Science / Medicine : New Theory Offered on Gamma Ray Bursts

Broken-up comets smashing into collapsed stars may be the trigger for some powerful bursts of high-energy radiation that have mystified astronomers for years, scientists said Wednesday. Strong bursts of gamma rays--extremely shortwave, electromagnetic radiation--appear in space seemingly at random nearly a hundred times a year. Most bursts occur only once, but in the late 1970s, astronomers detected three points that repeatedly flashed radiation--one of which generated nearly 100 bursts between 1979 and 1984.

Astrophysicists have not been able to determine exactly what causes either type of gamma-ray bursts and they are considered one of the most baffling phenomena in the sky. However, a team of French researchers, writing in the scientific journal Nature, proposed a new explanation for repeat “bursters.”

The multiple bursts, which are weaker than their single counterparts, “are due to comets falling onto a magnetized white dwarf” star, theorized J. M. Hameury of the Paris Observatory and his colleagues.