Pairs of stars might drive parcels of gas together and produce gamma rays
S. Wiessinger/NASA Goddard Space Flight Center
New observations might explain why explosions on three nearby white dwarfs, the cores of dead stars, recently belched out gamma rays (SN: 9/20/14, p. 15). The discovery stumped researchers because no one expected this type of eruption, called a nova, to produce such high-energy light.
Novas are thermonuclear blasts on the surfaces of white dwarfs that have gorged themselves on gas from a companion star. To spit out gamma rays, the blast needs to run into more gas, which is absent around typical novas.
Laura Chomiuk, an astrophysicist at Michigan State University in East Lansing, and colleagues monitored radio waves from one of the three novas last year. As the white dwarf and its companion danced around each other, gas blown out between the stars slowed down while gas leaving their poles sped away, Chomiuk’s team