Pulsars

     
    If someone asked you what a pulsar is, you might have a idea, but, if you wanted a good definition of a pulsar a would read this post. You also probably know it's a star in space, but we will discuss details.


Basic Definition

A pulsar is a rapidly rotating-neutron star that emits brief "pulses" of energy, usually radio waves.
Discovery
Pulsars started at Cambridge university with Antony Hewish and his students built a radio telescope to study a scintillation effect on radio sources caused by clouds of electrons in the solar wind. In 1967, it quickly recorded a signal from a unexpected source. Jocelyn Bell Burnell notice a strong sparkling effect   opposite the sun, when the affect was strong, and should have been weak.An improved recorder was installed, the signals were received again as a series of sharp pulses with intervals of about a second. In late 1968, it was clear Antony Hewish and his students had discovered a rotating neutron star, a remnant of a supernova, which we now called a pulsar.

Binary Pulsars
A binary pulsar is two stars that rotate each other and one of them is a neutron star. This was discovered by  Russell A. Hulse and Joseph H. Taylor, who received and shared a physics Nobel Prize in 1993. With this, they tested the general theory of relativity. Several dozen binary pulsars are known in space. This bursting pulsar, another class of pulsars, is currently the strongest source of X rays and gamma rays in the sky.


Pulsars have a strong magnetic field and a lot of plasma, which means it has a large source of radio waves. The electrons (which have lots of energy) of the plasma orbit (,or spiral)  around the magnetic field and emit radio waves and other types of waves from the electromagnetic spectrum.


Vocabulary


Synchrotron Radiation - Electromagnetic radiation emitted by a charged particle (normally an electron) 
moving in a magnetic field at a velocity very close to that of light.
Gyrosynchrotron Radiation - Electromagnetic radiation emitted by a charged particle moving in a magnetic field at an appreciable fraction of the speed of light, this is similar to synchrotron radiation.
Cyclotron Radiation - Electromagnetic radiation emitted by a charged particle circling in a magnetic field substantially below the speed of light, and is also similar to gyrosynchrotron radiation.
Rotation-powered pulsars, where the loss of rotational energy of the star provides the power.
Acceration-powered pulsars - where the gravitation potienal energy of accreted matter is the power source (producing X-rays that are observable from the Earth).
Ratation-powered pulsars - Where the loss of rotational energy of the star provides the power.




More
This synchroton radiation is highly directional. Since 1968, more than 700 pulsars have been observed.The first pulsar with planets is currently SR BL257+12.