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Integral in brief Integral overviewIntegral factsheetA truly international missionAbout Integral The spacecraftThe launcherThe launch site - BaikonurThe journey Integral's mission Multimedia Image galleryPre-launch images, Sept 2002Pre-launch images, October 2002Video gallery3D Flash 'model'Make a model
| | | | | | | | | A stellar black hole can be seen when it rips a companion star to pieces | |
The densest objects in the Universe
When a massive star explodes, not all the material is ejected into space.
Some of it collapses into an extremely compact object known as a neutron
star, inside which gravitational forces crush protons and electrons together,
turning them into particles known as neutrons.
A neutron star contains a few solar masses of material squeezed into a radius of only 20 km. This
means the matter is so compressed that a thimble full of it would weigh millions
of tonnes on Earth. Fast-spinning neutron stars, whose radio emissions
seem to pulse on and off, are called pulsars.
Beyond the mass limit of a neutron star - about three solar masses - gravity
becomes overwhelming and collapses the star even further, creating a black
hole. These are perhaps the strangest objects in the Universe because nothing,
not even light, can escape from inside a black hole. So, the presence of
a black hole can only be inferred by its effect on surrounding celestial
objects and other interstellar material.
| | A neutron star | |
Virtually all types of compact objects are significant sources of high-energy
emission because of the enormous gravitational fields they tend to generate.
Gravitational fields can accelerate particles in the vicinity to extreme velocities,
which then emit gamma rays and X-rays.
Integral will capture images of the high-energy emission from such compact
objects with unprecedented detail, allowing astronomers a clearer look than ever before at these enigmatic objects.
Last update: 15 October 2002 | |
| | ESA's gamma-ray astronomy mission Observations: Seeing in the gamma-ray wavelengthsObservations: Seeing in X-ray wavelengthsRelated links Sci & Tech Integral pageIntegral Science Operations CentreIntegral Science Data CentreIntegral video  The densest objects in the Universe
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