2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12140Gamma-ray bursts are sudden releases of energy that for a duration of a few seconds outshine even huge galaxies. 30 years after the first detection of a gamma-ray burst their origin remains a mystery. Here I first review the ``old'' problems which have baffled astronomers over decades, and then report on the ``new'' exciting discoveries of afterglow emission at longer wavelengths which have raised more new questions than answered old ones.14 pages, LATEX with memsait.sty, incl. 4 Figs., talk given at the Frascati workshop "Multifrequency behaviour of high energy cosmic sources", Vulcano, May 1997, to appear in Mem. Societa Astron. Italiana; jgreiner@aip.deAstrophysicstext