SN 1987A
3 like
3085 may
168,000 light years
Large Magellanic Cloud
Sanduleak -69 ° 202a
B3 Supergiant
Type II -P
24 2 1987 ( 23:00 UTC)
SN 1987A is the erdnächste supernova that was observed since the supernova 1604. It was discovered on 24 February 1987, took place in the Large Magellanic Cloud ( LMC ). This is about 48,000 ± 5,000 parsecs away, which corresponds to about 157,000 ± 16,000 light years.
Progenitor star
SN 1987A was the first supernova, in which one could identify the predecessor. The one with his core collapse explosion triggering star was part of a system of three suns. He was classified before his downfall of Nicholas Sanduleak in a directory of hot blue stars in the LMC. The collapsar is with Sanduleak -69 ° 202 (short: Sk -69 202 ) called and had about 17 solar masses. Sk -69 202 ended his life as so-called Blue supergiant. His age at the time of the explosion is estimated to be "only" about 20 million years. During this short life span he verfeuerte its energy supply compared to our Sun, which is already about 5 billion years old, so fast many times.
Based on theoretical considerations, it is assumed that the core collapse of Sk -69 202 led to the formation of a neutron star. Neither in the field of X-rays, radio emission even in the optical domain, a radiation source at the location of the progenitor star could be found. The search for a pulsed source, characteristic of a pulsar was not successful. There are numerous hypotheses regarding the lack of a detectable neutron star:
- Defaulted matter has led to the conversion of the neutron star into a black hole.
- A cold cloud of dust prevents the detection of the neutron star due to absorption.
- Instead of a neutron star to a quark star formed.
The remains of the supernova 1987A are one of the most studied astronomical objects today.
Neutrino emission
Three hours before the visible light reached Earth, a strong neutrino emission of various neutrino observatories were found that were actually operated to study the neutrino oscillation and the search for proton decay. This was the first neutrino measurement on a supernova, confirming theoretical models according to which a large part of the energy of a supernova is radiated in the form of neutrinos. Since the neutrino detectors were not sensitive enough, we were unable to detect the full energy spectrum. In addition, since only an observatory had synchronizes the time of his knife detector with an atomic clock and especially the event rates were far too low, could not be detected by comparing the time stamps of the observatories, if the neutrinos were traveling at light speed or slower. Were detected in the Kamiokande neutrino eleven, eight in Irvine Michigan Brookhaven experiment and possibly five in the Mont Blanc Underground Neutrino Observatory and five in the Baksan detector. These are to date the only proven neutrinos, which certainly come from a supernova, which in turn could be observed a few hours later with telescopes.
The neutrinos arrived before the light reached the earth, as they (ie unrestrained ) can pass through matter virtually no interaction. So they left the collapsed core and the shock wave directly after the event - the light of the supernova was visible only when the explosion had reached the stellar surface, which was the case for about three hours later.