most of the strange matter is converted into leptons and the released energy provide an outward force that is enough to stop stellar collapse.
Scientists are instreasted in finding such stars because their core shows the characterstics of early universe, when there was no distinction between electromagnetic and nuclear forces.
Electroweak stars are one of the dense object in our universe. Since if the core of an electroweak star is the size of an apple then it would contain a ads equals to two earths.
8.Throne Zytkow Object (TZO):
In 1977, two astrophysicists Kip throne and Anna Zytkow published a paper containing the details of a new type of star called Throne-Zytkow Objects (TZO) .
This type of star is formed when a neutron star collides with a red supergiant. It is also called a hybrid star. Due to the large size of red supergiant star, it takes a hundred of years for a neutron star to breach the inner atmosphere of a red supergiant star. As neutron star continues to burrow into the star their orbital centre will move towards the centre of red supergiant. After a time these two stars will merge into each other causing a supernovae and eventually a black hole.
When you see TZO, it will looks like atypical red supergiant only the chic composition will be different. The burrowing neutron stars causes the radio wave bursts from inside. It is very difficult to find a TZO since they somehow looks like a red supergiants and also they may form near the centre of our galaxy where the population of the stars is high and probability of collision is also high.
In 2014, astronomers found a star named HV2112,which was the possibility le candidate of TZO. Researchers have found that it contains high amount of metallic elements making it a possible candidate TZO.
7.Frozen Star:
A normal star fuses hydrogen to form helium and support itself with the outward pressure. However, a time come when there is no hydrogen left in the star's core and it began to fuse helium and other heavier elements. The energy released in this process is not sufficient and a star begins to cool. When star burst into supernovae, it spread it's metallic elements that plays a major role in the formation of new stars and planets.
Scientists have hypothesised that as universe grew older, the more stats will explode and metallic contents will increase in the universe. In future the stars would have very large amount of metallic elements in them. So as the universe ages further, a new type of metallic stars will form, including the hypothetical frozen stars.
This type of stars was proposed in 1990s. With the abundance of metallic elements in the universe , the newly forming stars would need very low temperature to become a main sequence star. The stars with 0.04 stellar masses (size of jupiter), could become a main sequence star and can sustain nuclear fusion only at 0°C (32°F). They would be frozen and surround by the clouds of ice.
6.Magnetospheric Eternally Collapsing Objects (MECO):
The black hole's are the most mysterious and odd objects in the outer space. There are many theories and paradoxes about black holes. To deal with these problems the scientists have proposed a variety of different stars like objects. In 2003, the scientists proposed a theory about black holes, in which they called that, "the black holes are not actually singularities, but are an exotic type of starts called the "Magnetospheric Externally Collapsing Objects (MECO)". This model have been made to deal with the theoretical problems regarding the matter of collaping black holes travels faster than the speed of light.
Formation of a MECO is just like the black holes. However, in MECO the tradition due to the colliding subatomic particles produces an outward pressure caused by fusion in the star's core. This makes a MECO stable. Due to this it never forks an event horizon and never completely collapse. Black holes collapse and evaporate die to the hawking radiation whereas a MECO would take infinite time to collapse and evaporate. This it enters in the state of eternal collapsing.
MECO theory solved many problems regarding to black hole. Since a MECO bender collapse so it does not have the problems of destruction like black hole.
5.Population 3 Star:
After the Big bang when there were primordial gas left a new type of starts were formed known as "population 3 stars". According to the start population scheme "the higher the population, the higher the metal content". There are mainly two population of stars namely, population 1 & population 2. But now astrophysicists have gotten serious on the search of stars that must had existed after the Big bang. These stats are known as "population 3 stars".
These stars were extremely short lived, about two million years. These stars burn their hydrogen fuel quickly & began to fuse heavy elements in their core and exploded. Scattering their heavier elements all over the universe.
Astronomers believe that these stars will allow us to know the better understanding of our early universe. Since, the according to astrophysics "if you are looking at a light beam
coming from a light scource that is billions of light year away from us then you are actually looking back in time about millions of years, because time taken by the light beam to reach you is millions of years". So thats why the study of these farthest stars and galaxies would provide a lots of information about the early universe.
4.Quasi stars:
The quasi star is a theoritical star that may exists in the early stages of our universe. They would be a cannibal star, but instead of having another in the middle of it, it would have a black hole. It would formed from massive population 3 stars.
After the collapsing of a normal star, they go supernova & leave a black hole but in a quasi star, its massive and dense outer layer of nuclear would absorb the energy blast of the collapsing core and stayed in place without going to supernova blast. The outer shell would remain intact, while a black hole is formed inside a quasi star. The energy released by the black hole core is enough to resists the gravitional collapse. A quasi star would fed by the materials falling into the internal black hole. Because of the massive release of the energy a quasi star would be a extremely bright and massive stars in the early universe about 7,000 times more massive than our sun.
A quasi star would have been lose its outer shell after a million years, leaving only a massive black hole. Astrophysicists have theorised that super massive black holes that lie in the centre of the most of the galaxies, are formed due to these quasi stars.
3.Peron stars:
Many philosophers from ancient times thought that what is the smallest division of the matter is possible. With the discovery of proton, electron and neutron they thought that they had found the smallest possible division of the matter. But in the discovery of science , later there were many smallest of the smallest particles have been discovered like highs boson, neutrinos, quark's, etc. Lets leave this topic it would go forever.
Some scientist have proposed the "peron", a smallest particle which has no dimensions". It could be the most basic sub atomic particles.
So in this case a star made up of peron particles is called a "peron star". Thi's star will be extremely tiny star ranging the size of a pea and a football. Packed in such a small tiny area it's mass would be equal to the mass of our moon. It would be much denser object in the universe roughly denser that thar of neutron star. These little stars will be hard to see and would only visible under the gravitional lensing and gamma ray radiation. Due to its undetectable nature they may be the possible candidates for dark matter.
2.Planck star:
A black hole always confuses the scientists. We don't know what is inside a black hole. Many theories, books, sci-fi movies have been made based on the black hole. But more often, scientists have theorised that the centre of a black hole consists of a sigularity with infinite density density and no spatial dimension. However, a new theory states that, the centre of a black actually consists a star called "planck star"
A plank star is a strange star in which a normal nuclear fusion is occurred but the star would have energy near the "planck density". Energy density is the measure of energy in a region of space and planck density is the largest possible energy present in a region of space that is "5. 15×10*96 kilogram per cubic meter. Theoritically, this much of energy was present in the early universe.
1.Fuzball:
"Fuzzball" theory comes from strung theory, when astrophysicists attempts to describe a black hole on the basis of string theory. As such a "fuzzball" is not a star but a region of entangled energy strings which are supported by their own internal energy.
Since Since there are many mystries surrounding a black hole's centre. The fuzzball theory seems to solve these concerns. To understand what is fuzzball? Lets assume ourselves living inside a two - dimensional world like a piece of paper. If someone puts a cylinder onto the paper we would p receive as a 2D circle, even though the object actually exists in 3D. So from this we can imagine that higher dimensional parameters exists in our universe according to string theory. These dimensions are called "branes". So if a higher dimensional structures branes existed, we can only p receive it with our 3D senses. String theorists have proposed that a black hole is just a lower dimensional preception of higher dimensional string structure that is intersecting with our 3D space time. Thus, a black hole is not really a singularity, it is just the intersection of our space - time with higher dimensional strings and this intersection is called a "Fuzzball". So if the black holes are fuzzball then they can solve many controversies regarding a black hole. It also have some different charactersticts than black holes like instead of 1D singularity they have a definite volume but no precise event horizon.
No comments:
Post a Comment