Astronomers Witness Extraordinary Phenomenon on Red Giant Star R Doradus
In a groundbreaking discovery, astronomers have captured the first-ever images of boiling gas bubbles on the surface of a distant star. The star, known as R Doradus, is a red giant located approximately 180 light-years away from Earth in the southern constellation of Dorado.
A gigantic star with remarkable activity
R Doradus is nearly 350 times larger than our Sun and exhibits a spectacular phenomenon on its surface. Despite its colossal size, scientists predict that R Doradus will eventually resemble our Sun and undergo similar stellar evolution, transforming into a red giant as it nears the end of its life cycle in about five billion years.
“This is the first time the bubbling surface of a real star can be shown in such a way,” said Wouter Vlemmings, the study’s lead author, in a statement. “We had never expected the data to be of such high quality that we could see so many details of the convection on the stellar surface,” he added.
Convection bubbles captured by ALMA
These extraordinary convection bubbles were captured using the Atacama Large Millimeter/submillimeter Array (ALMA). While astronomers have previously detected convection bubbles on other stars, ALMA’s observations have provided an unprecedented level of detail, allowing scientists to track the motion of these bubbles for the first time.
“Convection creates the beautiful granular structure seen on the surface of our Sun, but it is hard to see on other stars,” explained co-author Theo Khouri. “With ALMA, we have now been able to not only directly see convective granules – with a size 75 times the size of our Sun! – but also measure how fast they move for the first time,” he added.
The findings, published in the prestigious journal Nature, reveal giant, hot bubbles of gas appearing and disappearing at high speeds beneath R Doradus’ surface. The astronomers have, for the first time, observed the rapid movement of these convective granules, which on R Doradus, exhibit a one-month cycle—faster than the convection observed on our Sun.
“It is spectacular that we can now directly image the details on the surface of stars so far away, and observe physics that until now was mostly only observable in our Sun,” said Behzad Bojnodi Arbab, a graduate researcher at Chalmers and a study participant.
This remarkable achievement not only enhances our understanding of stellar behavior but also raises intriguing questions about the nature of stars and their evolution, providing a fascinating glimpse into the complexities of our universe.