A recent study by researchers from University College London and the University of Potsdam has revealed that two massive stars in the Small Magellanic Cloud, a neighboring dwarf galaxy, are in a binary system that will evolve into black holes. The smaller star, 32 times the mass of the Sun, is losing mass to its larger companion, which has 55 times the Sun’s mass. Observations indicate that these stars are in partial contact and exchange material, orbiting each other every three days. The study suggests that within a couple of million years, the smaller star will collapse into a black hole, followed shortly by its companion, after which they will orbit each other for billions of years before merging. This collision is expected to produce gravitational waves, detectable by instruments on Earth. The researchers used spectroscopic analysis from ground and space telescopes to study the stars’ properties. The unique low-metallicity conditions in the Small Magellanic Cloud, akin to those in the early universe, provide insights into black hole formation. The study highlights the significance of this system in understanding the evolution of massive binary stars and the mechanics behind black hole mergers. This binary star system is the most massive contact binary observed to date.
