Gaia's Precision Prediction of Microlensing Events

The ESA's Gaia Observatory has made yet another significant breakthrough, this time in the prediction of microlensing events. Using data from Gaia's third data release (DR3), a team of researchers led by the Chinese Academy of Sciences (CAS) has predicted 4,500 microlensing events, 1,664 of which are unlike any we have seen. These events will allow astronomers to conduct lucrative research into distant star systems, exoplanets, and other celestial objects.

Microlensing is a phenomenon that occurs when light from a background source is deflected and amplified by a foreground object. This can happen when a star or other massive object passes in front of a distant star or galaxy. The gravitational pull of the foreground object bends the light from the background source, causing it to appear brighter and larger than it would be otherwise.

Microlensing events are rare, but they can be very valuable to astronomers. By observing microlensing events, astronomers can learn about the mass and distribution of dark matter in the universe, detect exoplanets, and constrain the population of binary stars, neutron stars, brown dwarfs, and red dwarfs in our galaxy.

The team of researchers who predicted the 4,500 new microlensing events also conducted mass estimates to determine the size of the lensing event and where and when the proper alignments would happen between now and 2070. They also employed a cone search method, where the search range expands for each potential lens star, to reduce the possibility of missing future events.

The stars and microlensing events identified by the team could be the subject of follow-up observations by Hubble, the James Webb Space Telescope (JWST), and the proposed Chinese Space Station Telescope (CSST), also known as Xuntian, which China plans to launch sometime next year.

Journal Information: Jie Su et al, Predicting astrometric microlensing events from Gaia Data Release 3, Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad3022. On arXiv: DOI: 10.48550/arxiv.2310.20176