Nature reports:

Stellar detectives have identified seven stars that recently dined on a rocky planet. The study doubles the number of binary stars known to have consumed a planet, and questions the perception that mature solar systems harbouring Earth-like planets are usually stable.

The findings, published in Nature on 20 March, show “strong evidence of planet ingestion”, says Jianrong Shi, an astronomer at the National Astronomical Observatories in Beijing. The planets seem to have been eaten during their stars’ relatively stable main-sequence period, adds study co-author Fan Liu, an astronomer at Monash University in Melbourne, Australia.

If this is true, it means these systems have continued to be chaotic long after their formation, with planets disintegrating or falling into their star, says Johanna Teske, an astronomer at the Carnegie Institution for Science in Washington DC. “It’s an inference at this point. We need to look at these systems in more detail,” she says. [Continue reading…]