Examination of Theia 456 finds its nearly 500 stars were born at same time.

The Milky Way houses 8,292 recently discovered stellar streams — all named Theia.

A stellar stream is a rare linear pattern — rather than a cluster — of stars.

After combining multiple datasets captured by the Gaia space telescope, a team of astrophysicists found that all of Theia 456’s 468 stars were born at the same time and are traveling in the same direction across the sky.

“Most stellar clusters are formed together,” said Jeff Andrews, a Northwestern University astrophysicist and member of the team.

“Theia 456: A New Stellar Association in the Galactic Disk” took place on January 15, 2021, as a part of a session on “The Modern Milky Way.”.

“As we’ve started to become more advanced in our instrumentation, our technology and our ability to mine data, we’ve found that stars exist in more structures than clumps,” Andrews said.

Most stellar streams are found elsewhere in the universe — by telescopes pointed away from the Milky Way.

Andrews and his team found that the 468 stars within Theia 456 had similar iron abundances, which means that — 100 million years ago — the stars likely formed together.

With the help of data from NASA’s Transiting Exoplanet Survey Satellite and from the Zwicky Transient Facility — both of which produced light curves for stars in Theia 456 — Andrews and his colleagues were able to determine that the stars in the stream do share a common age.

The team also found that the stars are moving together in the same direction.

“If you know how the stars are moving, then you can backtrack to find where the stars came from,” Andrews said.

January 17, 2021

January 17, 2021

January 17, 2021

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January 16, 2021

January 16, 2021