Questions tagged [neutron-stars]

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Neutrino emission rate of neutron stars?

I often hear that neutron stars emit 30-40% of their energy as neutrinos. But how many neutrinos do neutron stars emit per second ?
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Mass gap between neutron stars and black holes

From the detection of gravitational waves in GW190814, the merging of a 2.6 solar mass compact object with a heavier object has been inferred. The lighter object is in the "mass gap" between ...
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Isolated Neutron Stars

What is the difference between isolated neutron stars and neutron stars ? What is the meaning of isolated here ?
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Pauli exclusion principle and quantum state

Wikipedia says that two identical fermions cannot occupy the same quantum state. My question is what this quantum state means? In classical mechanics, this means that the two particles cannot have the ...
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What generates a neutron star's magnetic field?

Is the magnetic field of a neutron star generated by the minuscule amount of protons and electrons left or the spin of the neutrons? If its because of the spin of the neutrons, how come they are all ...
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Rotating neutron star: gravitational field oblong factor

In a neutron star which is rotating at relativistic speed (say along z axis), the gravitational field is oblong in the x and y axis. Is there a simple equation that let us calculate the oblong factor ...
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Under what conditions would neutrons pair up to produce bosons in the core of neutron star to form Bose-Einstein Condensates?

In Neutron star, the fermions get converted to bosons and form Bose-Einstein Condensates in its core. I couldn't find under what specific condition this phenomena takes place.
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How far the gravitational waves can travel?

How far the gravitational waves can travel? Does it depend on the mass which is converted to energy in a black hole/neutron star merger? If there is a finite distance, were we lucky to be in the range ...
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1answer
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Uncertainty in estimation of mass neutron star

Can somebody explain why there is a large uncertainty in the mass estimation of neutron stars?
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Is a neutron star more 'fluid' than a quark star?

Intuitively, I would say quark stars are less 'fluid', because they have a greater gravitational force pulling the star together. Is it true that a neutron star is more 'fluid' than a quark star? If ...
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How do tidal forces change gravitational waves

If there is a binary of two neutron stars, they are going to be deformed because of the tidal forces. I suppose that it will cause a change in the movement of the stars and that will cause a change in ...
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1answer
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Can you detect gravitational waves emitted by quark stars?

Quark stars are a bit like neutron stars, they have very large masses and small radii. Can we detect gravitational waves emitted in a binary of two quark stars or the gravitational waves from a not ...
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1answer
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Are there any black hole neutron star binary?

Has a black hole-neutron star binary aver been observed? I mean observed in any way: gravitationally, through eclipse, or any other means. EDIT Thanks to the comment to this question, we know that ...
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1answer
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Was ever observed a black hole - neutron star merger?

I remember that a few months ago the news of a possible a black hole-neutron star merger detected with LIGO/VIRGO was diffused. Was this discovery confirmed?
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Can Zeeman effect occurs in gravitational wave from binary blackhole-magnetar merger

I understand that Zeeman effect is behind the splitting of spectrum lines in an atom in strong magnetic field, I was wondering if such phenomenon could occur outside electromagnetic wave such as from ...
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Fast rotating black holes converting into neutron stars

I know that there are some researchs about neutron star slower their spinning they can transform into black holes. Is there any research about the reverse process? Going from a black hole of 1 $M_{\...
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Black Hole Mass Density Ratio [duplicate]

(1) The density of water increases as one approaches the bottom of the sea. (2) The density of neutron stars also increases from crust to core. Black holes with greater mass have a larger radius and ...
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1answer
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What is the difference between the rot_star and nrotstar class in LORENE (Numerical Relativity)

Im doing my final grade work about neutron stars simulations. I need to compute some simulations for different EoS. In the classes, I find two different classes: nrotstar-> I think the n means ...
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Could 2 collided neutron stars partialy lose mass?

If two collided black holes lose a huge part of their masses before collision do a pair of neutron stars lose such quantity of mass and is the density of an astronomical body the cause of how much of ...
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Why do neutron stars have such powerful magnetic fields?

The magnetic strength of these objects is too low based on flux conservation from the original star and yet too high for a composition of mainly neutrons. Is it actually due to some quantum effect?
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What are the physical properties of momentum space?

In classical mechanics, the phase space is the space of all possible states of a physical system; by “state” we do not simply mean the positions q of all the objects in the system (which would occupy ...
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Can small amounts of neutron star matter or similar neutron-degenerate matter be (briefly) produced by radiation implosion or similar methods?

Today, a variety of methods are used to implode pellets of fusion fuel in order to perform inertial-confinement fusion. The pellets explode apart in microseconds whether or not fusion actually happens,...
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Free decompression of white dwarf or neutron star matter — what do we end up with?

(Possibly related: What would happen to a teaspoon of neutron star material if released on Earth?) Suppose that we somehow produced or obtained a small amount of neutron star matter or white dwarf ...
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Is a neutron star a classical system or a quantum one?

If we consider the perspective that the neutron star is just a very large atom, then theoretically (disregarding that the smallest possible neutron star is kilometers in diameter) from the hydrogen ...
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Can Ligo tell a blackhole and neutron star of same mass throughout the inspiral? [duplicate]

I am wondering what if a massive blackhole which is say thrice as massive as our Sun is gobbling up a neutron star also happens to be of the exact same mass, so in this scenario can Ligo be able to ...
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Is it possible that galaxies formed from incredibly fast neutron star collisions?

In the recent Kurzgesagt youtube video there is mention of how neutron star collisions are the likely candidates for creating the heavier elements in the universe. It is also possible that it created ...
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2answers
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Is the remnant of the Solar System's “parent” star still drifting in outer space?

As all elements which are heavier than iron, are only created through the process of either a supernova or a kilonova explosion. With us having naturally occurring elements such as uranium on Earth it ...
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How would a quark star maintain degeneracy near the surface?

I'm still not exactly understanding how a quark star could possibly exist for more than a fraction of a second. Neutron stars are already hypothesized to have degenerate quark matter at their cores, ...
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1answer
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Microscopic process of electron degeneracy pressure

When a star becomes a neutron star, it says that the gravity is so large that it exceed the electron degeneracy pressure then electron combine with atomic nucleus to give neutrons. Is there known/...
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Why do Type II supernova happen? [duplicate]

I am an engineer and not a physicist. I am unable to understand why SuperNova happen. I understand that when the core is composed of high atomic number of elements like Iron and further fusion is not ...
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2answers
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Are neutron star cores thought to be stiffer than photon gases?

The weak energy condition and with the dominant energy condition allow anything from w=-1 to 1 (meaning that the magnitude of the pressure can be at most equal to the total mass-energy density). ...
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1answer
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Artificial degenerate matter (by “non-explodey” methods) — physically plausible?

White dwarf matter, neutron-degenerate matter (I'm still confused as to whether this is the same thing as "neutronium" or not), and other possible types of degenerate matter like quark stars are ...
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How do neutron star binaries form?

Do neutron star binary systems come from previously active-star binaries, where where both stars have gone supernova and left behind neutron stars that are still in orbit? Or do they form when two ...
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What's the shortest “safe” distance from a neutron star merger?

Take GW170817 for example, the first neutron star collision picked up by LIGO. Given how much data we got from that event, can anyone figure out what the "blast radius" is, and how far away from the ...
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Can Thorne–Żytkow object (heavenly body) exist in universe?

Can Thorne–Żytkow object (heavenly body) exist in universe? It's a new concept I came across. Are there such heavenly bodies in universe? It's a heavenly body in which a neutron star is present inside ...
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Neutron star modelling with polytrope

I want to model the density profile of a neutron star with 1.4 $M_\odot$ with a polytrope $p=\kappa\rho^{\gamma}$ with $\gamma=1+\frac{1}{n}$. I started with $n=\frac{1}{2}$ and solved the Lane-Emden ...
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Percentage of Neutron Stars that leave the Galaxy

When a neutron star(NS) is born the supernova kick gives the newborn NS a certain boost in a supposed isotropic direction and, depending on how strong the boost is and on the position of the NS at ...
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Why were pulsars not discovered in the visual spectrum?

In 1967, the first pulsar was discovered at a radio observatory in Cambridge. Radio astronomy started around the 1930s, but astronomy in the visible part of the spectrum had been done for a long time ...
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Gravitational $N$-body mergers?

Beyond binary systems and its mergers, have numerical relativity groups computed an approximation to $N$-body GW signals/waveforms or is that a hard unsolved task?
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How do LIGO and Virgo know that a gravitational wave has its origin in a neutron star or a black hole?

It is being said that gravitational-wave detectors are now able to distinguish neutron star waves from those originating from black holes. Two Questions: How do LIGO and Virgo know that a ...
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How does a Thorne Zytkow star die?

A Thorne-Zytkow star is one where a red giant or supergiant contains a neutron star at its core, formed from the collision of the giant with the neutron star. It is believed that one has been found in ...
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Doubt about the Einstein Field Equations (EFE) of a Magnetar

The Schwarzschild solution could be an good model for a planet and a star, without rotation and electric and magnetic charge. Besides the fact that this solution is spherically symmetric. The metric ...
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Strange quarks in neutron stars

Recently I have read that the pressure within neutron stars can be so extreme that it can cause the deconfinement of quarks to form a kind of quark 'soup' and that these extreme conditions allow for ...
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What is inside a black hole? [duplicate]

I'm trying to understand what causes a black hole in terms of it's composition. We know a start can die and collapse into a neutron star, but if the neutro star is not dense enough to create a black ...
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Do different neutron stars have different density?

When stars go supernova, a neutron star may be left over if there isn't enough mass to create a black hole. Based on the mass present, will a neutron star have a varying density or is the radius ...
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Is there a relatively painless way to calculate the radius of a neutron star, given its mass?

I know there are different models based on, as I understand it, different equations of state describing the neutron star mass-raduis relation. I'm not sure what to do with that, though. My math isn't ...
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Where do gravitational waves draw the energy from?

Imagine binary neutron stars inspiral, they generate gravitational wave which carries energy away and causing the pair to become ever closer. Since all wave must carry energy I wonder where do ...
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Gravitational waves and chirp waveform

When two neutron stars collide emitting gravitational waves, what exactly does the chirp waveform represent and how is it used to infer the distance to the source?
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Why do neutron stars with more mass have smaller volume?

I know about Heisenberg uncertainty which makes more localized neutrons have a wider range of undefined momentum, and Pauli exclusion principle which prohibit neutrons from getting too close or "...
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What is the closest distance for an undiscovered old neutron star and how long would it take to get here? To help people scared of neutron stars

This is to help people who are scared of neutron stars. My questions are What is the faintest a neutron star could be How close could it be and not yet be detected How long would it take to get here ...

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