Science matters. Wonder matters. You matter. Join our 2025 Donation Campaign today.<\/strong><\/p>\n ESA published this original story on April 29, 2025. Edits by EarthSky.<\/p>\n Stars in the Milky Way tend to form in families, with similar stars springing to life in roughly the same place at roughly the same time. These stars later head out into the wider galaxy when they\u2019re ready to fly the nest. While smaller groups can completely dissipate, siblings from sizeable families usually move similarly and largely travel together.<\/p>\n We have seen many star families with Gaia. We\u2019ve spotted strings of stars stretching out across the Milky Way and remaining intact for billions of years. We\u2019ve mapped the ancient star streams that wound together to form the earliest structure of our galaxy. And we\u2019ve put together a stellar family portrait of our cosmic home. By studying star families we can piece together not only the characteristics and behavior of the stars themselves but also learn about how our galaxy is evolving as a whole.<\/p>\n Using Gaia data, scientists have now spotted a star family unlike any other. It\u2019s a massive family of more than 1,000 young stars behaving oddly. Despite its size, the family \u2013 dubbed Ophion \u2013 will soon have completely dispersed in record time, leaving just an empty nest behind.<\/p>\n Dylan Huson of Western Washington University is the lead author of the new peer-reviewed paper. The Astrophysical Journal<\/em> published the study on April 25, 2025. Huson said: <\/p>\n Ophion is filled with stars that are set to rush out across the galaxy in a totally haphazard, uncoordinated way, which is far from what we\u2019d expect for a family so big. What\u2019s more, this will happen in a fraction of the time it\u2019d usually take for such a large family to scatter. It\u2019s like no other star family we\u2019ve seen before.<\/p>\n<\/blockquote>\n To find Ophion, Huson and colleagues developed a new model. It explores Gaia\u2019s vast, unrivalled trove of spectroscopic data to learn more about young, low-mass stars lying reasonably near to the sun. They applied this model, named Gaia Net, to the hundreds of millions of stellar spectra released as part of Gaia\u2019s data release 3. Then they narrowed their search to \u201cyoung\u201d stars of under 20 million years in age \u2026 and out jumped Ophion.<\/p>\n ESA Gaia project scientist Johannes Sahlmann said: <\/p>\n This is the first time that it\u2019s been possible to use a model like this for young stars, due to the immense volume and high quality of spectroscopic observations needed to make it work. It\u2019s still pretty new to be able to reliably measure the parameters of lots of young stars at once. This kind of bulk observing is one of Gaia\u2019s truly unprecedented achievements.<\/p>\n Another is how the Gaia mission is creating opportunities for new collaborative and interdisciplinary science through its open data policy. Several members of the Ophion discovery team are undergraduate and postgraduate students in computer science, who used Gaia data to innovate and develop new methods that are now offering new insights into the stars of the Milky Way.<\/p>\n<\/blockquote>\n The question remains: Why is Ophion behaving so unusually?<\/p>\n The scientists discuss several options. The star family resides around 650 light-years away. It\u2019s near some other massive gatherings of young stars. Energetic events within and interactions between these colossal neighbors may have influenced Ophion through the years.<\/p>\n There are also signs that stars have exploded here in the past. These supernova bursts could have swept material away from Ophion and caused its stars to move far more rapidly and erratically than before. Co-author Marina Kounkel of the University of North Florida said:<\/p>\n We don\u2019t know exactly what happened to this star family to make it behave this way, as we haven\u2019t found anything quite like it before. It\u2019s a mystery.<\/p>\n Excitingly, it changes how we think about star groups, and how to find them. Previous methods identified families by clustering similarly moving stars together, but Ophion would have slipped through this net. Without the huge, high-quality datasets from Gaia, and the new models we can now use to dig into these, we may have been missing a big piece of the stellar puzzle.<\/p>\n<\/blockquote>\n After more than a decade spent mapping our skies, Gaia stopped observing in March. This marks the end of the spacecraft\u2019s operations. But it\u2019s just the beginning of the science. Many more discoveries are anticipated in the coming years, along with Gaia\u2019s biggest data releases yet. (Data Release 4 is planned toward the end of 2026, and the Gaia legacy data release is planned for publication not before the end of 2030).<\/p>\n Read more about saying farewell to Gaia.<\/p>\n Bottom line: The Gaia mission has spotted a family of stars that is getting to ready to leave home in record time and zip in all directions across the galaxy.<\/p>\n Source: Gaia Net: Toward Robust Spectroscopic Parameters of Stars of all Evolutionary Stages<\/p>\n Via ESA<\/p>\n <\/div>\n\n
Odd family of stars desperate to leave home<\/h3>\n
A family like no other<\/h3>\n
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![\"Family](\"https:\/\/earthsky.org\/upl\/2025\/04\/Gaia_spots_odd_star_family-ESA-Gaia-DPAC.jpg\")
A new model found the family of stars<\/h3>\n
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Solving the mystery<\/h3>\n
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Gaia is done but its data lives on<\/h3>\n