Imagine a giant pot of boiling soup, but instead of water, it’s scorching hot plasma, and the pot is a star 300 times larger than our sun! That’s the scene astronomers have captured for the first time, revealing turbulent activity on a star other than our own. Using the powerful Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, scientists have obtained detailed images of R Doradus, a red giant star located about 180 light-years away in the constellation Dorado.
These images showcase enormous gas bubbles, driven by heat rising from the star’s core, erupting on the surface of R Doradus. These bubbles, which can swell to an astonishing 75 times the size of our sun, appear to slightly deform the star as they crash violently on its surface. “It is spectacular that we can now directly image the details on the surface of stars so far away,” said Behzad Bojnodi Arbab, a doctoral student at Chalmers University of Technology in Sweden and a co-author of the study published in the journal Nature. “Thanks to the latest images, astronomers can now “observe physics that until now was mostly only observable in our sun.”
The images reveal that the plasma bubbles rise and fall on a one-month cycle, which is faster than the timeline followed by similar convective cells on our sun’s surface. This faster cycle suggests that convection, the process of heat transfer, changes as a star ages. “We don’t yet know what is the reason for the difference,” said Wouter Vlemmings, a professor at Chalmers University of Technology and lead author of the study.
These observations offer a glimpse into the future of our own sun, which is expected to enter its red giant phase in about five billion years. As our sun ages, it will expand to swallow Mercury and Venus, and its surface will become more turbulent. R Doradus, despite its enormous size, has a mass similar to our sun, providing valuable insights into how our sun will evolve.
The high-quality images from ALMA not only provide a captivating visual spectacle but also contribute to our understanding of stellar evolution and the dynamic processes occurring on the surfaces of stars. The observations of R Doradus demonstrate the remarkable capabilities of ALMA in unveiling the hidden details of celestial objects, further expanding our knowledge of the cosmos.
