Astronomers were already able to see various extremely distant galaxies, but being able to spot individual stars is understandably more difficult unless they go supernova. However, sometimes, cosmic alignment works in their favour. Researchers who are using the Hubble space telescope data were able to spot spotted Icarus (also known as MACS J1149+2223 Lensed Star 1). Icarus is a blue supergiant whose light was emitted when it was 9 billion light years away from the Earth — more than 100 times farther as compared to the previous record-setter. The researchers were able to capture the star thanks to a rare, ideal gravitational lensing effect where the light of the star was magnified not only by the gravity of an in-between galaxy cluster that is 5 billion light years from Earth but also by a star that is inside that cluster. The lensing magnified Icarus 2,000 times.
Observers had been keeping an eye on the cluster ever since 2014 when they have detected a supernova that turned out to be present in a galaxy that is 9 billion light-years away. They realised that Icarus was present in April 2016, when a point of light that was near the supernova appeared to change brightness.
However, people should not get too attached to this new discovery. With the kind of distance, Icarus has already turned into a black hole or a neutron star. However, the discoveries are still advancing science in ways that people might not expect. As noted by the Guardian, the study on Icarus ruled out a theory that dark matter consists of black holes as if that had been the case, they would have brightened Icarus even more. It just proves that humans can detect more than just the brightest and largest celestial objects at these kinds of distances.