No. 49: Jan-Feb 1987
Speaking of transient events, such as the optical bursters (above), the apparent recent color change of Sirius is now receiving theoretical attention. (See SF#43.) Sirius seems to have been a bright red star in medieval times, whereas now it shines with bluish-white light. The latest theory is that Sirius B recently experienced a thermonuclear runaway event.
(Bruhweiler, Frederick C., et al; "The Historical Record for Sirius: Evidence for a White-Dwarf Thermonuclear Runaway?" Nature, 324:235, 1986.)
Comment. Such an event should have been visible from earth, but we know of no such observation on record.