Thus was identified and explained, a rare event that occurred not long ago in the depths of my life
Universe: A powerful gamma ray burst, following
explosion of a star. In the multinational study, participants also
Israelis
Dr. Noah Brosh
Direct link to this page: https://www.hayadan.org.il/gamabrosh1.html
At 13:37 Israel time, on March 29, an automatic message arrived from a small American satellite whose mission is to detect and locate gamma radiation bursts in the universe.
The message was circulated among ground-based observatories associated with the satellite studies. But this time she pointed to a rare event: for the first time the mysterious bursts of radiation were linked to a supernova, the explosion of a star. Israeli scientists participate in the research project (in observation and the theoretical aspect).
Following the nuclear weapons tests, satellites were launched into space in the past to detect atomic explosions, looking for a characteristic "signature": a short and particularly strong burst of gamma radiation. The satellites had a rough localization capability. To the surprise of the operators, it turned out that they were actually measuring gamma-ray bursts from space.
The nature of gamma-ray bursts (as they are called) began to become clear only when one of the satellites discovered a burst of X-rays together with the emission of radiation in the gamma range.
A certain signature also appeared in the field of visible light, making it possible to measure the distance to the erupting body - up to billions of light years from us. This indicated the release of a huge amount of this radiation in its eruption, otherwise it would not have been visible to us.
Despite these discoveries - all from the last decade - there is no general agreement among scientists regarding the phenomenon. Many astrophysicists believe that this is the last stage in the life of a very large star. When it explodes as a supernova, the core becomes a black hole. Until now there has been no observational evidence of this.
The first observations from the new eruption yielded its exact location in the universe - with the help of X-ray observations made from an unmanned satellite, about an hour after the initial discovery. Two hours later, in optical observations from the ground made in Australia, a new light source was discovered in the sky, which matched the above location.
About five and a half hours after the discovery of the gamma radiation, in the evening, the observatory in Mitzpe Ramon also noticed the source of the light. Together with other observatories, the observations from Israel clearly defined the change of light from the mysterious body: a constant decrease in the intensity of the light, with strange "jumps".
The monitoring of the gamma-ray burst was done by Tel Aviv University researchers Avishi Gal-Yam, Eran Ofek, David Polishok and Prof. Elia Leibovitz.
Additional observations, with huge telescopes, showed that the event was relatively close to us - "only" about two billion light years. Careful tests have deciphered the spectral signature of a galaxy producing stars at an increased rate. The discovery, and its connection with the burst of gamma radiation - still needs to be clarified.
What sets this event apart from others, is the prediction, the forecast, which accurately stated that starting on April 8, astronomers will notice spectral signs from a supernova. and so it was.
The forecast is a joint work of Alvaro de Rujula from the Saran Center in Geneva, Shlomo Dado and Prof. Arnon Der of the Technion (published in "Maariv Mada" on 27.4/8.4). From XNUMX the supernova trail could actually be seen in the gamma spectrum.
The theoretical prediction of the appearance of the supernova spectrum derives from the gamma-ray burst model developed by de Rochola and Derr. In this model, the star that goes supernova spins rapidly around itself. The near-free fall of its core into the resulting black hole creates a disk, throwing very large amounts of material along the axis of the star's rotation.
Each emission of material is a "cloud" similar to the Earth and during the eruption, several such "clouds" will be emitted. The injection of the material is done at a speed close to the speed of light. If, by chance, the axis of rotation generally faces the solar system, astronomers will see a particularly strong source of radiation.
But this model is still not accepted by most scientists. The gamma-ray burst prediction re-directed the matter to him. Although the light source faded, it almost disappeared completely (beyond the scope of the telescope at Mitzpe Ramon). Huge telescopes, 10-8 meters in diameter, will continue this monitoring.
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