Dance of the Invisible Giants: Gaia Finds a 'Desert' of Brown Dwarfs ⚡ экспресс
Using Bayesian inference based on astrometric data from Gaia DR3 for nearby (within 200 pc) sun-like stars and assuming single companions, the authors identified 2,673 systems (2.41% of the sample) with signs of companions of brown dwarf mass and orbital period less than 5 years. After accounting for observational biases, the true fraction of such stars is estimated at 10.4 (+0.8 / –0.6)%, significantly higher than previously reported values (<1%). Acknowledging the limitations of DR3 and the lack of epoch measurements, the researchers modeled scenarios with multiple systems and showed that some signals could be explained by several low-mass brown dwarfs and massive planets (>10 MJ), while high-mass brown dwarfs (>50 MJ) on short periods are rare. These results allow predicting the number of similar companions in the future DR4 release.
Sun-like stars rarely spin alone. Many of them dance with invisible partners — brown dwarfs: objects bigger than planets but too lightweight for steady stellar burning. In their cores, hydrogen fusion flickers, only to fade fast, never matching the stability of the Sun.
Yet on orbits shorter than five years, such couples were deemed nearly impossible. Astronomers labeled this gap the 'brown dwarf desert.'
Everything shifted with the Gaia telescope. It is so precise it can catch a star's faint wobble, as delicate as a hair's breadth from thousands of kilometers away. Surveying 110,000 suns, Gaia detected signs of brown dwarfs around one in ten — tenfold more than before. Most turned up right in the 'desert' once branded barren. The 'desert' was a mirage, and brown dwarfs were simply hiding at the edge of our sight. Bulky brown dwarfs (heftier than 50 Jupiters) remain scarce, but the lighter ones have flooded this zone. The full story awaits the upcoming Gaia DR4 catalog, which will unveil just how lively this former desert really is.
🎯 Those 'failed stars,' brown dwarfs, brew clouds of scorching sand and downpours of liquid iron — sounding more like overachieving giant planets.