The universe may contain extremely dense and exotic hypothetical cosmic objects known as exotic quark stars. As astrophysicists continue to debate the existence of quark stars, a team of physicists has found that the remnants of a neutron star merger observed in 2019 have just the right mass to be one of these exotic quark stars.
When the stars dieTheir cores are compressed to such incredible degrees that they become entirely new kinds of things. for example, When the sun finally flasheswill leave behind a white dwarf, a planet-sized ball of highly pressurized carbon and oxygen atoms. When even the largest stars explode in a catastrophe called eruptions supernovae, leaving behind neutron stars. These incredibly dense objects are only a few miles wide but can weigh a few times the mass of the Sun. As its name suggests, it is made almost entirely of pure neutrons, essentially making it atomic nuclei kilometers wide.
neutron stars So strange that physicists don’t yet fully understand it. While we can observe how neutron stars interact with their surroundings and make some good guesses about what happens to all that neutron matter near the surface, the composition of their nuclei remains elusive.
Related: Are quark stars possible?
The problem is that neutrons are not completely fundamental particles. Although they combine with protons to form atomic nuclei, neutrons themselves are made of smaller particles called quarks.
There are six types, or “flavors,” of quarks: up, down, up, down, strange and magic. A neutron is made of two down quarks and one up quark. If you crush a lot of atoms together, they come back into a giant ball of neutrons. So, if you squeeze a lot of neutrons together, does it come back into a giant ball of quarks?
The answers vary from “maybe” to “it’s complicated.” The problem is that quarks don’t really have unity. The strong nuclear power, which binds quarks in a nucleus, actually grows with distance. If you try to pull two quarks together, the force pulling them back increases. Eventually, the attractive energy between them becomes so great that new particles appear in the void, including new quarks that are more than happy to associate with the separated ones.
If you were to make a macroscopic body of up or down quarks that make up a neutron, that body would explode very quickly and very violently.
But there could be a path using strange quarks. By themselves, strange quarks are very heavy, and when left alone, they quickly decay into lighter up and down quarks. When large numbers of quarks cluster together, physics may change. Physicists have found that strange quarks can bind with up and down quarks to form triplets, known as “strangles,” which may be stable — but only under extreme pressures. Like pressures one step above a neutron star.
If you compress a neutron star too much, all the neutrons lose their ability to support the star, and everything collapses to make Black hole. But there may be a step trapped in between, where the pressures are high enough to melt neutrons and form a strange quark star but not intense enough gravity To take full control.
Astronomers don’t expect to find many strange stars in the universe. These objects should be heavier than neutron stars but lighter than black holes, and there’s not much room for maneuver there. Because we don’t fully understand the physics of the strangler, we don’t even know the exact masses in which exotic stars can be located.
But recently, a team of astronomers looked at GW190425, a gravitational wave event triggered by the merger of two neutron stars observed in 2019. Combined with massive amounts of gravitational waves, the merging neutron star results in a kilonova, which is a stronger explosion than an ordinary explosion. nova but weaker than a supernova. Although astronomers were unable to take a picture electromagnetic A clue from this event, they saw a similar event in 2017 that produced both gravitational waves and radiation.
When two neutron stars merge, there are a few options available depending on their mass, rotation, and angle of collision. According to theoretical calculations, neutron stars can erase each other, forming a black hole, or make a slightly larger neutron star.
According to the new research that was Recently published in the prepress database arXivthese cosmic collisions could make a strange quark star.
The team calculated that the body mass left by the 2019 merger was somewhere between 3.11 and 3.54 . solar masses. Based on our best understanding of the structure of neutron stars, this is a bit too heavy, and should collapse into a black hole. But they also fall within the mass range that models of the structures of these exotic stars allow.
It’s still too early to tell if GW190425 is our first observation of a rare alien quark star, but future observations (and more theoretical work) may help astronomers identify one of these strange creatures.