Gemini South Telescope — International Gemini Observatory/NOIRLab/NSF/AURA/T. Slovinský

Astronomers Just Found a "Mystery Object" Surrounded By a Metallic Wind Cloud

A recent article from The Independent has highlighted a dramatic astronomical finding by a team led by a current IAS scholar: a “mystery object” several times the mass of Jupiter or larger, orbited by a giant metallic wind cloud.

The team of researchers, headed by Nadia Zakamska, Member in the School of Natural Sciences, and which includes James Owen, NASA Hubble Fellow (2014–17) in the School, was clued in to the cloud’s existence because of an anomalous “dimming event.” In September 2024, the All-Sky Automated Survey for Supernovae (ASAS-SN) identified a star that suddenly became 40 times dimmer. “Stars like the sun don’t just stop shining for no reason,” Zakamska said. “So dramatic dimming events like this are very rare,” she explained.

Zakamska NOIRLab — International Gemini Observatory/NOIRLab/NSF/AURA/P. Marenfeld & M. Zamani

Artist’s illustration showing a large disk of planetary debris, surrounded by a thick cloud of dust and gas, passing in front of a star.

The astrophysicists hypothesized that the star was occulted by a passing cloud and set out to study it during the 9-month event. Using a telescope located in Chile—named Gemini South—the team discovered that the occulting cloud is producing gaseous emission of metals, including iron and calcium. “When I started observing the occultation with spectroscopy, I was hoping to unveil something about the chemical composition of the cloud, as no such measurements had been done before. But the result exceeded all my expectations,” said Zakamska.

The cloud “is bound by gravity to a second object that orbits the star.” In a press release issued by NOIRLab, the scholars suggested that the object could be a brown dwarf or low-mass star.