A Tale Of Two Stars: Early Results From The Type Ia Supernova SN2011fe (Part I)

Those watching the sky in August may have heard the news that a new star had appeared: the type Ia supernova PTF11kly (later rechristened SN2011fe) had touched off in M101, the Pinwheel Galaxy, a bare 6.4 Mpc away; close enough that for a brief period the supernova was visible to anyone with a good pair of binoculars. As the closest recent type Ia observed, astronomers were able to use it to place the first direct observational constraints on the progenitor of a type Ia supernova.