Learn about the studies and researches after the supernova Magellan was discovered.
Read the full transcript »

Where the Discovery of the Magellan Lead to On the night of February the 23, 1987 at the Las Campanas Observatory in Southern Chile Ian Shelton photographed the large Magellanic Cloud. As he developed his plates, he saw a bright object that was not on the previous plates. He thought it was only a flaw but he walked outside to check it. In the sky, he saw a star he had never seen before, an object appearing so suddenly he knew it must be a supernova. Ian Shelton telegraphed his discovery to the International Astrophysical Union. Using global computer networks, the IAU announced to the world the discovery of one of the biggest cataclysms imaginable in the universe designated SN 1987A, the supernova is located in the tarantula nebulae in the large Magellanic Cloud, the galaxy nearest to ours. Even though the supernova is 170,000 light years away, it's the closest supernova since Johannes Kepler saw one in 1604 in the Milky Way. It's a rare experience for a supernova to be visible to the naked eye. Although in 1054, the Crab Supernova was visible even in daylight. For its part, supernova 1987A was clearly visible at night. It was once a faint star. Although in fact a blue super giant about 15 times the mass of our sun. But a star is always subject to its own gravity. When its hydrogen becomes depleted, gravity will take control and the core of the star will contract and get hotter. The supernova will occur at the end of a massive star’s lifetime when its nuclear fuel is exhausted and it is no longer supported by the release of nuclear energy. If the star’s ion core is massive enough, then it will collapse. In this giant nucleus, the protons and electrons of the ion are so close to each other that they combine to form neutrons. Thus, the core of the collapsing star becomes a giant ball of neutrons, a neutron star. If a collapsing star were big enough, its gravitational force would overcome even the forces that hold atomic nuclei together and the core would become a black hole. But if the star is not massive enough to form a black hole, it reaches a point where its core cannot collapse any further. At this so called point of maximum scrunch, the core bounces back and blows the rest of the star out into space with an explosive energy more than 10 times the lifetime output of our sun. This explosion is called a supernova. The energy emitted by a supernova is primarily composed of neutrinos, particles that very rarely interact will matter. Neutrinos can be detected in huge tanks of purified water buried in mines in Japan and the United States. Three hours before the first optical observations of the supernova were made, these detectors noted neutrino emissions somewhere in the direction of the large Magellanic Cloud. The neutrinos interacted with the purified water and caused flashes of light which registered on the photodetectors on the tanks. These detections were not discovered until later but they confirmed theories about how a supernova explodes. The energy of the star creates a superstrong shockwave that runs outward towards the star’s surface. When the shockwave reaches the star’s surface, it very quickly hits the surface layers and brightens them. This is the moment when distant observers first learned that a supernova is exploding. In the year following the supernova, several experiments measured extensive gamma ray radiation. The data was gathered by NASA’s Solar Maximum Mission already in orbit around the earth, an instrument lighted balloons which were launched in Australia. Japan launched the Ginga Satellite which detected some of the scattered x-rays. NASA’s rocket experiments launched from Australia also experienced radiation over several wavelengths. Now the rocket borne missions and the International Ultraviolet Explorer observed the ultraviolet spectrum. These measurements revealed information about the density and temperature of the supernova and the formation of molecules surrounding the supernova and in nearby spac

Advertisement
Advertisement
Advertisement