  Two major problems, still associated with the SN1987A, are: a) the signals
observed with the gravitational waves detectors, b) the duration of the
collapse. Indeed, a) the sensitivity of the gravitational wave detectors seems
to be small for detecting gravitational waves and, b) while some experimental
data indicate a duration of order of hours, most theories assume that the
collapse develops in a few seconds. Since recent data of the X-ray NuSTAR
satellite show a clear evidence of an asymmetric collapse, we have revisited
the experimental data recorded by the underground and gravitational wave
detectors running during the SN1987A. New evidence is shown that con rms
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 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. This result indicates that also Kamiokande detected neutrinos at
the Mont Blanc time, and these interactions were not identi ed because not
grouped in a burst.
