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Questions tagged [pulsar]

Questions regarding neutron stars which emit regular pulses of electromagnetic radiation.

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1 answer
60 views

Why does an aligned rotator (pulsar) radiate?

It seems that the model of an "aligned" rotator is a common model to describe most features of isolated pulsars: Since the first works on pulsar magnetospheres, a stationary force- free ...
11 votes
3 answers
3k views

Do Pulsar stars make actual sounds?

From my understanding of pulsars, pulsars do not produce sound, but radio telescopes can record the radio waves they emit, which can be interpreted as sound. The radio waves are electromagnetic waves, ...
13 votes
2 answers
1k views

Why are the magnetic poles of a pulsar so far off the rotational axis, yet stable?

My understanding is that a pulsar is a neutron star whose magnetic poles don't coincide with the rotational poles and whose magnetic poles sweep through Earth (allowing us to hear radio noise). If we ...
17 votes
4 answers
802 views

Does the observed period of a pulsar change with the time of year?

Over in the Physics SE a question was posted asking about the difference in the time dilation of the Earth between perihelion and aphelion: Does Earth experience any significant, measurable time ...
4 votes
0 answers
81 views

I was finding the period of crab pulsar using efsearch(xronos)

I was finding the period of crab pulsar(one orbit data from ASTROSAT/laxpc) using efsearch (heasarc/xronos). Despite considering period = 33ms, I am not getting sharp peaks at higher Resolution for ...
4 votes
1 answer
337 views

How long would we survive an approaching neutron star?

I recently came across PSR B1620−26. A neutron star that captured a sun like star with an orbiting planet. The system went through several stages of development, but through it all the orbiting planet ...
2 votes
1 answer
135 views

What are the differences between different types of flux density in radio astronomy?

I am new to radio astronomy and have started to analyze some radio observational data of pulsars recently. I am wondering about the differences between "peak flux density", "integrated ...
3 votes
1 answer
108 views

Could the revolution of super-massive black holes around each other create a pulsar-array gravitational wave signal despite 'final parsec' problem?

Some commentators on the recently-observed very-long-wavelength gravitational wave signal involving pulsars, like Dr. Becky Smethurst, have implied that it might not be merging supermassive black ...
6 votes
3 answers
291 views

Can't pulsars and stars be used for gravitational wave measurement?

Suppose that we collected photons from a distant star, and they arrive regularly at 15 photons every microsecond onto a CCD, when a gravity wave bends space time, wouldn't the regular 15 photons graph ...
7 votes
1 answer
226 views

What are realistic and unrealistic values for the high energy gamma ray spectral indices of pulsar wind nebulae?

This summer, I was working on a project fitting very high energy gamma ray spectra of the Crab Nebula, a pulsar wind nebula. At energies about $\sim$1 TeV, a simple power law suffices, i.e. $\phi(E)\...
5 votes
1 answer
65 views

How to interpret illumination in "pulsar cannonball" image

This beautiful image (from APOD) looks like the trail of the ejected pulsar is illuminating a ball of gas and dust. My eye sees patches of light and shadow, but sometimes images can be deceptive. What ...
0 votes
0 answers
163 views

How much would you weigh at the equator of the fastest spinning pulsar?

Assuming you have a mass of 70 kg, what would your weight be on the equator of PSR J1748−2446ad?
4 votes
1 answer
266 views

Acronyms in astrophysics: is there a place that collects them all anywhere on the internet? And what does PSN mean on the TNS server?

Acronyms in astrophysics: is there a place that collects them all anywhere on the internet? And what does PSN mean on the TNS server? Is it "possible supernova" or "pulsar" ...
2 votes
1 answer
87 views

Pulsar rotation linear velocity

I recently came upon millisecond pulsars. I knew of pulsars, I had never guessed though that they can spin so fast. I believe I had read about a pulsar rotating at about 10-15Hz. But I just read about ...
8 votes
1 answer
1k views

Rotation direction of Pulsars

Pulsars are rotating neutron stars observed to have pulses of radiation at very regular intervals that typically range from milliseconds to seconds. It has a very strong magnetic fields which funnel ...
6 votes
1 answer
147 views

What are the main ways that pulsar "glitches" are noticed and documented? Do they have to be caught in the act of glitching to be catalogued?

This answer to Is there any well-populated list or database of pulsar "glitches"? mentions two large databases; (Jodrell Bank and ATNF's pulsar catalog) but neither question nor answer ...
7 votes
1 answer
392 views

Is there any well-populated list or database of pulsar "glitches"?

Besides listing which pulsars have ever actually glitched, it would hopefully also include some historical data on their periods before and after they glitched.
1 vote
0 answers
35 views

What are the typical density and temperatures in Pulsar Wind Nebulae?

What are the typical density and temperatures in Pulsar Wind Nebulae? Also, how do we typically observe/estimate these values?
9 votes
2 answers
421 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 ...
3 votes
0 answers
212 views

Did a watch company really try to sue radio astronomers for using the word "pulsar"? If so, which astronomers?

After about 48:37 in the really wonderful video Jocelyn Bell Burnell Special Public Lecture: The Discovery of Pulsars (linked below) Dr. Bell Burnell describes the ...
5 votes
1 answer
510 views

Is "magnetars don't last long — just a year to a few years" really true? Is it a misquote or perhaps taken out of context?

NASA's Two Sides of the Same Star discusses the relationship between pulsars and magnetars and contains a video also linked below. At 02:13 it quotes "Tom ...
6 votes
2 answers
334 views

Why do pulsars turn "off" from rotation?

I was looking at the Pulsar wikipedia article and I came across an interesting aspect that said pulsars turn off from rotation: When a pulsar's spin period slows down sufficiently, the radio pulsar ...
5 votes
1 answer
566 views

How bright is the Crab Pulsar's 30 Hz modulation in visible light? What color is it?

This answer to Has great eyesight been necessary for astronomers? mentions Astronomer Jocelyn Bell Burnell's recounting of a likely first visual observation of a pulsar. This can be found for example ...
1 vote
1 answer
190 views

Is the smaller companion of Pulsar J0453+1559 still the smallest known neutron star? Was it further confirmed to be a NS after Martinez et al. (2015)?

@ProfRob's Physics SE answer to What is the theoretical lower mass limit for a gravitationally stable neutron star? was linked just now in their answer to Can a neutron star ever be less than about 1....
4 votes
1 answer
415 views

What exactly is "the rotating lighthouse model" in the context of a double pulsar?

The introduction to Testing the rotating lighthouse model with the double pulsar system PSR J0737-3039A/B (open access) says: The double pulsar system PSR J0737-3039A/B was discovered by Burgay et al....
1 vote
0 answers
136 views

Pulsar signal periodicity detection algorithms?

I am currently working on pulsar signal periodicity detection. Most of the algorithm or paper which i read they use FFT (Fast Fourier Transform) and FFA (Fast Folding Algorithm ). Do we have any other ...
2 votes
0 answers
43 views

Convert pulsar data to sound

I have a filterbank data (say name.fil) which I have dedispersed and stored into name.dat file using PRESTO. May I ask for detailed steps and explanation on how to convert that data to sound?
2 votes
1 answer
114 views

How is the polar angle of a pulsar beam determined?

I just read the question "What is a typical polar angle of a pulsar beam?" and I was surprised that it had an answer. I thought there was little real information besides the timing of the ...
7 votes
1 answer
287 views

What is a typical polar angle of a pulsar beam?

I've found many articles on the geometry of pulsar beams, but I have not been able to find what would be a typical angle for the beam cone. Illustrations I've found seem to look like it might be 1 or ...
2 votes
1 answer
526 views

How to determine arrival time delay given dispersion measure?

In an online textbook, the following formula is given to calculate the arrival time delay between two frequencies, $v_1, v_2$ in a dispersed radio pulse: $$t_1 - t_2 = 4.15 \cdot DM [(v_1/\text{GHz})^{...
3 votes
2 answers
559 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 ...
1 vote
0 answers
37 views

What is superradiance?

What is superradiance? I came across this term recently (used widely to explain fast radio bursts). After googling a bit, what I understand is: When several atoms are confined in a very small area and ...
0 votes
1 answer
69 views

Why do some pulsar planets have designations with a capital letter at the end?

The pulsar PSR B1257+12 has three planets. Most triple-planet system have designation foo b, foo c, and foo d. However, I noticed that the three planets of this pulsar (PSR B1257+12) have a ...
5 votes
1 answer
636 views

Is the pulsar map on the Pioneer/Voyager probes only meaningful for earthlings?

The Pioneer probes brought plaques (and later the Voyagers two golden discs) with a "pulsar map" imprinted on them. The purpose of the map is to make the position of the Sun clear for an ...
2 votes
2 answers
261 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 ...
6 votes
2 answers
524 views

How did Jocelyn Bell Burnell discover the periodicity of CP 1919?

According to Wikipedia, in 1967, a radio signal was detected using the Interplanetary Scintillation Array of the Mullard Radio Astronomy Observatory in Cambridge, UK, by Jocelyn Bell Burnell. The ...
6 votes
1 answer
355 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?
5 votes
0 answers
79 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 ...
5 votes
2 answers
244 views

Can a pulsar hit us with both beams?

Can a pulsar have an axial tilt close enough to $90^\circ$ to hit us with both beams for two pulses per rotation?
5 votes
3 answers
567 views

How do we know pulsars have two beams?

Pulsars are neutron stars the emit a beam of electromagnetic radiation that is not aligned with their rotation axis. So we can only see a neutron star as a pulsar if the beam crosses Earth's path. ...
16 votes
2 answers
1k 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 ...
16 votes
3 answers
2k views

What is the probability of seeing a neutron star as a pulsar?

Pulsars are neutron stars that emit a beam of electromagnetic radiation that is not aligned with its rotation axis. If the Earth passes through that beam of radiation, we see a pulsar. Pulsars are ...
13 votes
1 answer
1k views

Pulses from a pulsar

What is/was the motivation behind attributing the pulses received from a pulsar to the rotation of an object (neutron star) and emission from the magnetic poles (of the said neutron star), given that ...
20 votes
1 answer
3k views

What causes fast moving pulsars to move so fast?

This article investigates the traces left in the ISM by fast moving pulsars. Is there a mechanism specific to pulsars that causes them to move so fast, or are there just as many fast moving stars? ...
6 votes
2 answers
167 views

Do pulsar beams interact with the interstellar medium?

Pulsars are rotating objects that emit a beam in a direction that is not aligned with the axis of rotation. Because of this, we see them as a periodic pulse. If the beam isn't towards us, we don't see ...
21 votes
1 answer
598 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 ...
1 vote
1 answer
173 views

How to improve efficiency in periodicity detection?

Our data set has $10^4$ data points, but has a long baseline and many gaps. If we bin the data, there would be $10^8$ data points ($[t,\rm {value}]$), but only about 1% are non-zero values. How to ...
1 vote
1 answer
240 views

Why pulsar pulses are so extremely regular?

It's often said that the pulses of the pulsar have a very precise period, which helps to detect easily exoplanets that cause fluctuations in the time of arrival (TOA) of the pulses. Anybody knows why?
11 votes
1 answer
1k 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 ...
3 votes
0 answers
78 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 ...