Beccata supernova neonata!

[lowenz]

Era ora

http://sciencenow.sciencemag.org/cgi...08/521/2?rss=1

In a stroke of unprecedented good luck, an international team of astronomers has caught a stellar explosion called supernova at the very beginning of the blast. The observation confirms several long-held assumptions about supernovae and could provide deeper insights into the workings of these cosmic firecrackers. It also could motivate scientists to push for new instruments that can catch other stars at the moment they explode.

Although the spectacular deaths of massive stars have been well-studied, astronomers have never been able to observe one any sooner than a few days after its beginning. Consequently, mysteries have remained about a supernova's earliest moments. The problem has been that predicting exactly when a star will go supernova is nearly impossible. And even if astronomers have some inkling that an explosion is imminent, they still must arrange observing time or frantically search for an available telescope in proper position.

The supernova called 2008D neatly and surprisingly solved such problems for its discoverers, led by astrophysicist Alicia Soderberg of Princeton University. On 9 January, she and her colleagues were using the x-ray telescope aboard NASA's Swift spacecraft to observe a month-old supernova called 2007uy, located in a galaxy called NGC 2770, nearly 90 million light-years away. Suddenly, a blinding light appeared elsewhere in the galaxy, and Soderberg and her colleagues immediately recognized it was the beginning of an entirely new supernova. They contacted colleagues across the United States and seven other countries, who quickly trained eight more telescopes and arrays on the event. In Nature tomorrow, the 43-member team reports that the characteristics of the x-ray burst they detected and then studied for 30 days conforms exactly--in terms of the brightness of the radiation, its precise rate of dimming, and the speed with which debris traveled through the galaxy--to what astronomers had been assuming for decades about the shock wave of a supernova blowing apart the outer layers of a star. They detected no gamma rays associated with the blast, confirming another prediction of the models.

"It's the first time we have seen the signature of the shock wave coming from the core collapse," says astrophysicist and co-author Neil Gehrels of NASA's Goddard Space Flight Center in Greenbelt, Maryland. Gehrels, leader of the Swift science team, says that the most important observations of the x-ray burst were over "in an hour," but that it's important to continue following the supernova to learn more about the star. He says this experience likely will "drive the development of wide-field x-ray telescopes," which will increase the chances of discovering more supernovae at the moment of explosion.

"We now have a direct observation of a star at the moment of its death," says astronomer Robert Quimby of the California Institute of Technology in Pasadena. Although the observation didn't produce any huge surprises, he says, it should aid future studies on the origins of supernovae. Of more immediate value, says astrophysicist Stanford Woosley of the University of California, Santa Cruz, the pattern of x-rays emitted by the supernova might tell researchers more precisely what sort of signatures to look for in gravitational waves and elusive neutrinos, both of which are associated with supernovae.

[hibone]

guardoni... basta con le paparazzate!

ps... ma filmarla?!

[Jo3]

Speriamo che stavolta gli orologi atomici dei rilevatori di neutrini li abbiano sincronizzati a dovere !