These are the best and most detailed images of a star other than the Sun to date, according to the researchers. The images provide answers to what our sun may look like in the future, when it is transformed into a red giant.
– It is spectacular, says Behzad Bojnodi Arbab, PhD student at Chalmers University of Technology in Gothenburg, who participated in the study.
The new images were shown at Chalmers University of Technology in Gothenburg on Wednesday. What the astronomers managed to document with a high-tech telescope in Chile is the star R Doradus. A red giant star with a diameter about 350 times that of the Sun, located about 180 light-years away in the constellation Swordfish.
– 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 could mainly only be seen on our sun, says Behzad Bojnodi Arbab, at Chalmers, who participated in the study.
The researchers at Chalmers are behind the study of the new images that were published on Wednesday.
Shows the surface of the star
It is the first time astronomers have taken images of a star other than the Sun in sufficient detail to track the movement of bubbling gas on its surface.
Stars produce energy in their interior through nuclear fusion. This energy can be transported towards the surface of the star in huge and hot gas bubbles which then cool down and sink – like a lava lamp, the research team writes in a press release. The phenomenon is called convection.
The researchers are almost lyrical, even if the images can be perceived by a layman as blurry and unclear.
– This is the first time that the bubbling surface of a real star can be shown in such a way, says Wouter Vlemmings, professor and lead author of the study.
Revealing what our sun might look like
The star R Doradus is similar to our Sun in many ways, except that it is much larger and older. According to the researchers, the star is likely to be similar in appearance to our own sun in five billion years, when the sun transforms into a red giant. But to draw conclusions about how our sun will function in billions of years, even better images of other stars are required.
What is clear is that the massive gas bubbles on R Doradus develop in a cycle that lasts about a month, which is faster than scientists expected when compared to the Sun.
– We do not yet know what is the reason for the difference. It appears that convection changes as a star ages in ways we don’t yet understand. Observations like those now being made of R Doradus help us understand how stars like the Sun behave, even when they grow as cool, large and convective as R Doradus, says Wouter Vlemmings.