Supernova remnant
A supernova remnant (Engl. Supernova remnant , shortly SNR) is an emission nebula formed by a supernova occurs.
99% of the energy released by a supernova is emitted as neutrino radiation, which hardly interacts with matter; the remaining percent greatly accelerates the outer layers of the precursor star. The resulting supersonic shock wave made of stellar material propagates far into the interstellar medium at an almost constant speed of around 10,000 km / s and heats it up to 10 7 to 10 8 K. In this free expansion phase, which lasts about 200 years, the SNR reaches a size of about 10 light years . This is followed by a radiation phase lasting around 10,000 years.
Supernova remnants often have a shell structure, since further shock waves can be triggered by material falling on the compact remnant. These further outbreaks can occur centuries later.
Perhaps the most famous and closely watched remnant is Supernova 1987A , which came from a supernova in the Large Magellanic Cloud . Other well known supernova remnants are
- 3C10 as a relic of the Brahean supernova , named after Tycho Brahe , who recorded the brightness of this explosion in 1572;
- Kepler's SNR ( Supernova 1604 ).
In contrast, the Crab Nebula , the remnant of Supernova 1054 , is not actually a supernova remnant. So far it has not been possible to detect the envelope in the radio range that was ejected during the supernova outbreak. The Crab Nebula is a pulsar wind nebula in which the matter is torn out of the neutron star by electromagnetic forces and accelerated to almost the speed of light .
See also
Web links
- SNR Catalog (DA Green Cambridge University)
- NASA: Introduction to Supernova Remnants.
- Supernova Remnant ( Memento from May 27, 2011 in the Internet Archive ) ( UOttawa )
- Afterlife of a supernova
Individual evidence
- ^ DA Frail, NE Kassim, TJ Cornwell and WM Goss: Does the Crab Have a Shell? In: The Astrophysical Journal . tape 454 , 1995, pp. L129-L132 , doi : 10.1086 / 309794 .
- ^ Walter Lewin , Michael van der Klies: Compact Stellar X-ray Sources (Cambridge Astrophysics) . Cambridge University Press, Cambridge 2010, ISBN 978-0-521-15806-0 , pp. 323 .