Habits of planet-eating twin stars

The researchers studied twin stars that should have the same composition. However, to the astronomers' surprise, they disagreed in about eight percent of these cases.

The research group, whose member Meredith Joyce, winner of the Marie Curie Extension Grant at the Konkoly Thege Miklos Institute for Astronomy at HUN-REN CSFK Konkoly Thege (HUN-REN CSFK KTM CSI), came to the conclusion that the difference is caused by whether One of the stars has planets or engulfed planetary debris – read the HUN-REN Astronomy and Earth Sciences Research Center's announcement on Thursday.

According to the report, the results required the use of the largest telescopes: the researchers used the 6.5-meter Magellan telescope in Chile and the 8-meter VLT telescopes of the European Southern Observatory, and they also relied on data from the 10-meter Keck telescope in Hawaii. .

“We looked at two twin stars moving together. They were born from the same molecular cloud, so they must be identical,” Fan Leeuw, a researcher at Monash University in Melbourne and lead author of the technical article, was quoted as saying. Advertising. He explained: “Thanks to a high-resolution analysis, we found chemical differences between the twins. This is very strong evidence that one of the stars absorbed planets or planetary materials and changed their composition.”

This phenomenon occurred in at least seven of the 91 twin star pairs examined, in about eight percent of the sample. What makes the result special is that these stars, like the Sun, are in the prime of their lives – so-called main sequence stars, not red giants in the final stages of their lives. “This is different from previous studies, where late-stage red giant stars can engulf nearby planets,” Fan Liu added.

According to the statement, there is some doubt about whether stars are swallowing planets whole, or whether debris remaining from planetary formation is flowing onto them. The authors believe that both are possible. Whatever is true, it would be difficult to explain the chemical differences between pairs of stars in any other way, such as internal processes in stars.

Meredith Joyce specializes in the interior physics and evolution of stars. For two years, the American researcher joined the Miklós Konkoli-Thej Institute of Astronomy, internationally recognized in the field of stellar physics, to model the processes occurring in stars. According to him, observing star pairs was absolutely necessary to identify planet-destroying stars.

According to the statement, the findings could have far-reaching consequences for the study of the long-term evolution of planetary systems. They also shed new light on the stability of planetary systems orbiting binary star systems. In the future, researchers want to expand the sample of stars examined. Understanding when and how often stars engulf their planets could have a fundamental impact on the spread of life or intelligence around other stars in the Milky Way.

This study is part of a larger collaboration, the Complete Census of Together-Moving Object Pair (C3PO) initiative, which aims to observe all the bright, together-moving stars identified by the Gaia space astronomical telescope. Researchers from Swinburne University of Technology in Australia, University College Cork in Ireland, Carnegie Observatories, Ohio State University, and Dartmouth College in the United States, HUN-REN CSFK in Hungary, and the Max Planck Institute for Astrophysics in Germany participated in the research. .

-MTI-