Scientists predicted this star would explode. Its bucked expectations.

For centuries, stargazers have watched a new star light up in the sky. Just days later, it vanishes.

Today we call the star system responsible T Coronae Borealis, "T CrB" for short, or the "Blaze Star." It fires up around every 80 years, and NASA noted that astronomers expected to see the star appear around the summer of 2024. It's now 2025. What gives?

This repeating event — occurring 3,000 light-years from Earth — is triggered by two interacting, orbiting stars. An Earth-sized star...