What is a Pulsar?
You may well ask. In fact, all of our parents have, as well as those of our friends who deign to take an interest in physics. For those with some technical background, the Princeton physics department offers an explanation. For the rest of you, we will attempt to explain it in lay terms. A Star is Born… and then it dies. Well, you needn’t look so surprised. Everything that can be born can die. We won’t get into the birth here, as it’s irrelevant to the definition of a pulsar and you can find a perfectly good explanation, with a lovely picture, at NASA. So, a star is born. Its fire is sustained by fusing hydrogen atoms (this gives off a tremendous amount of energy). Eventually, it runs out of hydrogen, and moves onto helium fusion, and then so on down the periodic table. However, fusion of iron and any heavier elements requires energy input, not output, so once a star’s core is reduced to iron, unless it happens to have a humongous power generator on hand and some very skilled technic
A pulsar is a rapidly rotating neutron star which emits large amounts of electromagnetic radiation (light, x-rays, radio waves, etc.) and particle jets. A neutron star is what is left over when a star 4 – 8 times the mass of our sun burns up most of its fuel and explodes in a supernova. The outer layers of the star shoot outwards rapidly, while the stellar core collapses to a sphere approximately 20 km in diameter. Some neutron stars do not rotate very rapidly but those that do are known as pulsars. Suns more massive than 8 times the mass of our sun collapse to form black holes, which emit very little radiation because their gravity well is so deep that nothing can escape from it. Suns less than 4 times the mass of our sun turn into Red Giants and then brown dwarfs, without collapsing into a neutron star. But those suns that do collapse into neutron stars release a massive amount of energy in the process, due to the sheer energy of the collapsing matter. Sometimes a small initial rotat
A pulsar is a highly magnetized, rapidly rotating neutron star. Weighing more than our Sun, yet only 20 km in diameter, these incredibly dense objects produce radio beams that sweep the sky like a lighthouse. Since their discovery in 1967, over 1700 pulsars have been found, and they provide a wealth of information about neutron star physics, general relativity, the Galactic gravitational potential and magnetic field, the interstellar medium, celestial mechanics, planetary physics and even cosmology. Here at WVU, we use pulsars to carry out research into many of these areas using a wide variety of telescopes in different areas of the electromagnetic spectrum. Most of the stars we see in the night sky are in equilibrium, resisting the relentless pressure to collapse under their own gravity with radiation pressure generated from nuclear reactions within their cores. About once every second in the Universe, and once a century in our Galaxy, a star several times the mass of the Sun runs has
A pulsar is a highly magnetised neutron star, with a radius of 10-15 km, having somewhat greater mass than the Sun which has a radius of approximately 1 million km. Radiation is beamed out along the magnetic poles and pulses of radiation are received as the beam crosses the Earth, in the same manner as the beam from a lighthouse causes flashes. Being enormous cosmic flywheels with a tick attached, they make some of the best clocks known to mankind. These sounds directly correspond to the radio-waves emitted by the brightest pulsars in the sky as received by some of the largest radio telescopes in the world. To listen to the pulses of a radio pulsar, click on its arrow icon.
