| Crab Nebula: supernova remnant and pulsar (infrared view) | 29/08/1999 | ||
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The
Crab Nebula is the remnant of a supernova explosion that was seen on Earth
in 1054 AD. It is 6000 light years from Earth. At the center of the bright
nebula is a rapidly spinning neutron star, or pulsar that emits pulses of
radiation 30 times a second. Constellation: Taurus Optical view X-ray view Radio view |
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| Image Credit: W M Keck Observatory. | |||
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| The
Crab Nebula consists of a pulsar, a rapidly rotating neutron star at the
center, surrounded by a bright diffuse nebula. The nebula, which is about
six light years across, is expanding outward at 3 million miles per hour.
The filamentary system visible in the optical images is near the outer boundary
of this expansion. Both the nebula and the pulsar are bright sources of
radiation in all wavelengths.
The radiation we observe from the Crab Nebula is produced mainly by high-energy particles accelerated by the neutron star. These energetic particles, which near the neutron star are thought to include anti-matter positrons as well as electrons, spiral around magnetic field lines in the nebula and give off radiation by the "synchrotron" process. |
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The infrared radiation comes from electrons with energies lower than those producing the optical light. Additional infrared radiation comes from dust grains mixed in with the hot gas in the filaments. | |
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