Questions tagged [neutron-star]
Questions regarding a degenerate star that is mainly composed of neutrons.
137
questions
13
votes
3answers
2k views
Is there anything different about the gravitation around a non-spinning black hole and a neutron star of the same mass?
If we perform a simple experiment by orbiting identical spacecraft around a non-rotating black hole and a non-rotating neutron star of equal mass at a "safe" distance, and ignore differences ...
-1
votes
0answers
59 views
What is neutron star made of? [closed]
I know that the neutron star has neutrons but, what are the neutrons made of is the point.
0
votes
1answer
43 views
Is something wrong with my luminosity calculation?
A few million years after a white dwarf forms, its surface temperature reaches $100000\text{K}$, while its radius is $0.01R_\odot$. Would this mean that its luminosity is $\Big(\dfrac{100000}{5778}\...
1
vote
0answers
60 views
Strange matter objects other than neutron stars?
This question is about celestrial objects which are composed by exotic matter, and exotic matter I define as
states of matter that are not commonly encountered such as Bose–Einstein condensates, ...
3
votes
1answer
71 views
Are there any known neutron star - supergiant binaries?
After looking for more information about TZOs (Thorne-Zytkow Object), I came up with a question that I had trouble finding answers on the Internet. Do we know of any future TZOs, supergiants being ...
2
votes
0answers
67 views
Can a Thorne-Żytkow object be the progenitor of a modern quasi-star?
I was reading some Wikipedia articles about astronomy, and came across an interesting line:
The neutron star may also accrete sufficient material to collapse into a black hole.
Now, here is my ...
3
votes
0answers
44 views
Can mass loss via accretion occur on stellar remnants?
We know that normal stars can lose mass to a binary companion. But can this happen to neutron stars and white dwarfs? Let's say a stellar black hole is being orbited by a white dwarf or neutron star. ...
1
vote
0answers
55 views
What would happen if a neutron star merged with a white dwarf?
We've heard of neutron star mergers and white dwarf mergers. But what would result in a neutron star merging with a white dwarf? Would there be a similar super/kilonova, are there any examples of it, ...
4
votes
1answer
73 views
Can a star be massive enough to go 'supernova' yet not be massive enough to leave behind a neutron star? Or, perhaps vice versa?
From what I understand, stars that explode as a supernova at the end of their lives become either a black hole or a neutron star, and less massive stars that do not explode become white dwarves, but......
2
votes
1answer
82 views
The star that died and became the Crab Nebula and Crab Pulsar?
The supernova of this star was witnessed about 1 thousand years ago, and the star's remains are the Crab Nebula and Crab Pulsar. What is this no longer existent star called? How massive was this star? ...
5
votes
1answer
156 views
Stellar life cycle flow chart with mass conditions and time scales
I remember that in my nuclear astrophysics lecture a decade ago, our lecturer drew a large flow chart like diagram of stellar evolution in dependence of the mass of the star (in solar units) on the ...
1
vote
1answer
65 views
What about the magnetic field strength inside of an old accreting neutron star?
As the magnetic field strength outside an old accreting neutron star is thought to be small (about $10^8-10^{10}$ Gauss), what about it inside the star? Because of the superconductivity and ...
1
vote
0answers
40 views
What is the gravitational wave spectrum of an ellipsoid neutron star like?
If the star is ellipsoid instead a sphere, the wave should be rich of harmonics, not only (2*orbital frequency). Can these harmonics behave the same way, i.e. they appear/disappear together and drift (...
1
vote
1answer
64 views
How big would the supernova when a neutron star collides with another neutron star? [closed]
If two neutrons stars that are orbiting were to collide, how big would the supernova explosion be?
Would a new black hole or a new supernova remnant be formed?
1
vote
1answer
62 views
Question about redshift and effective gravity at the rotating neutron star surface
For a rapidly rotating neutron star, if consider the star as a sphere, redshift at the equator surface will be larger than at the pole. But if consider the star as an obsolate sphereiod (the ellipsoid ...
3
votes
1answer
115 views
Do neutron stars have an ergosphere?
Ergospheres are a property of black holes, and do neutron stars have it? If yes, why seldom article mentions that; if no, why can't neutron stars have this ergosphere component?
2
votes
0answers
36 views
How could we search for old cold neutron stars?
This is the inverse of Will Gaia detect inactive neutron stars? (to which the answer was "probably not").
So if Gaia can't do it, what would it take? How could such a search work, and what ...
3
votes
1answer
117 views
Assuming proton decay is false, what's the ultimate fate of a neutron star or white dwarf?
A still unproven theory that protons can decay, and have a halflife of $10^{30}$ years or so, meaning eventually all matter will dissolve because their constituent protons and therefore neutrons will ...
5
votes
1answer
653 views
Is nuclear pasta or neutron star crust iron stable outside of neutron stars?
When neutron stars collide, they crash into and kill each other in a kilonova explosion, which blasts a lot of their material into space. A huge amount of neutronium, neutron star stuff, is suddenly ...
3
votes
2answers
509 views
Is there a Vela Nebula?
The Vela pulsar is a neutron star from a supernova that exploded 10,000 years ago. It spins 11 times a second. The Crab Nebula along with the central Crab Pulsar formed 1000 years ago. This pulsar ...
2
votes
1answer
52 views
How did Fermi manage to see neutron star merger?
When the GW170817 neutron stars merger was observed by LIGO/Virgo, the Fermi gamma-ray telescope observed the event 2s after the merge. How did it know where and when to look? It must take some time ...
3
votes
1answer
75 views
Why do objects appear blue while on a neutron star?
I was playing around in Space Engine recently, and I realized I hadn't yet landed on a neutron star. This seemed like a very sensible thing to do, so I did it and chose a (relatively) well-known one ...
2
votes
2answers
103 views
Can a pulsar also be a magnetar?
I know this is a simplistic question, but I cannot find a straight answer...
Also, is it possible most or all neutron stars are magnetars and/or pulsars? It's just hard to see all of their properties ...
8
votes
2answers
237 views
How likely are planets to form after neutron star collisions?
It is well known that planetary collisions can create moons orbiting the result of the merger if they happen in the correct way, and this is how the Earth's moon is believed to have been formed. See ...
2
votes
0answers
15 views
What methodology should be used to choose the correct model for origin of QPOs in X-ray astronomy?
In X-ray astronomy, quasi periodic oscillations (QPOs) are routinely shown by black hole and neutron star X-ray binary systems in their X-ray flux. Despite being strong and easily measurable signals, ...
1
vote
0answers
74 views
What would happen on earth if there was a surge in gravitational waves [duplicate]
There are claims that when massive objects merge some of their mass is converted to gravitational energy. Such as the following links:
https://astronomy.stackexchange.com/a/38727/2305
https://youtu.be/...
1
vote
1answer
70 views
Fraction of initial mass lost (radiated) by neutron star mergers compared to black hole mergers?
GW190521 black hole merger total mass calculation and missing mass, how does this happen? notes that there are about 9 solar masses missing from the final black hole.
GW170817 is the first observed ...
6
votes
1answer
247 views
If a pulsar's rotational and magnetic axes were aligned and both aimed at us, would we see a steady radio source?
In other words, a non-pulsing pulsar?
6
votes
1answer
90 views
Do the neutrons in neutron stars emit the radio waves?
Neutrons can, especially in extreme circumstances (and large concentrations) emit electromagnetic radiation. I specifically asked about this in Physics S.E. Has a free neutron ever been shown to ...
5
votes
0answers
44 views
How is angular momentum transferred between a neutron star and its accretion disk?
Accreting neutron stars can either gain or loose angular momentum via interaction with their accretion disks. This leads to either spin-up or spin-down. Which of the two is the case, depends on the ...
1
vote
1answer
105 views
If the sun is a second or third generation star, where is the neutron star? [duplicate]
It is widely believed that before the Sun was another star, more pristine in its composition (mostly Hydrogen and perhaps some Helium). And maybe before it was yet another. This blog explains this via ...
2
votes
0answers
48 views
Is there any synthetic spectrum software for neutron star?
Is there any software that can calculate the emergent spectrum of a neutron star photosphere, for Teff is about 1e7K, density is above 1e21-1e22 cm^-3 ? Output line wavelength is about 0-100A is ...
9
votes
1answer
449 views
Why can there be several seconds of lag between a binary neutron star merger and the emission of gamma rays from the same area?
Answers to: Gravitational waves and gamma ray burst: how were the error bars determined for this speed of gravity calculation? Was $H_0$ used? go into substantial detail explaining this determination. ...
0
votes
1answer
106 views
What is the “hypothesized lower mass gap” between 2.5 and 5 solar masses?
Searching here for "mass gap" yields nothing yet. Penn State's Black hole or neutron star? LIGO-Virgo scientists find mystery object in 'mass gap' begins:
When the most massive stars die, ...
5
votes
2answers
399 views
Can the Sun contain degenerate matter?
Degenerate matter (neutronium) is hypothesized to be very dense and, at a certain amount, unstable - in the sense of collapsing on itself and causing fusion. The result would be a massive fusion ...
16
votes
2answers
997 views
Are there neutron stars whose magnetic axis and rotating axis are the same, and if so what will happen?
I know that there's probably a higher chance of having a neutron star that has its magnetic axis inclined to the rotational axis rather than having it perfectly aligned.
If they are not aligned, the ...
2
votes
1answer
92 views
Is the object a pulsar
We have a star having 1.8 solar mass. Justify any four means (measurable/ observed properties) by which you can identify that the object is a Pulsar and not a white dwarf or a Black Hole.
So one ...
2
votes
2answers
68 views
In practice, can very high magnetic fields significantly alter the dynamics of an astronomical-scale bodies?
The direct effect of magnetic fields on the dynamics (as in the movements, trajectories etc of the bodies themselves, rather than lower-level phenomena like stellar winds and atmospheric degradation) ...
21
votes
5answers
4k views
How far away are the events that caused the gravitational waves that have been detected?
A certain number of gravitational wave events have been detected. Is it possible to know how far away the mergers that caused those gravitational wave events are?
2
votes
0answers
37 views
Is the atmosphere of neutron star solid, liquid or gaseous state? [duplicate]
Neutron star has a thin layer of atmosphere consist mostly of hydrogen and helium and is about less than a metre thick on average, but what wasn't stated in many articles I read is the state of matter ...
3
votes
1answer
64 views
How does the field decay of a magnetar power the emission of high-energy electromagnetic radiation?
In Space.com's Dr. Pulsar and Mr. Magnetar? 2 Star Types May Turn into Each Other (and in the linked video) "Tom Prince, a physics professor at the California Institute of Technology and a senior ...
20
votes
1answer
371 views
Can we detect pulsars that aren't “pointed” towards us?
A pulsar is a highly magnetized rotating neutron star that emits beams of radiation through its magnetic poles, in the direction of the Earth. This makes it seem to pulse, as seen from Earth. There ...
10
votes
1answer
373 views
How can I hear (or at least detect) a pulsar at home?
Scott Manley's video Using Relativistic Raytracing &X-Rays To See Detail on Surface Of Neutron Star talks about X-ray measurements using the NICER X-ray telescope attached to the International ...
2
votes
1answer
134 views
If we accelerate a neutron star to move at speeds comparable to light would it become a blackhole because of the added energy?
Could a neutron star turn into a blackhole if it is accelerated to near luminal velocities? And if it slows down after a while, does it become a neutron star again?
3
votes
0answers
26 views
What is the “radiation sound speed” inside an accretion column?
I was trying to read "A New Two-fluid Radiation-hydrodynamical Model for X-Ray Pulsar Accretion Columns" and its follow-up paper both by West et al. and came across a quantity called "radiation sound ...
4
votes
2answers
134 views
Neutron star size in different reference frames
What is the estimated size of neutron stars observed in their reference frame and in our reference frame?
That is, how bent is space-time around neutron stars?
2
votes
1answer
159 views
Could anything consume a small black hole?
Whenever I read about black holes, it is normally involving how they devour anything that comes too close... regardless of how big anything is.
But what if it were a really small black hole vs ...
4
votes
0answers
68 views
Neutron star r-process nucleosynthesis
The $r$-process in supernovae happens when a high flux of neutrons irradiates the heaviest abundant nuclei (in the region of iron), resulting in endothermic nuclear reactions.
To the extent that at ...
3
votes
1answer
80 views
Radiation from Neutron Star impact?
As I understand it, objects falling into an old/inactive/dead/non-pulsar neutron star would be ripped apart, form an accretion disc and eventually emit a burst of radiation as they fall onto the ...
5
votes
1answer
85 views
Is there evidence of super-heavy elements in the x-ray and gamma-ray spectrums of neutron stars?
It occurs to me, that between the surface and interior of neutron stars, gravitational pressure might produce super-heavy elements and that signatures of such elements might be detectable in the star'...
