An X-Ray image of a supernova remnant and its central neutron star
Click on image for full size
ROSAT satellite image courtesy of NASA
Neutron Stars are the end point of a massive star's life. When a really
massive star runs out of nuclear fuel in its core the core begins to
collapse under gravity. When the core collapses the entire star collapses.
The surface of the star falls down unti l it hits the now incredibly dense
core. It then rebounds off the core and blows apart in a type IIa supernova
. The core tries to
resist gravity with the quantum mechanical electron pressures that hold white dwarfs
together. But that will not
work here; gravity is just too strong because the density is very very
high. Electrons in orbit of protons in normal atoms collapse into the
and form neutrons. Now the star is almost completely made of
neutrons and their quantum mechanical pressures are enough to resist
A typical neutron star is the size of a small city, only 10
Kilometers in diameter but it may have the mass of as many as three suns.
It is quite dense. One spoonful of neutron star material on Earth would
weigh as much as all the cars on Earth put together.
Some neutron stars spin quite rapidly and have very strong magnetic
fields. If the magnetic poles are not lined up with the star's rotation
axis then the magnetic field precesses around at an alarming rate. Charged
particles can get caught up in the magnetic fields and beam away
radiation along cones near the magnetic poles, kind of like a lighthouse
beacon. This type of neutron star is called a pulsar. Pulsars are detected
by their rapidly repeating radio signals beamed at Earth from those
charged particles trapped in the magnetic field. When they were first
discovered it was thought that they were radio signals from "Little Green
Men" from outer space. Weird.
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
White Dwarfs are the remnants of stars that were massive enough to stay alive using nuclear fusion in their cores, but not massive enough to blow apart in a Type II supernova. When stars like our own sun...more
NASA recently revealed a few of the many images that will come from its newest telescope. Since first being deployed July 23, the Chandra X Observatory has functioned perfectly. It first made a series...more
In the 1960's, the United States launched a series of satellites to look for very high energy photons, called Gamma Rays, that are produced whenever a nuclear bomb explodes. These satellites soon detected...more
Jocelyn Bell is a British astronomer who was born in 1943. She discovered pulsars in 1967. Burnell was a graduate student at Cambridge University when she discovered pulsars. Her advisor, Tony Hewish,...more
The introduction of telescopes to the study of astronomy opened up the universe, but it took some time for astronomers to realize how vast the universe could be. Telescopes revealed that our night sky...more
Neutron Stars are the end point of a massive star's life. When a really massive star runs out of nuclear fuel in its core the core begins to collapse under gravity. When the core collapses the entire star...more
Spiral galaxies may remind you of pinwheels turning slowly as though in some intergalactic breeze. They are rotating disks of gas, dust and stars. Through a telescope or binoculars, the bright nucleus...more