Venus Transit

[Gianni Ferrari]

As Peter Ranfagni has already written, on  June 8 th 2004, some Italian astronomers and dialists have tried to observe (for the first time) the phenomenon of the transit of Venus in some of the “camera obscura” sundials that we have in Italy.  The phenomenon has been observed in S. Maria del Fiore in Florence (Ranfagni, Ferrari + hundreds  persons), in  Rome in S. Maria degli Angeli (Catamo and Lucarini) and in Palermo (in the cathedral).  Perhaps also other observers have seen the transit in such a way.    I remind  that the possibility to observe the transit of Venus in a “camera obscura” sundial is an event really rare : the transits happen only at long intervals;  the event must be  visible in a place in which there is one of these sundials;  the event must happens in a period  near the noon; finally the sky must be clear!  :-)   Yesterday in Italy all these conditions have been favourable even if the period of visibility of the phenomenon has been very short.   The times  ( in UT) for Florence have been the followings:              10h 55m (around) the image of the Sun has become visible on the steps of a side chapel               10h 59m (around)   the complete image was on the floor of the church              11h 04m   III contact               11h 16m(around) last instant in which I personally have been able to see the image of Venus              11h 24m   IV contact    In Florence the committee “Astronomy in the Cathedral" that has organized the event (Opera di Santa Maria del Fiore, Astrophysical Observatory of Arcetri, Institute of History of the Science) had arranged to darken partly the great windows of the tambour of the dome and to go out the artificial illumination during the period of observation.    In the last 2700 years the condition to observe the event happened only in the years 303, 546, 1040 and yesterday June 8th 2004.    The next favourable transit will be on  June 11th 2247     The next transit of Mercury - more frequent but more difficult to observe, also it never observed in a sundial - can be seen only  on  May 9 th 2016 : you all are invited  to make preparations to come in Italy!    :-)   A regard  Gianni Ferrari 44° 39' N      10° 55' E Mailto : [EMAIL PROTECTED]