Brown dwarfs get a bad rap in the stellar world, often labeled as "failed stars" for their inability to sustain nuclear fusion at their cores. The mass of these objects falls between planets and stars, ranging from 13 to 80 times the mass of Jupiter. Because they aren't massive enough to sustain fusion, they are far fainter and cooler than their stellar comrades.
Now, a new finding led by researchers at Caltech shows how these dim bulbs can join together to shine brightly. Searching through archival observations captured by the Zwicky Transient Facility (ZTF) at Caltech's Palomar Observatory, researchers have identified a very tight-knit pair of brown dwarfs in which one is actively siphoning material from the other.
Ultimately, the brown dwarfs are expected to merge to form a new star; alternatively, the brown dwarf gaining the extra mass will ignite to become a star. Either way, a pair of failed stars will have created a brilliant new star.
"The failed stars get a second chance," says Samuel Whitebook, a Caltech graduate student and lead author of a new report on the findings appearing in The Astrophysical Journal Letters. "Brown dwarfs don't have internal engines like stars do, but this result shows they can exhibit very interesting dynamic physics."
Whitebook works with two advisors at Caltech, Tom Prince, the Ira S. Bowen Professor of Physics, Emeritus, and Dimitri Mawet, the David Morrisroe Professor of Astronomy and a senior research scientist at NASA's Jet Propulsion Laboratory, which is managed by Caltech. Both Prince and Mawet are co-authors on the study.
The finding is a first of its kind: Until now, this type of mass transfer between binary objects had only been seen in much heavier objects, such as white dwarfs, which are the dead corpses of stars like our Sun.
