Stellar close-up
VERY LARGE TELESCOPE, 20 DECEMBER 2017
For the first time, astronomers have been able to directly observe granulation patterns on the surface of a star outside our Solar System. The star is Pi1 Gruis, a red giant with a mass the same as the Sun, but a diameter 350 times larger. Each of its convective cells, or granules, is about 120 million kilometres across; just one granule would stretch from the Sun to beyond Venus.
