Which constellation contains the recurrent nova T Coronae Borealis?

T Coronae Borealis is a recurrent nova in the constellation Corona Borealis.

Also called the Blaze Star, T Coronae Borealis is a binary system roughly 3,000 light-years away. Its two stars are a red giant and a white dwarf orbiting each other in about eight months. Gas drawn from the giant accumulates on the white dwarf until a thermonuclear eruption briefly makes the system dramatically brighter.

The star is normally around magnitude 10, too faint for unaided eyes, but its eruptions can make it visible without optical aid. Well-documented outbursts occurred in 1866 and 1946; the 1946 event reached about magnitude 3. The recurrence interval is roughly 80 years, although nova timing is not perfectly predictable.

The name can cause confusion because Corona Borealis means “northern crown,” while Corona Australis is a separate southern constellation. Boötes and Hercules border Corona Borealis, but T Coronae Borealis lies within the northern crown’s official sky boundaries.