a nova....
https://ktla.com/news/new-star-could-appear-in-night-sky-in-2024/
Astronomers are predicting a once-in-a-lifetime stargazing opportunity could appear in the northern hemisphere sometime in 2024 – a “new” star in the constellation Corona Borealis, KTLA sister station WBOY reports.
The location of T Coronae Borealis (circled in red) (Wikimedia Commons by PopePompus – Creative Commons Attribution- …
Being millions, if not billions of years old, the star “T Coronae Borealis” (T CrB) isn’t technically new. However, it will soon become visible to the naked eye for the first time in nearly 80 years. But what’s causing it to suddenly become as bright as the North Star?
T CrB is what’s called a recurring nova and is actually a white dwarf in a binary, or two-star, system; its stellar partner is a much larger red giant. According to NASA, as the red giant becomes unstable, it begins to shed its outer layers, which are then sucked up by the gravity of the white dwarf. When T CrB gathers enough stellar material from its neighbor, it lets off a massive explosion, big enough for us to see it 3,000 light-years away here on Earth