A star’s mass decides almost everything about its life, from how bright it shines to how it eventually dies.
But for young stars hidden deep inside clouds of dust, measuring that mass has always been very difficult.
Now, astronomers are finding a new way to solve this problem by watching stars “dance” together in space.
In a new study published in Astronomy & Astrophysics, scientists used the powerful Very Long Baseline Array (VLBA) to measure the masses of young stars in the Orion star-forming region with remarkable precision.
The research was led by Sergio Abraham Dzib Quijano and co-led by Jazmin Ordonez-Toro.
Many stars are not alone. Instead, they exist in pairs called binary systems, where two stars orbit around a shared center of gravity.
Astronomers can use these orbital motions—like two dancers spinning around each other—to calculate how much each star weighs. The faster and tighter the orbit, the stronger the gravity, and the more massive the stars must be.
The Orion region is one of the closest places where new stars are being born, but it is also filled with thick clouds of gas and dust that block visible light. This makes it hard for ordinary telescopes to see what is happening inside. The VLBA solves this problem by observing radio waves, which can pass through dust. This allows astronomers to see stars that would otherwise be hidden.
The VLBA is not just one telescope but a network of radio antennas spread across the United States, from Hawaii to the Virgin Islands. By combining signals from all these locations, it works like a single giant telescope. This gives it extremely high resolution, allowing scientists to detect incredibly small movements in the sky—tiny shifts that would be impossible to see with other instruments.
Over months and years, the researchers tracked the positions of young stars and watched how they moved. These small changes revealed the orbital paths of binary stars. From these motions, the team could directly calculate the stars’ masses without relying on theoretical models.
This is important because existing models of how young stars grow and evolve are not always accurate. In some cases, the new measurements matched predictions well. In others, there were clear differences, suggesting that scientists still need to improve their understanding of early star development.
The observations also revealed new details about these young systems. Some stars had previously hidden companions, and others showed strong magnetic activity, even when they were more massive than expected.
These findings matter because young stars like those in Orion are the starting point for planetary systems. By understanding their masses more accurately, scientists can better predict how stars and planets form and evolve.
With these precise measurements, Orion is becoming a kind of natural laboratory for studying star formation.
By watching the graceful orbital dances of young stars, astronomers are uncovering the fundamental properties that shape the universe—and ultimately, the conditions that make planets and life possible.
