Astronomers have discovered a pair of stars with such short orbits that they appear to orbit each other in just 51 minutes. The system appears to be one of a rare class of binaries known as “catastrophic variable”, in which a star similar to our Sun closely orbits a “white” dwarf, the hot and dense core of the burning star.
According to the British newspaper, “Daily Mail”, this phenomenon occurs when two stars come close to each other over billions of years, causing the white dwarf to start accumulating or devouring material from the partner star.
This process can produce huge, variable flashes of light that astronomers have believed for centuries to be the result of an unknown cataclysm.
The “catastrophic” system, located about 3,000 light-years from Earth in the constellation Hercules, has the shortest orbit of its kind to date.
It was also discovered by astronomers from the Massachusetts Institute of Technology and named ZTF J1813 + 4251.
Unlike other systems observed in the past, experts discovered this catastrophic variable when stars dimmed each other several times, allowing the team to precisely measure the properties of each star and then run simulations of what the system likely does today and how it might happen. They evolve over hundreds of stars. million years in the coming years.
This led researchers to theorize that stars are currently in transition and that the sun-like star is rotating and donating much of its hydrogen envelope to the white dwarf.
The astronomers also say that over time, the Sun-like star will eventually disintegrate into a dense, helium-rich core, and after another 70 million years, the stars will migrate closer together in an extremely short orbit of just 18 minutes before beginning to expand and drift away.
Researchers at MIT and elsewhere have predicted for centuries that such catastrophic variables would move into ultrashort orbits, but this is the first time such a transition system has been directly observed.
“This is a rare case where we discovered one of these systems during the transition from hydrogen accretion to helium accretion,” said Kevin Burdge of the MIT Department of Physics.
People expected these objects to travel in very short orbits, and it has long been debated whether they could get short enough to emit detectable gravitational waves, and this discovery confirms it.
Burdge and colleagues discovered the new system in the Zwicky Transient Facility Extensive Star Catalog (ZTF), a survey that uses a camera attached to a telescope at Palomar Observatory in California to capture high-resolution images of large bands of stars. . the sky.
The survey took more than 1,000 images of each star among the more than one billion stars in the sky, and recorded the changing brightness of each star over days, months and years.