A pair of hot, young stars, circling each other like boxers looking for an opening, are the new heavyweight champions of the cosmos, astronomers said Wednesday.
Each of the two stars is 80 times heavier than the sun, making them the heaviest stars ever measured, according to scientists at the Harvard-Smithsonian Center for Astrophysics.
The two-star system, known officially as WR 20a, was singled out as particularly interesting only weeks ago by European researchers headed by Gregor Rauw of Belgium.
They are both Wolf-Rayet stars, extremely rare hot stars that live fast and die young. They orbit each other every 3.7 days, and they are so close together that each star's gravitational pull distorts the other's shape.
Observations made at the Las Campanas Observatory in Chile confirmed the two stars' heavyweight status.
The two-star system is located about 20,000 light-years away in the constellation Carina. A light-year is about 6 trillion miles (10 trillion kilometers), the distance light travels in a year.
Astronomer Alceste Bonanos of the Harvard-Smithsonian Center for Astrophysics said these two are already 2 million to 3 million years old. Our sun is about 4.5 billion years old.
"In another few million years, whichever one is slightly more massive will undergo core collapse and blast off its outer layers," Bonanos said in a statement. "The companion star likely will survive despite its nearness, at least until it goes supernova sometime later."
Other stars are suspected of having enough material to make more than 100 suns, but their masses have not been accurately determined. WR 20a is the most massive known binary system where both stars have precisely determined masses.
