T Coronae Borealis

T Coronae Borealis is a binary star and a recurrent nova about 3,000 light-years (920 parsecs) away in the constellationCorona Borealis. T Coronae Borealis is its variable-star designation and the name most frequently used in the astronomical literature, but it also has the official proper name Blaze Star. The system was first observed in outburst in1866 by John Birmingham, but had been observed earlier in as a 10thmagnitude star. It may have been observed in1217 and in1787 as well. In February1946, the flare-up was discovered independently by three observers: the Soviet amateur astronomer A. S. Kamenchuk, the 15-year-old schoolboy Michael Woodman from Wales, and the British variable star observer N. F. H. Knight. This led to the theory that the star flares every 80years with the next nova expected to occur before 2027. Its apparent magnitude varies between 2.0 in outburst and 10.8 in quiescence, representing about a 3300-fold change in brightness. T Coronae Borealis enters solar conjunction and becomes hidden by the Sun's glare in late November.