  The Dutch Jesuit astronomer Johan Stein published in 1909 a text about the
legend on a papal bull of Pope Callixtus III against the comet of 1456. This
comet happened to be the Halley's one. The original documents, either
chronicles and observations, and coeval testimonies are deeply investigated by
Stein and the falsity of that legend is clearly demonstrated. In the occasion
of the 200 years of the restoration of the Societas Jesu made in 1814 by Pope
Pius VII an Italian edition of the full text of Johan Stein is here presented.
