Supernova 1987A, 30 Years Later

Most supernova theories state that this phenomenon lasts for a few seconds and ends with a big final explosion. However, these theories do not take into account several experimental results obtained with neutrino and gravitational wave detectors during the explosion of SN 1987A, the only supernova observed in a nearby galaxy in modern age. According to these experimental results the phenomenon is much more complex that envisaged by current theories, and has a duration of several hours. Since recent data of the X-ray NASA Satellite NuSTAR show a clear evidence of an asymmetric collapse, we have revisited the experimental data recorded by some underground and gravitational wave detectors running at the time of SN 1987A. New evidence is shown that confirms the previous results, namely that the data recorded by the gravitational wave detectors running in Rome and in Maryland are strongly correlated with the data of both the LSD (Mont Blanc) and the Kamiokande detectors, and that the correlation extends over a long period of time (one or two hours) centered at the Mont Blanc time. In addition, the signals of the GW detectors preceded the signals of the underground detectors by a time of order of one second. This result, obtained by comparing six independent files of data recorded by four different experiments located at intercontinental distances, indicates that also Kamiokande detected neutrinos at theMont Blanc time, but these interactions were not identified because not grouped in a burst. A similar correlation was also found in the data of the underground experiments in Mont Blanc and Baksan.