Key Points
- Astronomers used NASA’s Chandra X-ray Observatory to study a mysterious supergiant star called Wd1-9.
- The star was hidden inside a “dusty cocoon,” but X-rays allowed scientists to see through it.
- The observations revealed that Wd1-9 is not a single star, but a binary system of two stars orbiting each other.
- The key evidence was a regular 14-day cycle in the star’s X-ray light, believed to be the orbital period.
An international team of astronomers has solved a long-standing mystery about a rare and massive star, revealing that it’s not one star, but two. The star, known as Wd1-9, is a type of “supergiant” that has puzzled scientists for years because it’s shrouded in a thick, dusty cocoon, making it impossible to see clearly with normal telescopes.
To solve the puzzle, the team used NASA’s powerful Chandra X-ray Observatory. Unlike visible light, X-rays can pierce through the dust cloud, giving astronomers a clear view of what’s happening at the star’s core.
Published on the arXiv preprint server, the new observations provided the smoking gun. The astronomers discovered that Wd1-9’s X-ray emissions varied on a regular 14-day cycle. They concluded that this is the orbital period—the time it takes for two stars to circle each other. They also detected strong signals from certain elements that are a clear signature of a binary system.
Before this discovery, scientists had several theories about Wd1-9, which is located about 13,800 light-years away. But the new X-ray data provides the most detailed look at the star to date and strongly suggests it is a binary system. This helps scientists better understand the lives and evolution of these rare and massive stars.
