Snatching matter helps blue stragglers stay hot and look young
K. Garmany, F. Haase NOAO/AURA
Stealing keeps some stars looking young. The thieves, called blue stragglers, swipe material from a neighbor, leaving behind a dead stellar companion as a calling card, data from the Hubble Space Telescope show.
Natalie Gosnell, an astronomer at the University of Wisconsin–Madison, and her colleagues discovered three blue stragglers that share orbits with white dwarfs, the remnants of dead stars. The findings, posted January 29 on arXiv.org, match astronomers’ ideas about what would be left if a blue straggler took gas from a now-defunct companion star. The stolen goods allow the blue stragglers to burn hotter and look bluer, as a much younger star would.
“These blue stragglers absolutely did form from taking matter from another star. It is the first time we have been able to say that for a specific population of blue stragglers,” Gosnell says.