Using Gravitational Microlensing, Astronomers Find Binary Star Composed of Two Brown Dwarfs

Astronomers have found a binary star, which was composed of two brown dwarfs located almost 15,000 light-years away from the Earth. The astronomers used the gravitational microlensing method to detect the star.

A team of astronomers from Chungbuk National University in Cheongju, South Korea has reported detecting this brown-dwarf star was detected using the gravitational microlensing. The astronomers were led by Cheongho Han and the two brown dwarf stars were detected during the microlensing event OGLE-2016-BLG-1469. They have submitted the finding in the Arxiv scientific repository on May 16.

OGLE-2016-BLG-1469 is the gravitational microlensing event which was observed by many ground observatory and also NASA's Spitzer Space Telescope. OGLE stands for Optical Gravitational Lensing Experiment, the astronomical project that searches for the dark matter using gravitational microlensing, and first initiated in 1992 by Polish astronomer Andrzej Udalski. This year, the project will celebrate the 25 years of gravitational microlensing project at the University of Warsaw.

The discovery of the two binary dwarf stars is a collaborative effort from a team of more than 50 astronomers to observe the dark matter with the gravitational microlensing. The astronomers were divided into three research groups, they are the Korea Microlensing Telescope Network (KMTNet), the Optical Gravitational Lensing Experiment (OGLE) and the Microlensing Observations in Astrophysics (MOA).

For their collaborative work, KMTNet used three identical 1.6m telescopes simultaneously at the Cerro Tololo Inter-American Observatory, South African Astronomical Observatory and Siding Spring Observatory, in Chile, South Africa, and Australia respectively. While OGLE utilized the 1.3m telescope at the Las Campanas Observatory in Chile. Lastly, the MOA deployed the 1.8m telescope at the Mt. John University Observatory in New Zealand.

Since its first initiation, using the astronomical phenomenon of gravitational microlensing has helped astronomers to discover many space object that emits a very little light. Watch the explanation from the European Space Agency regarding the gravitational microlensing below: