The Pleiades, also known as the “Seven Sisters,” is one of the most recognizable sights in the night sky.
For centuries, people around the world have admired this glittering cluster of stars.
But new research reveals that what we see with the naked eye is only a small part of a much larger cosmic family.
Astronomers from the University of North Carolina at Chapel Hill have discovered that the Pleiades star cluster is surrounded by thousands of related stars spread across a vast region of space.
This huge structure, which they’ve named the Greater Pleiades Complex, is about 20 times larger than previously thought.
Their findings, published in The Astrophysical Journal, completely change how scientists understand this famous group of stars.
The team made the discovery by combining data from NASA’s Transiting Exoplanet Survey Satellite (TESS) and the European Space Agency’s Gaia telescope.
These powerful observatories allowed researchers to measure how fast stars spin and how they move through space. Young stars rotate quickly, while older stars spin more slowly, so rotation acts like a “cosmic clock” that helps determine a star’s age.
By comparing spin rates and motions, the researchers were able to identify thousands of stars that share the same characteristics as the Pleiades. Many of these stars are now scattered across the sky, but their shared origins reveal that they were all born from the same giant cloud of gas and dust millions of years ago.
“This study changes how we see the Pleiades,” said lead author Andrew Boyle, a graduate student at UNC-Chapel Hill. “They’re not just seven bright stars but part of a massive stellar family stretching across the sky.”
The discovery has major implications for how astronomers map and understand our galaxy. According to co-author Professor Andrew Mann, the finding suggests that many nearby stars once belonged to larger groups that have gradually drifted apart. “Our work provides a new way to uncover these hidden relationships,” he said.
The Pleiades holds a special place not only in science but also in human culture—from ancient references in the Old Testament and Māori New Year celebrations (Matariki) to the logo of Subaru cars in Japan.
By studying how stars spin and move, scientists hope to uncover more of these vast, extended families—including possibly the one our own sun was born into. As Boyle put it, “We’re opening a new window into the hidden structure of our galaxy.”
Source: University of North Carolina at Chapel Hill.
