Astronomers Discover Red Dwarf Stars With Impossibly Close Orbits
We may not know everything about the universe, but we have made a lot of observations and drawn some pretty good conclusions from them. One such conclusion was that binary stars could not have orbits under five hours, lest they fuse into one body. However, a new study focusing on dim red dwarf stars has shattered this notion, and may very well challenge our whole notion of how binary stars form.
Binary stars are, simply put, two stars that orbit one another. Previous observations had turned up no pair of stars that managed to accomplish this complicated gravitational ballet in less than five hours per orbit. The thinking was that anything smaller, and faster, would just be impossible. In their study, the Leiden Observatory’s Bas Nefs and his team looked to the dim, low-mass red dwarf stars for an exception.
Though red dwarfs make up the bulk of the stars in our galaxy, they are often overlooked because of their low light output. Using the enormous UKIRT infrared telescope on Hawaii’s Mauna Kea, the team observed 10,000 some red dwarfs. Of these, they found 25 binary systems and, startlingly, four of them with orbits under five hours.
But the really surprising facet of these systems is that our understanding of binary star systems hold that the constituent stars form as pairs. What’s more confusing is that these stars are assumed to have shrunk as they aged, but somehow managed to keep from spinning out of control or merging despite their orbits inching closer and closer together.
The going theory as to how these stars have managed to survive is that the close nature of the orbit itself is making the stars more active. The two stars may be stimulating each other’s magnetic fields as they orbit, causing them to slow as they get closer.
In their report, Universe Today quotes Nefs as saying:
“To our complete surprise, we found several red dwarf binaries with orbital periods significantly shorter than the 5 hour cut-off found for Sun-like stars, something previously thought to be impossible, […] It means that we have to rethink how these close-in binaries form and evolve.”
In short, these stars just blew our minds. Still no word if their close proximity lead to any space-based hijinks ala that other Red Dwarf.