An international team led by Indian astronomers has discovered a pair of dead stars, known as white dwarfs, spiraling toward each other at a record-breaking speed. The system, designated eRASSU J060839.5-704014 (eRASSU J0608), was first detected by the SRG eROSITA all-sky survey and has now been studied in detail using observations from the Einstein Probe, a Chinese-led mission.
The research, led by Rahul Sharma and Professor Chandreyee Maitra, found that the two white dwarfs are orbiting each other with a period of just 3.8 hours, and their orbital period is shrinking by about 1.2 milliseconds per year. This rapid decay is the fastest ever observed for a binary white dwarf system, and it provides strong evidence for the emission of gravitational waves, as predicted by Einstein's theory of general relativity.
The system is located about 1,400 light-years away in the constellation of Reticulum. The team used X-ray and optical observations to characterize the pair, which are likely to merge in about 100,000 years, potentially leading to a supernova explosion.
This discovery not only sets a new record for orbital decay but also offers a unique laboratory to study gravitational wave physics and the evolution of binary star systems. The findings have been published in the journal Nature Astronomy.
