Three star clusters, one origin story: Are Orion, Pleiades and Hyades connected? Scientists think so

The constellation Orion is shown with the Orion Nebula Cluster marked as the central “star” in Orion’s sword, alongside the Pleiades and Hyades clusters, each outlined with large yellow circles. (Image: Aladin sky atlas/CDS Strasbourg Observatory, France)

When looking at the night sky, it’s easy to imagine stars simply twinkling in place. But new findings suggest some of the sky’s most famous clusters may share a deeper connection. A team of astrophysicists now believes that the Orion Nebula, Pleiades and Hyades are not just neighbours in space—they might be different stages of one stellar family’s life.

One Birth, Three Ages
The Orion Nebula Cluster is just 2.5 million years old. It's full of young stars and gas, actively forming new suns. Pleiades is older, around 100 million years. Hyades, with fewer stars, is roughly 700 million years old. Each cluster is shaped by time and distance, yet researchers say their origins may be the same.

Simulations by scientists from Iran’s IASBS and the University of Bonn support this theory. The team traced the evolution of these clusters across 800 million years. They found that a young cluster like Orion could evolve into Pleiades, then into Hyades. Their computer models also match observed features like star count, shape and distribution.

Star Clusters Age Like People
Professor Pavel Kroupa from the University of Bonn compares them to life stages. “It’s like seeing baby, teen and elder versions of one person,” he said. The study suggests that star clusters may form in a preferred way inside molecular clouds. That could explain the similar paths taken by different groups of stars.

The researchers believe the Orion Nebula started as a tight, massive cluster. Over time, it expanded and lost gas and stars, becoming more like Pleiades. Later, it thinned out further, resembling Hyades. Even after losing many stars, the core remains intact.

More Than Just a Coincidence
All three clusters sit near each other in the sky. This unusual alignment has long intrigued astronomers. The researchers now think it might reflect a shared birthplace in the galaxy’s past. The study also highlights how internal and external forces—like gravity and star interactions—shape these cosmic families.

Dr. Akram Hasani Zonoozi of IASBS, now working in Bonn, says the research shows the fine balance between star dynamics and galactic influence. “It brings us closer to understanding how these beautiful clusters grow old,” she said.

The study not only helps explain the lives of Orion, Pleiades and Hyades. It also gives scientists better tools to study other star groups and their histories, using both simulations and real data from the sky.