Stellar behemoth self-destructs in a Type IIb supernova
Our Sun may seem pretty impressive: 330,000 times as massive as Earth, it accounts for 99.86 percent of the Solar System's total mass; it generates about 400 trillion trillion watts of power per second; and it has a surface temperature of about 10,000 degrees Celsius. Yet for a star, it's a lightweight.
The real cosmic behemoths are Wolf-Rayet stars, which are more than 20 times as massive as the Sun and at least five times as hot. Because these stars are relatively rare and often obscured, scientists don't know much about how they form, live and die. But this is changing, thanks to an innovative sky survey called the intermediate Palomar Transient Factory (iPTF), which uses resources at the National Energy Research Scientific Computing Center (NERSC) and Energy Sciences Network (ESnet), both located at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), to expose fleeting cosmic events such as supernovae.
For the first time ever, scientists have direct confirmation that a Wolf-Rayet star -- sitting 360 million light years away in the Bootes constellation -- died in a violent explosion known as a Type IIb supernova. Using the iPTF pipeline, researchers at Israel's Weizmann Institute of Science led by Avishay Gal-Yam caught supernova SN 2013cu within hours of its explosion. They then triggered ground- and space-based telescopes to observe the event approximately 5.7 hours and 15 hours after it self-destructed. These observations are providing valuable insights into the life and death of the progenitor Wolf-Rayet.
"Newly developed observational capabilities now enable us to study exploding stars in ways we could only dream of before. We are moving towards real-time studies of supernovae," says Gal-Yam, an astrophysicist in the Weizmann Institute's Department of Particle Physics and Astrophysics. He is also the lead author of a recently published Nature paper on this finding.
"This is the smoking gun. For the first time, we can directly point to an observation and say that this type of Wolf-Rayet star leads to this kind of Type IIb supernova," says Peter Nugent, who heads Berkeley Lab's Computational Cosmology Center (C3) and leads the Berkeley contingent of the iPTF collaboration.
more
http://www.sciencedaily.com/releases/2014/05/140521133520.htm
= new reply since forum marked as read
