Astronomy Stack Exchange
Astronomy Stack Exchange

Questions tagged [pulsar]

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

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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 dilation at perihelion? Rather to my surprise it turns…
John Rennie
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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 fact that pulsars have not been resolved yet in…
user30981
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Crab Nebula Time Period

I've learned that the time period for a rotating neutron star, i.e., a pulsar is very accurate and can be used as an interstellar clock. But according to Walter Lewin's 8.01 Lec 19 on classical mechanics, he says that the rotational time period of…
shortstheory
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What is the significance of the discovery of a pulsar flipping between radio and x-ray emissions?

This morning on the radio I heard about the discovery of a pulsar that, due to its proximity to a companion star, was flipping between a state where it emitted radio waves and one where it emitted x-rays. The flipping between states was said to be…
Gavin Simpson
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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.
bigjosh
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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 degrees. What range of angles might you expect…
Jeff Wolski
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How to tell a pulsar is rotation-powered or accretion-powered?

We need to calculate P/Pdot? A pulsar may switch between theses two states. For a rotation powered pulsar, it can pulse and, the pulsed Lx can be much larger than the luminosity given by its rotation? If Lx is very small, smaller than the…
questionhang
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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. The common representation is that there are two…
usernumber
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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?
smithkm
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Does Doppler shift affect apparent pulsar frequency?

We know that redshift and blueshift is the result of the frequency of light waves reflected or emitted by an object lengthening or shortening due to the relative velocity of the observer moving away or toward the object. This is the Doppler…
Kromey
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which pulsar has the longest spin period so far?

Vela X-1 has a 283s spin period, while this one may have a 2.7hr spin period. However neither of them is included in ATNF catalog. They are not included in $p-\dot{p}$ diagram either. The longest period is just about 10s in this diagram. My question…
questionhang
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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 J1748-2446ad, which rotates at the astonishing…
Stavros Souvatzis
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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 pulses, and it seems like any given timing could be…
Mark Foskey
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What does a pulsar look like if viewed from above?

Have we ever seen a pulsar directly from above or below it's spin axis? I am wondering if a pulsar seen from this angle would appear to be constantly spinning or if it would just appear like a normal star.
Jimmery
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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?
Razor
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