Dance of the Invisible Giants: Gaia Finds a 'Desert' of Brown Dwarfs ⚡ экспресс
Brown dwarfs — objects of intermediate mass between planets and stars — are almost never found around sun-like stars with orbital periods less than 5 years: this scarcity is called the 'brown dwarf desert'. Using precise astrometry (measurements of stellar wobbles) from the Gaia DR3 catalog and Bayesian analysis, scientists studied nearby stellar systems and found 2,673 candidates — significantly more than expected. After correcting for observational limitations, it turned out that about 10% of nearby stars could have a brown dwarf mass companion with a period up to 5 years, whereas previously it was thought to be less than 1%. It's as if a census suddenly revealed that every tenth apartment is occupied by invisible tenants.
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.