But 708 didn’t go quietly into the night. Instead, scientists believe the feeding frenzy ended in a supernova explosion that catapulted the ravaged remains with such force it’s leaving the galaxy. Fast.
A new study shows that the star, classified as a hot subdwarf, is blasting through the Milky Way at about 750 miles per second, faster than any other star in the galaxy.
It's also the only one of about 20 similar runaways slingshot away by a supernova explosion, research published in this week’s Science shows.
The other stars traveling fast enough to leave the Milky Way’s gravitational fist are believed to have been booted by the supermassive black hole lurking in the center of the galaxy.
“US 708 does not come from the galactic center. We don't know any other supermassive black hole in our galaxy. One needs one of those. A smaller, stellar-mass black hole formed by the collapse of a massive star can't do the job,” astronomer Stephan Geier, with the European Southern Observatory, told Discovery News.
“It’s only one object so far,” he added, but if others can be found, scientists would have a way to directly study supernova.
US 708 will leave the Milky Way in roughly 25 million years, cooling over time and transforming into a white dwarf star.
Astronomers first found the star in 2005, but at that time could only determine the velocity, not the rapid spin, which later became evidence for its donor past.
In 2009, theorists developed computer models showing that stars could reach escape velocity by a supernova blasts.
“This motivated us to have a closer look at US 708 again,” Geier said.
Read more at Discovery News
No comments:
Post a Comment