The stars aren’t fixed and unchanging, unlike what many ancient people thought. Once in a while, a star appears where there wasn’t one before, and then it fades away in a matter of days or weeks.

The earliest record of such a “guest star,” named so by ancient Chinese astronomers, is a star that suddenly appeared in skies around the world on July 4, 1054. It quickly brightened, becoming visible even during the day for the next 23 days.

Astronomers in Japan, China and the Middle East observed this event, as did the Anasazi in what is now New Mexico.

In the second half of 2024, a nova explosion in the star system called T Coronae Borealis, or T CrB, will once again be visible to people on Earth. T CrB will appear 1,500 times brighter than usual, but it won’t be as spectacular as the event in 1054.