Astronomers have discovered a vast cloud filled with vaporized metals and powerful winds orbiting a mysterious object far from its host star.
The finding offers a rare look at dramatic events that can still reshape planetary systems billions of years after they first form.
The discovery began in September 2024, when a star known as J0705+0612, located about 3,000 light-years from Earth, suddenly faded to just one-fortieth of its normal brightness.
The dimming lasted for nearly nine months, until May 2025. Because the star is similar to our Sun, this extreme and prolonged drop in light immediately caught scientists’ attention.
“Stars like the Sun don’t simply fade without a reason,” said Nadia Zakamska, an astrophysicist at Johns Hopkins University who led the study.
Events like this are exceptionally rare, making it a unique opportunity to investigate what was happening around the star.
Zakamska and her team quickly launched observations using several major telescopes, including the Gemini South telescope in Chile.
Their results, published in The Astronomical Journal, show that the star was temporarily blocked by a huge cloud of gas and dust slowly passing in front of it.
This cloud is enormous. It is roughly 200 million kilometers across and sits about two billion kilometers away from the star. The researchers found that it is not floating freely in space. Instead, it is held together by the gravity of a second object orbiting the star far from the center of the system.
The nature of this object remains unclear. It must be at least a few times more massive than Jupiter, but it could be a large planet, a brown dwarf, or even a very small star. If it is a star, the cloud would be a disk of material orbiting the smaller member of a binary star system. If it is a planet, the cloud would be a rare example of a disk surrounding a planet. In either case, seeing such a disk pass directly in front of a star is extremely unusual.
To learn what the cloud is made of, the team used a powerful instrument called GHOST on the Gemini South telescope. This device splits starlight into its component colors, revealing chemical fingerprints. The data showed that the cloud contains several metals, including iron and calcium.
Even more striking, the observations allowed astronomers to measure how the gas inside the cloud is moving. They detected fast winds of metallic gas swirling through the disk, marking the first time scientists have directly measured internal gas motions in a disk orbiting a planet or low-mass companion.
The star itself is more than two billion years old, so the disk cannot be leftover material from the system’s birth. Instead, the researchers suggest it may have formed after a violent collision between two large planets, which would have produced huge amounts of dust and gas.
The discovery shows that planetary systems can remain active and chaotic long after they mature. With new instruments like GHOST, astronomers are now uncovering hidden events that reveal just how dynamic the universe still is.
Source: KSR.
