SN1987A, the supernova exploded in the Large Magellanic Cloud (at about 170000 light years of distance) on February 23rd 1987, was an iconic event for the study of supernovae and supernova remnants. In fact, it is the only case where it was possible to observe (with telescopes) the explosion and to follow with periodic observations the evolution of the supernova
LBV (Luminous Blue Variable) stars are massive and unstable stars characterized by large mass-lost due to intense stellar winds and aperiodic bursts. Due to their instability, LBV stars are also variable, with quasi-periodic oscillations of their luminosity of the order of 0.5-2 magnitudes. Typical examples of this class of stars are: the supergiant S Doradus in the Large Magellanic Clouds,
Energetic particles, called “cosmic rays”, constantly rain down on our planet. Thanks to several years of theoretical studies and observations, we know that these particles can be accelerated by shocks propagating in certain astrophysical environments. The classical example of such environment are the supernovae remnants, which are expanding clouds created by supernova explosions, which are often interacting with surrounding material.
Supernova explosions are sorted into two categories: The thermonuclear explosions triggered by white dwarfs in close binary systems (type Ia) and those triggered by the gravitational collapse of the core of massive stars (type Ib/c and II). Because of the paucity of known supernova remnants younger than 1000 years, astronomers developed several models describing the evolution of supernova remnants to
Supernova remnants are nebulae created by supernova explosions. These expanding clouds are formed by the interstellar medium shocked and heated up by the expanding shock produced by the explosion, and the knots of material launched by the exploding star, called ejecta. These ejecta are located behind the expanding shock, traveling with lower velocity, and they are heated up by the reverse shock:
Supernove explosions are repeatedly observed in distant galaxies, which lie at such large distances that it is impossible for us to resolve the geometry of the ejected material and its interaction with the surrounding interstellar and circumstellar clouds. With the only exception of SN 1978A, in the Milky Way and in the nearby galaxies (namely the Magellanic Clouds), we did
At the end of their evolution, stars with a final mass larger than 8 solar masses (“final mass” because massive stars lose a large fraction of their mass as stellar winds during their evolution) explode as Core-Collapse Supernovae, e.g. triggered by the collapse of their nucleus. Two objects are produced by such explosions: the supernova remnant formed by the ejected
di Mario Giuseppe Guarcello ( segui mguarce) Lo studio dei resti di supernova, nubi formate dalle esplosioni di supernova, sono oggetti di grande interesse scientifico. Queste nebulose, infatti, non sono semplicemente il residuo di uno dei fenomeni più violenti che avvengono nell’Universo (un’esplosione di supernova dal collasso di una stella massiva, ossia le “core-collapse supernovae”, produce un’energia pari
Supernova remnants, i.e. the remnant of supernovae explosions, are among the most interesting astronomical objects. In fact, they are not only produced by one of the most violent phenomenon occurring in the Universe (the explosion of a supernova from the collapse of the core of a massive star, i.e. a “core-collapse supernova”, which emits the same energy of 1033 atomic
