I'm not sure why Marnie sent this. > Sent from my mobile. > them," says Rivinius. Baade adds that finding a black hole in a > triple system so close by indicates that we are seeing just "the > tip of an exciting iceberg." > > Already, astronomers believe their discovery could shine some light > on a second system. "We realised that another system, called LB-1, > may also be such a triple, though we'd need more observations to > say for sure," says Marianne Heida, a postdoctoral fellow at ESO > and co-author of the paper. "LB-1 is a bit further away from Earth > but still pretty close in astronomical terms, so that means that > probably many more of these systems exist. By finding and studying > them we can learn a lot about the formation and evolution of those > rare stars that begin their lives with more than about 8 times the > mass of the Sun and end them in a supernova explosion that leaves > behind a black hole." > > The discoveries of these triple systems with an inner pair and a > distant star could also provide clues about the violent cosmic > mergers that release gravitational waves powerful enough to be > detected on Earth. Some astronomers believe that the mergers can > happen in systems with a similar configuration to HR 6819 or LB-1, > but where the inner pair is made up of two black holes or of a > black hole and a neutron star. The distant outer object can > gravitationally impact the inner pair in such a way that it > triggers a merger and the release of gravitational waves. Although > HR 6819 and LB-1 have only one black hole and no neutron stars, > these systems could help scientists understand how stellar > collisions can happen in triple star systems. > > This research was presented in the paper "A naked-eye triple system > with a nonaccreting black hole in the inner binary", published > today in Astronomy & Astrophysics. > > More information: "A naked-eye triple system with a nonaccreting > black hole in the inner binary", Astronomy & Astrophysics (2020). > DOI: 10.1051/0004-6361/2020380