from - Sky & Telescope By Monica Young Edited by - Amal Udawatta New analysis has revealed 21 Sun-like stars in mutual orbit around dark objects of neutron star–like masses — rare systems that have escaped destruction by supernova. Most massive stars are born with at least one stellar sibling. But as the massive ones of these groups mature, they wreak havoc on their families. Yet astronomers have found some that have survived this tumult. Before exploding as a supernova, a massive star expands, sometimes engulfing any stellar companions. Or, even if the companion avoids being swallowed up, it may yet end up on its own: The supernova imparts a kick on the crushed core of the massive star, causing the newborn neutron star to escape the system. Many of the thousands of neutron stars known in the Milky Way are alone. But in a new analysis of data from the European Space Agency’s Gaia mission, Kareem El-Badry (Caltech) and colleagues have found 21 survivors: “dark” neutron stars in mu