Free Astronomy Magazine July-August 2023

39 JULY-AUGUST 2023 The team succeeded in capturing a superflare with continuous, high temporal resolution observations. Data analysis shows that the super- flare originated with a phenome- non known as a prominence erup- tion. Calculating the velocity of the eruption requires making some as- sumptions about aspects that aren’t directly observably, but even the most conservative estimates far ex- ceed the escape velocity of the star (347 km/s), indicating that the promi- nence eruption was capable of breaking free of the star’s gravity and developing into Coronal Mass Ejections (CMEs). The prominence eruption was also one of the most massive ever observed, carrying tril- lions of tons of material. A team of Japanese astronomers used simultaneous ground-based and space-based observations to capture a more complete picture of a superflare on a star. The observed flare started with a very massive, high-velocity prominence eruption. These results give us a better idea of how superflares and stellar promi- nence eruptions occur. This is an artist’s impression of the superflare observed on one of the stars in the V1355 Orionis binary star system. The binary companion star is visible in the background on the right. [NAOJ] !