T Pyxdis is a recurrent nova that has erupted in brightness more times than any other known nova. Normally seen at around magnitude 14, on May 2nd 1902 its ‘first’ outburst was captured on photographic plates taken at Harvard. It reached maximum brightness of mag 7.3. Research showed that in fact it was captured on photographic plates in 1890.
T Pyx has gone nova in 1890, 1902, 1920, 1944, and 1966. It is now long overdue for another increase in brightness and certainly a star worth keeping an eye on. The 1920 event appears to be the brightest with that star reaching magnitude 6.4.
Novae are binary systems with two stars orbiting each other, one star which will be cooler than the other has gas pulled off the other hotter star and forms a disc around it, when too much gas is orbiting the second star it this cooler gas falls onto the hotter star and in simple terms the star will sizzle and throw about 0.1% of its mass into space abd cause the star to become brighter.