Cannibal star creates rare white dwarf

With a new astronomical discovery, researchers have been able to prove the formation of a class of stars that were barely discovered before. in one binary star system diss scholars De Havard and Smithsonian Astrophysics Center very rare white dwarf Found, its existence was previously unjustified.

When a star dies, there is a possibility 97 percent white dwarf; These are the little things with the very High intensity and temperature, but low gloss. However, on very rare occasions, a dead star becomes a layer white dwarf ELM (very low mass). These stars are less than a third the mass of the Sun.

Older than existence

But they pose a problem to researchers. If the calculations of star evolution since the Big Bang are correct, then all white dwarfs should have at least ELM 13.8 billion years be old This would make some older than the universe itself which is physically impossible.

“The universe is not old enough for these stars to form through natural evolution,” he says. Kareem El-Badry who leads the search, in the current situation. So astronomers hypothesized that such ELMs could only form in binary star systems.

Cannibal star speeds up ‘aging process’

The two stars revolve around their center of gravity. The star eats little by little of its companion until only a white dwarf remains. This could significantly shorten the time period of 13.8 billion years.

Until now it has been possible to observe ELMs and binary star systems with ordinary white dwarfs. However, the moment when a white dwarf is currently in the process of transforming into an ELM, is far from over. new data from The European Space Agency’s Gaia Space Telescope and the Zwicky Transit Facility Caltech has identified 50 candidates who could become ELM.

White dwarf in the shape of an egg

21 These candidates have now been screened. “100 percent of them were in the pre-ELM that we were looking at,” Al-Baldari says. They were slightly more inflated than ELMs and were in binary star systems known as catastrophic variable is set. Here the companion star’s gravity is so strong that the white dwarf turns into an egg or falls.

13 of the stars selected They still lose mass to their partner. The remaining eight samples no longer lost mass and were hotter than any other catastrophic variables found so far. This discovery could fill a gap in the theory of stellar evolution. The results are in the specialized journal Monthly Notices of the Royal Astronomical Society Back.