Researchers May Have Solved a Two-Thousand-Year-Old Stellar Mystery Recorded by Ancient Astronomers

For more than two millennia, astronomers have puzzled over a stellar mystery recorded by some of history’s greatest skywatchers. Hipparchus, Ptolemy, and the Persian astronomer al-Sufi—all separated by more than 1,000 years—each described Theta Eridani as one of the brightest stars in the night sky.