I understand that main sequence/white-dwarf binary systems are the cause of type Ia supernovae. Is it possible that the Sirius A/B system could go supernova? The white dwarf, Sirius B, is an unusually large dwarf, about 1 solar-mass. While Sirius A is a 2.1 solar-mass main sequence star. The orbital radius is rather large, about 20au. So it seems there would be no ability of material to be sucked from A to B to make it go supernova. But some seem to think that there is another body in orbit with them that has perturbed Sirius B in the past. What would happen if this caused Sirius B to fall into Sirius A? Would there be a supernova in that case? Thanks.