Giant ‘metal cloud’ spotted in nearby star system could be hiding a second alien sun
A giant cloud of vaporized metal could hide a secret planet or second alien sun in a nearby star system, a new study reveals.
The mysterious cloud is up to 15,000 times larger than our planet and caused its home star to almost completely disappear from telescope observations for nearly nine months as the ghostly object oozed between its host star and Earth.
The astronomers were first alerted to the presence of the mysterious cloud in September 2024, when they detected a surprise dimming event surrounding the star J0705+0612 (sometimes called ASASSN-24fw) – a Sun-like main sequence star located about 3,000 light-years from Earth. The star’s brightness was suddenly reduced by a factor of 40, to about 3% of its original brightness, and remained that way for just over eight and a half months before returning to full brightness in May 2025.
In the study, published January 21 in The astronomical journalZakamska and her team analyzed this strange event using data captured by the Gemini South telescope and the Magellan telescopes in Chile, and discovered that a massive object had passed in front of or obscured J0705+0612. After ruling out features such as giant planets and asteroid belts, which were too small or too diffuse to block so much light for so long, the researchers concluded that the obscuring object was a thick cloud of molecular gas.
The unnamed cloud measures about 125 million miles (200 million kilometers) in diameter and is positioned about 13.3 astronomical units (or about 13.3 Earth-Sun distances) from J0705+0612. For context, this would place it halfway between Saturn And Uranus if it were located in our solar system. At this distance, it takes about 44 years for the cloud to completely orbit its home star.
Gemini South newly operational Gemini high resolution optical spectrograph (GHOST), which captures specific wavelengths of light emitted by different molecules, played a key role in the study. It probed deeper into the cloud than other telescopes can, allowing researchers to probe exactly what the cloud was made of.
The results “exceeded all expectations,” revealing an abundance of metals, such as iron and calcium, Zakamska said. The GHOST data also allowed the team to track subtle movements in the cloud, which is “something we’ve never been able to do before in a system like this,” she added.
After examining the cloud’s movements, it quickly became clear that the metallic mass was held together by a heavy object at its center. Depending on the size of the cloud, it could be a gas giant several times larger than Jupitera low-mass star in a binary pair with J0705+0612, or a brown dwarf — a a sort of planet-star hybrid it’s more massive than Jupiter but not massive enough to support nuclear fusion at its core.
If the cloud surrounds a star, then it would be classified as a circumsecondary disk because its host star is the secondary, or smaller, star of its binary pair. But if it is held together by a planet, then it would be dubbed a circumplanetary disk. The researchers suggest that the cloud is more likely held together by a star, due to the high levels of infrared radiation emitted by the cloud. However, it is too early to be sure.
The next mystery is how the cloud formed. The researchers predict the cloud is about 2 billion years old, suggesting it is younger than J0705+0612, which is likely closer in age to J0705+0612. the sun (about 4.6 billion years). This would mean that it is not a legacy of the creation of the star system, like most other similar disks.
Instead, researchers predict that it was born from a planetary collision, similar to that of the one who gave birth to the moon. This would explain not only the age of the cloud, but also its surprisingly high metal content, the researchers say.
“This event shows us that even in mature planetary systems, dramatic large-scale collisions can still occur,” Zakamska said. “It is a striking reminder that the universe is far from static: it is an ongoing story of creation, destruction and transformation.”
Researchers will likely learn more about this mysterious cloud in 2068, during its next passage between J0705+0612 and Earth.
