Neutron star Definition and 175 Threads

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??

Homework Statement The Crab Nebula is a cloud of glowing gas about 10 light-years across, located about 6500 light years from the Earth (the figure (Figure 1) ). It is the remnant of a star that underwent a supernova explosion, seen on Earth in 1054 a.d. Energy is released by the Crab Nebula...

I thought readers would be interested in this interesting article today on black hole and neutron star mergers and the very small possibility of instantaneous sterilization and extinction of all life on earth:http://www.space.com/22231-gamma-ray-bursts-neutron-stars.html...

Hi all, this is my first post here and i apologize if some rules aren't followed. I have to complete the Project 13.1 (studies of neutron stars: p 346-350) http://www.cec.uchile.cl/cinetica/pcordero/MC_libros/Hjorth-Jensen2008.pdf When browsing using pdf pages 346 to 350, assignments 1...

Hello, Can somebody please tell me in details about the rotation speed of a neutron star? Does it rotate very fast and then slows down? Thanks.

Hello, I want to understand: just as the Crab Nebula is the result of SN 1054 and has a neutron star spinning at the center: (a) Does all supernova produces a nebula? (b) Does all supernova remnant has a neutron star at the center? (c) What is the outcome of Kepler supernova i.e. SN...

Pulsars -- Rotating neutron star produces EM radiation? Hello, If a neutron star is composed of neutrons, which do not carry any electric charge then how it's rotation produces pulsars which are electromagnetic radiation? Thanks.

On decays I have only a preliminary understanding. I was looking up the half life of a neutron for another reason. The value I found for neutron decay for a free neutron was 10.3 seconds. Hope that's reasonably accurate. Anyways knowing that neutrons are stable in a nucleus held together...

I wrote a paper in the physics department's student newspaper at my school, which described why, in my opinion, I considered a neutron star's surface as the smoothest surface in the universe, I considered the space between the particles at the surface (thousands of times smaller than at TPN...

I was wondering today what is the colour of pure neutrons confined together, I'd guess it's either completely black or white, because it doesn't have the electric orbitals needed to generate different wavelengths. I'm generally guessing it just reflects light and is therefore what... maybe a...

Homework Statement Under some circumstances, a star can collapse into an extremely dense object made mostly of neutrons and called a neutron star. The density of a neutron star is roughly 10^{14} times as great as that of ordinary solid matter. Suppose we represent the star as a uniform, solid...

Ok, I know neutron stars are mainly composed of neutrons. But also, they have some protons and normal nuclei at their surfaces. Is this crust of protons needed to keep the neutrons below stable? As in, if it disappeared, would the neutrons below start decaying back to protons to form its...

Hey, So i just read 2 articles, the first talked about the mathematical problem of 'packing', IE how many smaller objects of the same size can fit inside a shape without overlapping or covering the boundaries of the shape. and the second article was talking about a recent neutron star that...

Hello. I am wondering what are the properties of matter at the core of a neutron star. I read that it could be quark matter of strange matter, but overall uncertain. How can strange matter form if strange quarks decay very quickly into up quarks (the state of matter would last very shortly), and...

a. it rotates faster b. it is smaller c. it is more luminous d. it has stronger pulses I'm stumped on this practice question for my final. I'm thinking that a. and d. contradict each other since doesn't an older, slower rotating neutron strong emit longer, stronger pulses? C. seems to...

Is there a well-established theory for temperature and cooling processes of neutron stars as a function of time?

Neutron star is said to have masses so compact that 10 miles of it would have more mass than the sun. For example two neutron star collides, can a small fragment be separated from it forming a meteor? And if a small piece were to enter Earth atmosphere and reach land. Would the neutron star as...

After a supernova what compels the left over core to be either a neutron star or a pulsar? is it decided before or after explosion? any thoughts would be appreciated.

Specifically, what happens to the identical fermions in a neutron star as the neutron star collects additional mass that makes it into a black hole. Fermions cannot occupy the same state according to the Pauli exclusion principle, what happens to them in the black hole?

Neutron stars are held together by extremely strong gravitational force. What would happen to a chunk of the star if it had been removed and left to stand alone? Same question for a chunk of a white dwarf?

I recently read an article that said that experiments in synchotrons had indicated that an electron was the most spherical object in the universe. It stated that if an electron were the same diameter as the solar system, the variation in its diameter would be less than the thickness of a human...

From https://www.physicsforums.com/showthread.php?t=40391 in gravitational time dilation. At the center of neutron star PSR J1614-2230 at 1.97 SM mass of Sun 1.9891×10^30 kg mass of PSR J1614-2230. 4 ×10^30 gravitational constant = 6.67300 × 10-11 m3 kg-1 s-2 radius(rough estimate) =...

Say a core collapse event of a massive star occurs, forming neutron star matter in its core. However, the explosion manages to eject enough core mass such that the remnant is below the Chanrasehkar limit. At this point, gravity would no longer be able to overcome electron degeneracy pressure...

There aren't any electrons on a neutron star right? They all get squooshed into the protons to make the neutrons. Am I right about that?

Neutron stars are thought to be rotating in a way that their beems are seen as the pulses. The beems are not aligned with the axis of rotation. What is the current theory about the speed of the axis of rotation? Are they spinning and rotating on both axis?

Can simple mass accretion turn a neutron star into a Black Hole, or does a BH require temperatures and pressures from the collapsed massive star?

Like the question says, would a neutrino be stopped by the very high density matter in a neutron star? IH

If a super-duper-hyper-energetic particle like the OMG particle (refer http://en.wikipedia.org/wiki/Oh-My-God_particle) were to impact the surface of a neutron star, could the tremendous impact density it creates lead to the beginnings of an embryonic black hole that would (slowly/quickly?)...

http://arxiv.org/abs/1101.4298 The missing link: Merging neutron stars naturally produce jet-like structures and can power short Gamma-Ray Bursts Luciano Rezzolla, Bruno Giacomazzo, Luca Baiotti, Jonathan Granot, Chryssa Kouveliotou, Miguel A. Aloy (Submitted on 22 Jan 2011) "Short Gamma-Ray...

Neutrons have no charge, and in neutron stars we have matter that is only made of tightly packed neutrons. The mass is very great due to density. If I were to go fetch a baseball sized ball of neutron star matter from a neutron star and lay it on hard concrete ground... Other than making a...

I know that nuclear fusion is the source of energy for our sun and most of the other stars. Neutron stars and white dwarfs have very high surface temperatures. What is the source of their energy?

What are White Dwarfs & Black Dwarfs? And what are Chandrasekhar's limits? Also I want to know about Neutron Star.

A letter in the current issue of Nature: ==quote== A two-solar-mass neutron star measured using Shapiro delay P. B. Demorest1, T. Pennucci2, S. M. Ransom1, M. S. E. Roberts3 & J. W. T. Hessels4,5 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, Virginia 22093, USA...

When a neutron star flucuates into a black hole does the gravity increase tenfold? Or does the neutron star gravity (while turning into a black hole) increase as expected with the addition of more mass?

Is there any direct evidence that black holes are smaller in size than (less massive) neutron stars?

Firstly, I would like to say hello to everyone as this is my first post. I am an artist working a personal project that will be a visual investigation into the effects of a collision between a Neutron Star and Earth. The star would have a fully collapsed core at 1.5 solar masses (maybe...

Homework Statement If a neutron star were bright enough to see its surface with a telescope, we'd be able to see not just the hemisphere facing toward us but also part of the far hemisphere. Explain why and estimate the latitude above which the far side could be seen. Homework Equations...

How can you measure the mean density of a neutron star if your only told its mass is three times that of the Sun?

Edit: nvm

when two neutron stars collide, do they creat both a balck hole and release gamma rays or does it happen in stages?

Homework Statement Assuming a neutron star is made from an incompressible material, what is the hydraulic pressure 50m below the surface? Mass = 1.98x10^30kg Radius = 10km 2. The attempt at a solution g=GM/r^2 = (6.67x10^-11 x 1.98x10^30)/ 10000^2 = 1.32x10^12 m/s^2 P=P_{0} + \rhogh Pa...

Say we slowly add mass to a neutron star till it collapses to a black hole. Just before it does has time in the neutron star almost come to a stop? Is the passage of time different for different locations in the neutron star just before it collapses? Would the strings of string theory come to a...

If a neutron star accumulate materials from its companion star ,then it's mass exceeded Tolman–Oppenheimer–Volkoff limit, it will collapse into a black hole! My question is ,in this case ,it will produce "gamma-ray burst"?

How many neutrino emission mechanism, that causes the cooling of star, are there in neutron star? And How, what equation, to calculate the emissivity of each mechanism? thankfully, First

If a person could orbit close to a neutron star what color would it appear to be? I have always imgained them to be blue, but this might be totally wrong. :rolleyes:

Homework Statement Neutron stars, such as the one at the center of the Crab Nebula, have about the same mass as our sun but a much smaller diameter. If you weigh 650 N on the earth, what would be your weight on the surface of a neutron star that has the same mass as our sun and a diameter...

Does anyone know if an average Neutron star with a diameter of 10 miles, was headed towards Earth.. would our Nuclear weapons be able to physically destroy it? Assuming our technology can provide a direct hit, and do it in time. If so, then how many Megatons would the Nuke need to be, and how...

What is the minimal mass of a neutron star, if the semi empirical mass formula is used?

Here's one for everyone to ponder.. Firstly, this question has always bugged me since I was born. It's not impossible to imagine an Alien civilization 1.5 billion years more advanced than us, using the method of 'Hurling Neutron Stars at 99% the speed of light, to destroy planets and their...

A neutron star cannot spin with less than a certain critical period, or else it will start to lose mass from its equator due to the “centrifugal” force. Estimate this period.