PULSARS
- SCI & TECH
News:
Pulsar glitch: How
physicists are making sense of a cosmic mystery | Explained
What's
in the news?
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In 1969, scientists noticed an abrupt and
brief increase in the rotation rate of a pulsar. It was the birth of a puzzle.
Pulsars:
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Pulsars are rotating neutron stars observed to have pulses of radiation at very
regular intervals that typically range
from milliseconds to seconds.
Features:
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Pulsars have very strong magnetic fields, which funnel jets of particles out
along the two magnetic poles.
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These accelerated particles produce very powerful beams of light.
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Often, the magnetic field is not aligned
with the spin axis, so those beams of particles and light are swept around as
the star rotates.
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When the beam crosses our line of sight,
we see a pulse; in other words, we see pulsars turn on and off as the beam
sweeps over Earth.
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Pulsar
masses range between 1.18 and 1.97 times that of the Sun, but most pulsars have
a mass 1.35 times that of the Sun.
Neutron
Star:
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It is an extremely dense and compact celestial object that forms when a massive
star runs out of fuel and collapses under its own gravity.
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The very central region of the star, the
core, collapses, crushing together every proton and electron into a neutron.
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If the core of the collapsing star is
between about 1 and 3 solar masses, these newly-created neutrons can stop the
collapse, leaving behind a neutron star. (Stars with higher masses will
continue to collapse into stellar-mass black holes.)
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Since neutron stars began their existence as stars, they are scattered
throughout the galaxy in the same places where we find stars.
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Like stars, they can be found by
themselves or in binary systems with a companion.