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
Stars in several star forming regions are observed with a spread in age. This support the idea that star formation is a “slow” process which can propagate across a molecular cloud over million of years (as suggested, for instance, by the Palla & Stahler 2000 study), while several authors have instead suggested that star formation is a “fast” process (e.g.
The life cycle of very massive stars ends in supernovae explosions. During these violent phenomena, an amount of energy similar to that produced by the Sun during its entire lifetime,more than 10 billion years long, is released in few seconds. Besides, the atmosphere of the exploding star (the progenitor star) is ejected with a velocity in excess of 1000 km/sec.
L’astronoma Beate Stelzer dell’Osservatorio Astronomico di Palermo è autrice dell’articolo “X-ray orbital modulation of a white dwarf accreting from an L dwarf” pubblicato su Astronomy & Astrophysics. Nell’articolo sono analizzati i dati ai raggi X ottenuti da osservazioni con il satellite XMM/Newton del sistema binario SDSS J121209.31+013627.7, composto da una nana bianca ed una nana bruna. Nello studio è riportata la
