Neutron star Definition and 174 Threads

Although it is definitely not simple, there are many reasons to consider that baryon number can be violated, for example: - while baryogenesis there was created more matter than antimatter, - hypothetical Hawking radiation can finally turn any matter (mainly baryons) into massless radiation...

If a neutron star can be seen dense enough in some inertial frames of reference (due to relativistic length contraction) to form a Black-Hole, but not in others, how could the two realities coexist? Thank you in advance.

Hello everyone. I'm looking for an good equation of state for a neutron star, I'm starting with a degenerate neutron gas, but i have nothing to compare my results, I've search on the internet for it but haven't success. May you guys could have any graph of it to help me ? Thanks a lot.

Since gravity is stronger the closer you get to center mass, is it possible some neutron stars have a black hole inside?

Hello to all. I've been trying to plot some graphs on Mathematica but I have faced some troubles so far. I am working on this paper by Lattimer on binary systems: https://arxiv.org/abs/astro-ph/0002203 I am trying to reproduce Figure 11 but something seems to go wrong. Here's what I have...

Homework Statement I'm doing a question from a past paper, preparing for an upcoming exam. There is no solutions so I was wondering if my answer is correct for all parts. Take a star to be a uniform sphere with mass M_{i}=3.0 \times 10^{30} Kg and radius R_{i} = 7.0 \times 10^{8}m that...

I have heard that in neutron stars, the atoms do not repel nor do they attract. In a sense, could this mean that these atoms nucleuses could touch each other, or could the atoms touch in general?

[This thread was split from https://www.physicsforums.com/threads/a-light-wave-and-a-sound-wave-travelling-together.878450/#post-5518001 as it's an interesting topic in its own right] That's actually an important point, in the core of neutron stars, the speed of sound increases with the...

Hi there, I have a problem to solve in Cosmology which says: "Write the formulas for the quantum kinetic energy of neutrons, protons and electrons as well as the formula for the gravitational energy for a neutron star that is comprised of free neutrons, protons and electrons in a ratio of Nn ...

Homework Statement Homework Equations rotational kinetic energy = 0.5 I ⋅ M ⋅ ω², where I is the moment of intertia, M the mass and ω the angular speed The Attempt at a Solution T = period of revolution K = kinetic energy associated with rotational moviment Since T increases with time...

Does the pressure within a neutron star compress the neutrons to a smaller size?

So a programme that I watched on tv was talking about neutron stars and they said that the neutron stars neutrons were formed by protons and electrons combining to make neutrons. I was just wondering, how does this work, in the field of the quarks in the proton and how they are effected by an...

The Equivalence Principle says depicting gravity as a field associated with matter is equivalent to picturing it as twisting of space. Is there a space-twisting equivalent of a collapsed star as a shell of condensed matter with interior of intense gravitational field energy (found in the field...

How durable are the neutron stars, ie how long can they last? Will they "evaporate" like black holes or something else will happen with them after a very long period of time (eons)? Or are they immortal? I'm asking because I have found nothing clear about the lifespan of a neutron star.

I am reading about mergers of a neutron star with a black hole and the association with GRB. While talking about the accretion disk, the paper I am reading says about the last stable circular orbit. Firstly I thought it was where the Roche limit lies, where mass transfer or matter ejection from...

Now kindly pardon my ignorance but I hope one of you can explain to me how this can be possible. A rotating neutron star or pulsar have been observed to spin at between 10 to 700 times per second. Now before I proceed further I like to draw your memories back to the merry go round we played as...

Hi everyone, The charged particles in the magnetic field around the neuton star, is accelerated along the magnetic field lines, which would go in a curve, from the north pole to the south pole. Due to the acceleration the particles will emit radiation, along their movement axis, and because the...

Does this neutron star have an accretion disk?: https://en.wikipedia.org/wiki/IGR_J11014-6103#/media/File:Lighthouse_nebula.jpg

Could neutron star jets with velocity greater than 0.9c be caused by a mix of ultra-relativistic core material escaping the star? See this link: http://www.dailygalaxy.com/my_weblog/2015/08/neutron-star-jets-near-speed-of-light-rival-those-of-black-holes.html

Is there any good information about the chemical composition of relativistic jets from neutron stars? If the chemical composition of the jets was different from the accretion material it could shed light on the process that forms the jets.

OK so some stars evolve into neutron stars which I assume are so small (10's of kms) because ALL empty space is removed between the atoms.. absolute highest density possible? Now.. is a black hole larger (massive and in diameter) than a neutron star and called a black hole only because the...

When a large amount of plasma radiates greatly while accreting on a magnetized neutron star, where does the radiation ultimately get its energy from, the magnetic field and/or gravitational field? Without doing the numbers, if the magnetic field does the work against the gravitational field, and...

If a bubble of quark type matter formed near the core of a magnetized neutron star, what would happen to its shape? Would it elongate along the magnetic field lines? Could it burst out of the magnetic poles of the star?

Hello all, I could be looking at this the wrong way but here it goes: From what I understand, if a star collapses into itself to form a neutron star, it would become more compact, denser and heavier with a larger gravitational attraction. Now, if I understand correctly, the size of...

In calculations of quantities in Neutron stars with degenerate matter is usual to set temperature zero. If I'm right it means that pressure of this matter is negligible against pressure due to Pauli principle. But what about situation when the matter is in neutron star locally compressed. How...

Dear PF Forum, I have question concerning neutron star and star just simply out of curiousity. 1. Can a star reach silicon burning stage then stop. It doesn't continue to iron burning stage. 2. Once a star reach iron burning stage, there's no stopping it to blast into supernova? Is supernova...

Dear PF Forum, I've been searching the answer for this particular question about neutron star in google, but I don't find it, yet. 1. What is the temperature of a neutron star, right after it is formed from supernova? 2. Can anybody give me some timeline about neutron star cooling down? 3. What...

Dear PF forum. Folks, what I have here may be an unimportant question. Still I'm curious to know the answer. When iron fusion happens in a massive star, it will undergo supernova. What I want to know is... 1. There are some binary (or perhaps ternary) neutron star systems. Neturon star is...

I try to find answer to quite basic question. Let's imagine neutron star and object with mass of 1 kg located far from the neutron star. Total energy of the object is ##E = U_g + mc^2##, for case when its velocity is zero and and ##U_g## is potential energy of gravitation. The neutron star have...

Neutron stars are supposed to have an upper limit in mass, beyond which they collapse into perhaps a further type of degenerate matter or a singularity. There doesn't seem to be precisely defined upper limit, but the limit is estimated to be 1.5-3 solar masses. However, a hypothetical neutron...

The fastest moving pulsars are theoretically spinning neutron stars. They probably got their velocity from a kick from a supernova like Project Orion. http://chandra.harvard.edu/photo/2012/igrj11014/ http://chandra.harvard.edu/photo/2003/b1957/closer_look.html As I understand it, neutron stars...

Homework Statement I am trying to answer the following question: Among the animals that appear in the zoo of the Universe there are black holes and neutron stars. The mass of each of these is often the order of the mass of the Sun. The radius of a neutron star is about 10 km and a certain...

I have done large amounts of research and could not find any books, sites or forums of how the strange matter in strange stars is formed. I know that the process of the formation of the strange star carries out mostly like the collapse into neutron stars and quark stars but how do these strange...

I've gotten a bit confused about the creation of the neutron star/pulsar, so I was hoping someone could point me in the right direction :) As fusion stops, when reaching the iron phase, the outer layers (hydrogen, helium, carbon... etc.) gets pulled in-wards do to gravity. This creates a bounce...

I had a question and I found a thread on PF with a nearly identical question ---Slowly add mass to a neutron star till it collapses. I learned some very interesting physics from that thread, namely the Tolman–Oppenheimer–Volkoff limit, and the significance of "9/8 of its Schwarzschild radius"...

Homework Statement Exercise 2.6 (page 28) Consider completely ionized matter consisting of hydrogen, helium, and heavier atomic species i>2. Let X and Y denote the fractions by mass of hydrogen and helium, respectively. Show that \mu_e=\frac{2}{1+X}. Approximate m_i=A_i m_u for all i, and...

Hi, I am currently working on a Sci/Fi short story where a spaceship leaving a planet will perform a gravitational assist sling through a binary neutron star system. The problem is that I have difficulty finding information about how close a planet could be to a binary neutron star system? I...

This relates to a feat in a classic Thor comic. Thor is blasted by a Graviton Bomb and "is instantly subject to a gravimetric attraction akin to that of a neutron star.". He is then "pulled irresistibly down by the incalculable increase in local gravity and is quickly buried from view by an ever...

How would you approximately describe matter in the core of underlying neutron star? I am asking for really fundamental properties. No strange matter, consider just n,e,p. A ratio, can we describe particles as free? Gas x fluid x superfluid? etc.

Is this established or is it dependent on the size of the black hole? http://www.space.com/22180-neutron-stars.html Neutron stars pack their mass inside a 20-kilometer (12.4 miles) diameter. They are so dense that a single teaspoon would weigh a billion tons — assuming you somehow managed to...

1. The problem statement & given/known data A neutron star is a collection of neutrons bound together by their mutual gravitation. The density of such a star is comparable to that of an atomic nucleus (10^17 kg/m^3). a) Assuming the neutron star to be spherical in shape and of uniform mass...

As the title of the thread suggests, I'm interested in estimating the velocity distribution of neutrons in neutron star cores. Putting T ~ 10^12K gives v ~ 15%c or more under Boltzmann statistics. Could someone provide more information or a second opinion on this estimate? Thanks.

What would happen to a neutron star (on the cusp of becoming a black hole) if it were sped up to near the speed of light? Or more easily done, if I sped up to near the speed of light. Would the additional mass from the near light speed cause the neutron star to collapse in on itself and form a...

The question is attached. I'm not sure how to approach to part (b). The energy released could be in 3 forms, the rest mass energy for those matter ejected during supernova explosion, the binding energy released as the atomic structure changed, the ejected matter carries off some kinetic...

Here is my understanding, please correct me if I am wrong, thanks At the end of the giant stage of a star, it experiences a supernova explosion, and turns into a neutron star (could be pulsar) or black hole, the explosion releases a lot of its matter. Here is what I don't understand: 1...

Hi everyone! First of all, I'm a brand new member and am looking forward to spending time on this forum, learning a bit more about science, and getting to know some of you. Anyway, here's what's been on my mind lately: I've heard that a thimbleful of neutron star material weighs as much as a...

Stimulated virtual W+, W- when supernova core--> neutron star? Weak interactions allow supernova core electrons and protons to convert to neutrons and neutrinos allowing (under the right conditions) the formation of a neutron star? Large numbers virtual W+ and W-bosons are produced in a short...

Hi All, I am preparing for PhD quals and have been looking at problems from other universities. I came across this one and am stumped on how to tackle it. " Assume that the neutron density in a neutron star is 30.1/fm (that is 0.1 neutron per cubic Fermi). Assuming T=0 and ignoring any...

Homework Statement Suppose that an earth-mas object collides with a neutron star with radius 10 km and mass 1.4 $M_{sun}$. The material of the earth-like object would wrap around the neutron star and form a thin layer on top of the original neutron star surface. Assume the material gets...

How many neutrons are in a neutron star with a diameter of 42.0 km? I was under the impression it was just (42.0e3/1e-15)^3 = 7.0048e58 but that's wrong??