This issue’s variable star is U Scorpii. Like our May issue’s target, T Coronae Borealis, U Sco is a recurrent nova. (If you have the May issue handy, give it a quick re-read.) U Sco has a period of 10.6 (±1.6) years between explosions, and it turns out the next one is due around now. However, Brad Schaffer of Louisiana State University, who predicted the 2010 event, says there are indications it might be early. Let’s hope we’re not too late.
Beyond the nova explosion is the supernova. U Sco, like T CrB, contains a white dwarf that is already close to the 1.4 solar mass limit that it needs before exploding. A survey of the literature suggests that U Sco is possibly the best thermonuclear supernova candidate known, with…