Dartmouth Study Reveals New Details About Cataclysmic Binary Stars
A team of astronomers led by Dartmouth College professor John Thorstensen has published new details about the life cycle of cataclysmic binary stars, a class of stars that are made up of a dead star called a white dwarf and a star like our sun.
The study, which was published in the journal The Astronomical Journal, used data from the South African Astronomical Observatory to track the orbital periods of seven cataclysmic binaries. The researchers found that all seven stars were typical, circling each other in periods of a few hours.
"These systems share similar physics, but depending on what type of secondary star you have, they can appear very different," said Abigail Burrows, a co-author of the study and an astronomy major at Dartmouth.
The researchers also found that four of the stars they studied were persistently bright, in a class known as nova-like variables, while the others were dwarf novae with small outbursts.
"This is the first time that we've been able to study a large sample of cataclysmic binaries in this way," said Thorstensen. "The data is helping us to better understand how these stars evolve and how they interact with each other."
The study also provides new insights into the life cycle of white dwarfs. Before, astronomers thought that white dwarfs were simply the dense cores of dead stars that had run out of fuel. However, the new data suggests that white dwarfs can actually be revived by siphoning off gas from their neighbors.
"It's so interesting to think of the process as a rebirth," said Chase Alvarado-Anderson, another co-author of the study and an astronomy major at Dartmouth.
The research team is continuing to study cataclysmic binary stars, and they hope to learn more about how these stars evolve and how they interact with each other. The findings could help astronomers to better understand the life cycle of stars and the evolution of galaxies.
In addition to Thorstensen, Burrows, and Alvarado-Anderson, the research team also included astronomers from the University of Cape Town and the South African Astronomical Observatory. The study was funded by the National Science Foundation.
Journal Information: John R. Thorstensen et al, Optical Studies of Seven Bright Southern Cataclysmic Variable Stars, The Astronomical Journal (2023). DOI: 10.3847/1538-3881/ace7bf