Black Widow Evolution

Black widows are millisecond pulsars with low-mass companions (~2% the mass of the sun) on short orbits of several hours. When the first black widow was discovered in 1988, it was proposed that its companion is the remnant of a main sequence star that had been evaporated by the pulsar’s high energy radiation. I will present new observations from the last decade that challenge this picture, and discuss how the growing population of black widows can be explained consistently.