What is Pulsar: Definition and 61 Discussions

A pulsar (from Pulsating Radio Sources) is a highly magnetized rotating compact star (usually neutron stars but also white dwarfs) that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth (similar to the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays. (See also centrifugal mechanism of acceleration.)
The periods of pulsars make them very useful tools for astronomers. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered around a pulsar, PSR B1257+12. In 1983, certain types of pulsars were detected that at that time exceeded the accuracy of atomic clocks in keeping time.

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  1. ZX.Liang

    I Circular polarization and linear polarization of pulsars

    Is there more circular polarization or linear polarization in the radiation flux of pulsars? Have any papers discussed this issue?
  2. K

    I How does an observer moving at relativistic speeds perceive a pulsar?

    Let us suppose our velocity towards a distant neutron star roughly equated to a dilation factor of 10. On board our vessel we are equipped with a NIST-F2 atomic clock . Since the clock travels with us, it also experiences the same dilation; thus, in our frame, the clock keeps time the same as...
  3. fresh_42

    I Double Pulsar: 16 Year Study Validates Relativity

    I'm not sure if this belongs to astronomy or GR. But as it - once again - proves Einstein right, I posted it here for all who need another paper to conquer all who doubt. And I think it is an interesting paper (53 pages), at least from my layman's point of view...
  4. U

    The angular acceleration and period of a pulsar

    for (a) ##T=\frac {2\pi}{\omega}## $$\omega=\frac {2\pi}{T}$$ $$\frac{d \omega}{dt}=\frac {-2\pi}{T^2} \frac {dT}{dt} $$ $$\alpha=\frac {-2\pi}{(2.94*10^-15)^2} = 7.27*10^29 rad/s^2$$ for (b) I'm understand that it's infinity, because the period is increasing indefinitely, so it's slowing...
  5. koroshii

    I Acquiring a Small Dataset of a pulsar signal

    I am taking a class in signal processing. We have a final project in which we seek out "real-world" signal data and process and analyze it, and write a report on what we figured out. I thought it would be interesting to put my own interests into it and try to analyze a pulsar signal. My idea is...
  6. lomidrevo

    B See the first precise pulsar surface map

    Link to article: https://www.nasa.gov/feature/goddard/2019/nasa-s-nicer-delivers-best-ever-pulsar-measurements-1st-surface-map Link to accompanying video:
  7. S

    B What Are the Force and Speed of Pulsar Winds?

    I keep reading on the internet that pulsar winds can travel at relativistic speeds. If so, how strong are these pulsar winds? What kind of force would they carry?
  8. S

    What does it sound like inside a pulsar?

    A star is kind of a huge nuclear explosion. Things are smashing into each other all the time, bouncing off, and all this movement creates vibrations, so there's actually sound sound inside any star. Pulsars have produced radio waves, which have been converted into audible sound waves, thus...
  9. R

    B Pulsar Clock: The Mystery of Slowing Rotation in a Spaceship

    If a pulsar with a period of exactly 1 second was put in a spaceship and accelerated up to V where would the energy come from to slow the rotation of the pulsar ?
  10. S

    I Can Tidal Locking Occur in Binary Neutron Stars Before Merger?

    How many neutron stars are binaries of other neutron stars? Hulse-Taylor binary, discovered in 1974, has orbital period of 7,75 hours. And the pulsar component rotates at 59 milliseconds. The orbit is also eccentric, from 1,1 to 4,8 solar radii. Expected to merge in 300 million years. PSR...
  11. J

    B What would happen if you take a piece of a pulsar

    Hi, what would happen if you took 1 cubic meter of matter from pulsar into empty space what would happen does the matter will expand since there is no more strong gravity does will it explode ? would like to know your answers
  12. M

    B Pulsar Beams: Spin, Wobble, & Projection

    Is the beam of a pulsar projected perpendicular to its spin? If so, is the "pulse" due to wobble?
  13. mpolo

    Can electrons move faster than Light?

    I just read this article and it sounds like they are claiming that there are electron currents moving 6 times the speed of light? Am I understanding this correctly. The article title is "Faster-Than-Light Pulsar Phenomena"http://www.universetoday.com/49646/faster-than-light-pulsar-phenomena/
  14. Jonathan Scott

    A The brightest, furthest pulsar in the universe

    An interesting challenge for the theorists: https://phys.org/news/2017-02-brightest-furthest-pulsar-universe.html An Ultra-Luminous X-ray source (ULX) has been found (NGC 5907 X-1) which definitely seems to contain a pulsar, yet it appears to be far more powerful than other such sources which...
  15. A

    I China launches X-ray Pulsar NAVigation satellite

    China launched five small satellites Thursday, including the X-ray Pulsar Navigation satellite that eventually could help spacecraft headed for deep space navigate, the latest piece of China’s ambitious space program, NASA Spaceflight.com reported. The X-ray pulsar, developed by Aerospace...
  16. Garlic

    I Youtube video about the sound of a pulsar

    Hello PF, I found this youtube video about the sound of a pulsar, and I have been wondering if this sound is really the radio signals of a pulsar converted into sound, or something fake. Thank you Link:
  17. W

    I Could pulsar timing arrays see primordial gravity waves?

    Im wondering if pulsar arrays could see primordial gravity waves? I have understood the only way to seem them would be to a) via indirect imprint on CMB polarisation b) direct viewing via some gigantic space based interferometer like Big Bang Observer However I was looking at this image...
  18. R

    Why do pulsars emit radiation from both poles?

    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...
  19. B

    What are the basic mechanics of pulsar IGR J1104-6103?

    See: https://en.wikipedia.org/wiki/IGR_J11014-6103#/media/File:Lighthouse_nebula.jpg IGR J11014-6103 has the largest observed jet in the Milky Way. What are the basic mechanics IGR J11014-6103?: How fast is this neutron star pulsar moving with respect to the center of the cloud (1000 km/s?) and...
  20. Stephanus

    What information can be derived from the pulsars featured on the Voyager plate?

    Dear PF Forum, I've read the current Featured Thread in November 12nd, Lost in the Milky Way scenario. It's a good thread. But I want know what pulsar is. https://en.wikipedia.org/wiki/Pulsar A. Does pulsar(s) have unique frequency? Given the number of pulsar in our galaxy and the vast range of...
  21. Robsta

    Distance to pulsar with plasma dispersion relation

    Homework Statement Pulsars are stars that have suffered gravitational collapse. They rotate rapidly and emit a narrow beam of radiation. The pulse lengths, at the earth, are ∼1ms and the periods are ∼1s. Within a few months of the discovery of pulsars distance estimates were obtained by...
  22. Z

    What is the mass and equatorial radius of the Crab Pulsar?

    The most widely cited figures are 1.4 solar masses and 10 km radius. However, tracing the references back to their sources I find that these are just canonical numbers for a generic neutron star. Either the original paper says that explicitly or says something like, "Let's assume a mass of...
  23. |Glitch|

    Evidence of an asteroid encountering a pulsar

    The paper goes on to describe asteroids "formed from supernova fallback material" falling into the pulsar. Why would the asteroids be formed after the supernova? More importantly, how could an asteroid form from supernova remnants? If a star with less than ~9 solar masses had planets and...
  24. Astronuc

    PSR J0348+0432, Pulsar with white dwarf companion

    Apparently this binary system is providing yet further confirmation of GR. It is only the second NS with a precisely determined mass ~ 2 solar masses. Pulsar-White Dwarf Pair Proves Einstein’s Theory of Relativity http://www.sci-news.com/astronomy/article01046.html...
  25. A

    Hulse-Taylor pulsar and GR what if orbital velocities were higher?

    The Hulse-Taylor (PSR B1913+16) binary pulsar 'observed vs. predicted' orbit decay is one of the great validations of GR. The orbit decay over the recording period of 30+ years is very close to GR prediction as per predicted energy loss through gravitational waves. Hulse-Taylor experiment is...
  26. Y

    Pulsar radiation at quantum level

    Hey, as per i know pulsars emit EM radiation . . . Can anyone please explain the reason behind this in terms of quantum mechanics. I want to know what happens at the quantum level. All I know is that it takes place due to misalignment of magnetic and rotational axis... I am in high school...
  27. M

    Pulsar Orbiting another body, doppler shifted pulse rate problem

    Hey all, new to the forum. Had a tough question that I was trying to work out about an orbiting pulsar and the doppler shifted pulse period. So, if we have a pulsar orbiting some central object in circular orbit, with a constant orbital velocity v, and a pulse period of P_0, how can we write...
  28. D

    A pulsar gravitation question

    A pulsar – a highly magnetized, rotating neutron star – has a radius of 9.98 Km, a mass of 1.98 × 1030 kg, and revolves around itself at a rate of 30.02 times per second. Calculate the nearest distance that a person 1.99 m tall could approach the pulsar without being pulled and torn apart...
  29. M

    Can quasar gets converted into pulsar?

    Quasars are galaxies which are very active at centre pulsars are dense stars... Since pulsars rotate very fast it can be a quasar gone crazy?
  30. S

    What time of year observations of crab pulsar were made

    Hi There I left a related post to the problem I am having with the crab pulsar a little while ago but would like to repost in a much more coherent manner than was done the last time - I would like first to state the problem and then state my approach to solving it. hopefully then any incorrect...
  31. S

    Angle of crab pulsar to the ecliptic

    Hi there Can any1 tell me, what is the angle that the crab pulsar makes to the ecliptic? - (I am trying to make calculations that require knowledge of the radial velocity between the Earth and Crab) Thanks
  32. C

    Why do pulsars emit radiation?

    If a current loop does not radiate EM waves, then why does a pulsar? If the charge is evenly spread through the pulsar and its rotation creates the B field. I Don't understand why it radiates?
  33. K

    Neutron Star or a Pulsar - what decides

    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.
  34. teroenza

    Binary Pulsar Orbital periods.

    Hello, I am doing a very brief presentation for school on gravitational radiation and wanted to include a figure for the orbital periods of binary pulsars. I can find the rotation rates of individual pulsars on Google but can't find a figure for orbital periods of binaries. This does not...
  35. B

    Can a spaceship land on a pulsar?

    For example if the pulsar is rotating with a fourth of the speed of light? Or more generally, what effect does the rotation of an object have when it comes to landing on it? Thanks
  36. S

    Do all pulsars have a Pulsar wind nebula?

    Intuitively I would say no because it seems like a big call but at the same time the high energy effects rely on the interaction between magnetic fields and gas don't they? Any tips or just an idea of where I can find out would be awesome
  37. R

    Deriving the Claim: \sin^2\theta/r Conservation in Pulsar Gamma-Ray Emission

    When I study the mechanism of gamma-ray emission from pulsars, I got a statement saying that the quantity \sin^2\theta/r is conserved along any dipolar magnetic field line. Does anybody know how to derive this claim? Thanks in advance.
  38. A

    What Would Happen if Our Sun Became a Pulsar?

    If our sun was replaced by a pulsar, would our solar system be sucked into it because of the increased gravity? How long would it take? Would we burn up because of the increased heat? How long would it take? Does it still emit visable light or only x-rays etc..? Would the light on Earth be...
  39. A

    How Should a Spacecraft Navigate Towards a Pulsar to Optimize Its Path?

    Homework Statement In the year 2212, humans send an unmanned spacecraft towards a faraway pulsar. The pulsar sends the signals in a plane (say plane A) which passes through the Earth. The spacecraft is designed in such a way that it has a continuous and a constant magnitude of...
  40. M

    Pulsar Timing Accuracy: Fractional Instability to 10^-15

    I've read the following statement: "Fractional instability of some pulsars is comparable with the one of atomic standards and reaches the level 10^{-15}" This was the first sentence of the paper of Alexander Rodin: Detection of GW by pulsar timing But no citation in there. 1) Could you...
  41. J

    Pulsar Angular acceleration question

    Homework Statement The problem is as follows. A certain pulsar (a rapidly rotating neutron star) has a period of rotation of 0.033s, and this is observed to be increased at a rate of 1.26(10^(-5)) seconds per year. what is the value of the angular acceleration in rad/s^2? Homework...
  42. P

    How many times does the pulsar rotate in 30.0 days?

    Homework Statement I have this problem for my homework: Time standards are now based on atomic clocks. A promising second standard is based on pulsars, which are rotating neutron stars (highly compact stars consisting only of neutrons). Some rotate at a rate that is highly stable, sending out...
  43. C

    Does electromagnetic radiation from pulsar stars

    Does electromagnetic radiation emitted by pulsars carry enough energy as to make the gravity created by these emissions significant enough to gravitationally effect distant objects many light years away? In other words, can a pulsar star or a neutron star, effect distant planets or even...
  44. D

    Pulsar Particle Beams: Speed & Collisions

    how fast are the particles in the 2 beams of a Pulsar traveling? and what happens when two of those beams intersect? do those particles collide at extremely high velocities like in particle accelerators?
  45. S

    State of Pulsar Theory & Observations

    It is interesting to compare pulsars to quasars. If one assumes the massive compact object at the center of a quasar is a physical object that has properties, is it similar to what creates the pulsar and magstar observations? What are the pulsar and magstar observations? What are the quasar...
  46. P

    Is There a Maximum Rotational Velocity for Pulsars?

    What is the fastest Possible rotational velocity for a pulsar ? There must be a point where it requires an infinity of energy to go any faster. There is also a point where it becomes a black hole. How exactly does velocity relate to a fundamental shift in terms of how matter changes...
  47. B

    New Pulsar Emission Mechanism?

    In papers presented this week to the American Astronomical Society, Andrea Schmidt and John Singleton of Los Alamos National Laboratory provide detailed analyses of several pieces of observational data that suggest that pulsars emit the electromagnetic equivalent of the well-known "sonic boom"...
  48. L

    Centripetal Acceleration of pulsar

    Homework Statement Pulsars are neutron stars that emit X rays and other radiation in such a way that we on Earth receive pulses of radiation from pulsars at regular intervals equal to the period that they rotate. A certain pulsar has a period currently of length 33.085m/s and is estimated to...
  49. F

    How to Calculate the Magnetic Field Strength of a Pulsar?

    hay I need the following expression B^2V of a pulsar. B is the magnetic field and V is the volume. I can do this in a strong approximation with B = 10^8T and v = 10km but I would like to do it properly. Therefore I choose the magnetic field of a dipol B(r) = mu_0/(4*pi*r^3) (3*r(r*m)...
  50. T

    Pulsar Radius from its rotational period

    Homework Statement A pulsar emits bursts of radio waves with a period of 10 ms. Find an upper limit to the radius of the pulsar. Homework Equations Not Sure The Attempt at a Solution Can anyone help with this, I cannot see how the period will help tell you the upper limit to the...
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