Stars don’t usually evolve fast enough for humans to notice them change within one lifetime. Even a hundred lifetimes won’t do—astronomical processes are just too slow. But not always. There are some phases of stellar evolution that happen quickly, and when they do, they can be tracked. A new paper posted to ArXiv last week uses astronomical observations found in ancient Roman texts, medieval astronomical logs, and manuscripts from China’s Han Dynasty to trace the recent evolution of several bright stars, including red supergiant Antares, and Betelgeuse: one of the most dynamic stars in our sky. With observations from across the historical record, the paper suggests that Betelgeuse may have just recently passed through the Hertzsprung gap, the transitional phase between a main sequence star and its current classification as a red supergiant.
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Source: Phys.org