New study finds evidence of cosmic explosions with missing black holes

An international team led by Monash Univer­sity has uncovered evidence of a rare form of exploding star, helping to shed light on one of the most cataclysmic events in the Universe. At the end of their lives, most massive stars collapse into black holes — objects with gravity so strong that not even light can escape.

Some very massive stars, however, are expected to become so hot that they are blown apart in a pair-instability supernova – an explosion so intense that the star is completely disrupted, leaving behind no black hole.

First predicted in the 1960s, pair-instability supernovae are challenging to distinguish from more common stellar explosions that leave behind black holes.

In a study published in Nature, researchers found that by using gravitational waves – ripples in the fabric of spacetime detected by the LIGO-Virgo-KAGRA observatory network – they were able to measure the properties of black holes and found a “forbidden range” of black-hole masses.

Black holes with masses more than 45 times the mass of the sun are rare because the stars that might otherwise have made them exploded in pair-instability supernovae.