HD 81809B Shows Planet-Eating Signs After Swallowing Up to 75 Earth Masses
Updated
Updated · Space.com · Jun 17
HD 81809B Shows Planet-Eating Signs After Swallowing Up to 75 Earth Masses
1 articles · Updated · Space.com · Jun 17
Summary
Astronomers found HD 81809B and its binary companion, 101 light-years away, have sharply different surface chemistry—an unusual mismatch for stars born from the same gas cloud.
High lithium levels in HD 81809B provide the key evidence that it engulfed planetary material, with researchers estimating the star consumed about 50 to 75 Earth masses.
The team says the meal may have happened a few million years ago, possibly after binary-star gravitational interactions destabilized a planet’s orbit and sent it into the star.
Researchers cannot yet tell whether HD 81809B swallowed one large planet or several smaller ones, though a debris disk in the system could eventually reveal more if future instruments can study it.
The pre-peer-reviewed study would mark the first known binary system with this kind of chemical split, offering a rare way to trace past planet engulfment.