On the morning of June 6th, Venus is going to transit, i.e., the
planet is going to pass in front of Sun. The previous transit was in
July of 2004, but the next one will take about a century later. Venus
will start to transit around 1:10 (EEST; current time zone for Turkey)
in the morning, hence Sun and Venus will be below horizon at that
time. The transit will be in progress as the Sun rises, and will end
at about 7:50.
To see the transit for the longest possible duration, you need to be
at a location where you have a clear view of the eastern horizon, on
the morning of June 6th. The Sun will rise at about 5:30 in Istanbul,
but for every angle degree that the horizon is above the horizontal,
it will remain out of sight for additional four minutes.
To observe the transit safely, you must use a solar filter. Such
filters are given as promotions with this month's issues of TUBITAK's
magazines "Bilim ve Teknik" and "Bilim Çocuk". Similar filters were
distributed by many agencies in the past for Solar eclipses etc., and
can also be used in this instance. Do not look at the Sun with naked
eye under any circumstance! Such an action will not only prevent you
to see Venus at all, but may also cause permanent damage to your eyes.
Apart from a filter, you do not need a telescope or binoculars to
observe the transit. If you want to use a telescope or binoculars,
then you must use appropriate solar filters for your equipment; the
filters mentioned above will not be suitable.
You can get more detailed info from
(English) http://eclipse.gsfc.nasa.gov/OH/transit12.html
(Turkish) http://www.tug.tubitak.gov.tr/vt_2012.php