X-rays suggest the merger didn’t create a supersized version of the stellar remnants
The first observed smashup of two stellar remnants known as neutron stars probably forged the least massive black hole yet discovered, researchers report in the June 1 Astrophysical Journal Letters.
This cosmic collision, observed in August 2017, took the astronomical community by storm and offered insights into the origins of precious metals and the mysterious dark energy that fuels the expansion of the universe (SN: 11/11/17, p. 6). Ever since, astronomers have wondered what became of the two neutron stars once they’d merged. This enigmatic amalgamation of dead stars — weighing about 2.7 times the mass of the sun — was suspected to be either a neutron star heftier than any yet discovered or the most lightweight black hole. The previous record-holder for lightest black hole was