Discovered the closest cosmic embrace ever seen, he is between two stars - Space & Astronomy

The tightest ‘cosmic embrace’ ever observed has been discovered: it is a pair of stars, about 3,000 light years from Earth, orbiting each other in just 51 minutes. The two stars are destined to get even closer: in about 70 million years their orbit will become 18 minutes, before starting to expand and move away. The discovery, published in the journal Nature and led by the Massachusetts Institute of Technology (MIT), also confirms a decades-old theory about the existence of these particular pairs of stars, called ‘cataclysmic variables’, capable of emitting enormous flashes of light and gravitational waves.

The newly discovered pair, known as ZTF J1813 + 4251, is made up of a star similar to our Sun, roughly the size of Jupiter, and a white dwarf – the hot, dense core of a dying star. The extremely close range allowed the white dwarf to begin stripping matter from its companion, stealing its hydrogen atmosphere and leaving only the denser and heavier helium core. The largest star is in its phase of transition from a body rich in hydrogen to one made predominantly of helium.

The researchers, led by Kevin Burdge, discovered the new system within a vast catalog of more than a billion stars observed by the Zwicky Transient Facility (Ztf), an investigation using a camera connected to a telescope at the Observatory. of Palomar in California to take high-resolution photos of large swaths of the sky. Thanks to the data obtained, the authors of the study were able to accurately measure the mass and size of the two objects, as well as their orbital period. “We were lucky to find this system”, comments Burdge, “which allowed us to answer a big question that has remained open so far”.