T Coronae Borealis (T CrB) recurrent nova system, illustration. This binary system consists of a white dwarf star and a red giant star. The strong gravitational force of the white dwarf pulls gas from the red giant onto its surface, heating it. When the white dwarfs surface reaches over 10 million degrees Celsius a thermonuclear explosion is triggered. The majority of the element lithium found in the universe is produced by novae explosions. T CrB is in the constellation Corona Borealis, approximately 3,000 light-years from Earth.