A Stunning Stellar Outcome: ALMA Sees the Aftermath of a Fight to the Death Between Binary Stars
According to an official release from the European Southern Observatory (ESO), astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope have captured the results of an explosive fight to the death between binary stars.
Binary star system HD101584 is comprised of one larger star similar to the Sun paired with a small low-mass companion star. When the larger star (and, eventually our Sun) reach the end of their life-cycle, they burn off the last of their hydrogen and rapidly expand into a red giant. This is exactly what happened – but then it started to swallow the smaller star.
"The star system HD101584 is special in the sense that this 'death process' was terminated prematurely and dramatically as a nearby low-mass companion star was engulfed by the giant," explained Hans Olofsson, a professor of radio astronomy at Chalmers University of Technology in Sweden, who led the study.
When the red giant began to devour its companion star, the smaller star swerved inward and narrowly missed colliding with the giant's fiery core. This "triggered" the gas giant to shed its outer layers – essentially turning the pair into a beautiful miniature nebula.
Researchers say getting to watch this sped-up process play out was a one-in-a-lifetime opportunity to learn about how stars like the Sun die by observing it directly. According to one of the study's co-authors, Sofia Ramstedt from Uppsala University in Sweden, "Currently, we can describe the death processes common to many Sun-like stars, but we cannot explain why or exactly how they happen. HD101584 gives us important clues to solve this puzzle since it is currently in a short transitional phase between better studied evolutionary stages. With detailed images of the environment of HD101584 we can make the connection between the giant star it was before, and the stellar remnant it will soon become."
ALMA is actually a fleet of 66 massive telescopes spread out across the Atacama Desert in northern Chile near Bolivia. ALMA observes the electromagnetic spectrum via radio waves, and the high altitude combined with low humidity makes for the clearest "vision." Elizabeth Humphreys – a co-author from the ESO in Chile – noted, "This stunning image of the circumstellar environment of HD101584 would not have been possible without the exquisite sensitivity and angular resolution provided by ALMA."
The study has been published in the industry journal Astronomy and Astrophysics.
Cover Image Credit: ALMA (ESO/NAOJ/NRAO), Olofsson et al. Acknowledgement: Robert Cumming – CC BY 4.0