W.M. Keck Observatory | University of California, San Diego | 2020 Mar 09
Astronomers working on “first light” data from a newly commissioned telescope in Chile made a chance discovery that led to the identification of a rare eclipse of two brown dwarfs. ...
Sometimes called “failed stars,” brown dwarfs occupy a grey zone between stars and giant planets. They are unable to sustain the fusion of hydrogen into helium, a process that powers the light from normal stars like the sun; yet they appear to form like stars, only with less mass. They provide a critical link in scientists’ understanding of star and planet formation.
The chance discovery was led by an international team of researchers ... working on a project called SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars), which aims to find planets orbiting the smallest stars, including brown dwarfs. SPECULOOS finds planets by detecting periodic dips in a star’s brightness as a planet passes in front of it, an event called a planetary transit. Astronomers predict that the smallest stars and brown dwarfs could host large populations of close-in, potentially habitable rocky planets, like the famous seven-planet system TRAPPIST-1 that was discovered in 2017 by members of the same team. ...
Soon after the construction of the first SPECULOOS telescopes in Chile, and during early testing observations, the team targeted the brown dwarf 2MASSW J1510478-281817, also known as 2M1510, in the constellation Libra. In this case, the SPECULOOS observations picked up a distinct signal that led the researchers to speculate that 2M1510 might be two brown dwarfs instead of one, in orbit around each other. ...
The detection of an eclipsing brown dwarf binary is extremely rare because the system needs to be precisely aligned with the line-of-sight to move in front of each other. Only one other such system has been identified to date. These systems allow astronomers to measure both the radii and masses of the brown dwarfs directly. 2M1510 is also unique in that it is among the few brown dwarfs that have a known age, due to its membership in a nearby cluster of young stars called the Argus moving group. The eclipsing binary is also part of a brown dwarf triple system—another rarity—with a third component orbiting at a much wider separation. ...
An Eclipsing Substellar Binary in a Young Triple System Discovered by SPECULOOS ~ Amaury H.M.J. Triaud et al
- Nature Astronomy (online 09 Mar 2020) DOI: 10.1038/s41550-020-1018-2
- arXiv.org > astro-ph > arXiv:2001.07175 > 20 Jan 2020 (v1), 23 Jan 2020 (v2)