A hint of gamma rays.

A hint of gamma rays 

The various physical processes going on in and behind the exploding front of supernova 1987A produce radiation over most of the electromagnetic spectrum. As the front expands and thins out, it becomes transparent to more and more wavelengths. The only major part of the spectrum not yet seen is gamma rays, but participants at the meeting heard a report that may hint at an imminent discovery of them.

Gamma rays are the "hardest' (most energetic and highest frequency) of electromagnetic radiation. They are produced in processes of nucleosynthesis that ought to go on in the supernova. Because supernovas are the only place in the universe where physicists can imagine the conditions necessary to form the heaviest elements, they are eagerly awaiting evidence from the supernova that will confirm the theory.

A given nuclear process produces gamma rays of a particular energy. One such energy is 847 kilo-electron-volts. The Solar Maximum Mission satellite (SMM), which was originally put up to observe the sun, has been watching for gamma rays from the supernova since the explosion began last February. Steven Matz of the Naval Research Laboratory in Washington, D.C., reported that SMM saw a slight rise above background noise in the intensity of gamma rays of this energy at the very end (in September) of the latest period for which they have analyzed their data. He emphasized that no claim of discovery of gamma rays was yet being made, but the observers will watch the data for the next period to see whether the hint becomes a discovery.