A short time ago, some astronomers used the ALMA telescope in Chile to take pictures of a nearby red giant star called R Doradus. What they found revealed a cosmic wonder: huge bubbles, 75 times more massive than our Sun, emanating from the surface of the star. While our Sun dominates our solar system—holding 99.8% of its mass—it pales in contrast with stars such as R Doradus (350 times wider) yet with similar mass.
R Doradus is around 180 light-years away and currently at the red giant stage where stars find themselves nearing the end of their lives; having exhausted their fuel supply, they bloat dramatically. Our own Sun is expected to attain this in about 5 billion years. This expansion and ultimate demise are attended by convection so intense: huge bubbling-hot gas rises from the star’s core up to its surfaces where it then cools down before sinking back down a visual reminiscent description of a cosmic lava lamp.
For the first time, astronomers have been able to see the bubbling surface of a real star in such detail. Some of these convective bubbles, or granules, span a diameter 75 times larger than the Sun, moving in a monthly cycle. This movement is faster than anticipated, raising questions about how convection changes as a star ages.
The data’s clarity astounded lead researcher Wouter Vlemmings, who noted that this degree of information had never been recorded before. Scientists are learning more about the future and location of our Sun in the universe by examining stars like R Doradus.
This ground-breaking study, which was published in Nature, offers a fresh look at how aging stars function and sheds light on the dynamic processes that form the universe and the history of stars.
