When A Black Hole Shreds A Star, A Bright Flare Tells The Story
Enrico Ramirez-Ruiz uses computer simulations to explore the universe’s most violent events, so when the first detailed observations of a star being ripped apart by a black hole were reported in 2012 (Gezari et al., Nature), he was eager to compare the data with his simulations. He was also highly skeptical of one of the published conclusions: that the disrupted star was a rare helium star.
“I was sure it was a normal hydrogen star and we were just not understanding what’s going on,” said Ramirez-Ruiz, a professor of astronomy and astrophysics at the University of California, Santa Cruz.
In a paper accepted for publication in the Astrophysical Journal and available online at arXiv.org, Ramirez-Ruiz and his students explain what happens during the disruption of a normal sun-like star by a supermassive black hole, and they show why observers might fail to see evidence of the hydrogen in the star. First author and UCSC graduate student James Guillochon (now an Einstein Fellow at Harvard University) and undergraduate Haik Manukian worked with Ramirez-Ruiz to run a series of detailed computer simulations of encounters between stars and black holes.