Transit of Venus - 8 June 2004
![[TPSAVC Site map]](tps_map.jpg)
Starts just
after 3pm, Sydney time (other
locations). The full disk of Venus should be visible
as a tiny black dot on the Sun by 3.30pm and will be partly across
the Sun at sunset. The whole event takes about 6 hours so we in Sydney
will miss more than half of it. :(
Always supervise children who are interested in
this rare event. Never, ever
look at
the sun directly or through an amateur telescope or binoculars
(do not trust a solar filter
on amateur
equipment - especially
eye-piece filters).
Note that welding
goggles and the like are
useless because
Venus is so small, compared with the Sun's disk. If you have very good
eyes and can easily see craters on the Moon unaided then you might be
able to spot Venus crossing the Sun. The rest of us will need to use a
telescope to project the image (see below) or watch the event on the
Internet.
Similarly, sunglasses
are useless for this event and sunglasses
will not protect the eyes from
permanent damage.
One safe way to use a small telescope is
to project
the image onto a screen using a 90 degree mirror (see pictures
below) - then several people can observe the event without fighting
over the telescope. Practice this technique by observing sun spots
before the event - this will also help you distinguish between sunspots
and Venus.
If you can set up in or next to a building (remember the Sun
will be low in the western sky in Sydney) you may be able to project a
much larger image than the one pictured onto a screen (or ceiling) in a
darkened area.
Aim the telescope by observing its shadow - the whole of the white
tube will go
into the shadow of the cowl, when the telescope is pointing at the sun.
Use fine
adjustment until the image appears in focus on the screen. Do not try
to use the
finderscope - it will damage your eyes!
Unless you are lucky enough to have a motor drive telescope will you need to adjust the aim of the telescope every few minutes to follow the Sun as it sets in the Western sky (as well as magnifying the image, telescopes magnify motion). It is much easier to make the adjustment before the Sun's image moves out of the field of view.
DANGER: NEVER LOOK THROUGH AN AMATEUR TELESCOPE OR BINOCULARS AT THE SUN
CAUTION: THIS METHOD IS FOR A SMALL REFRACTOR TELESCOPE AS SHOWN. THERE IS A RISK THAT TELESCOPE COMPONENTS COULD BE DAMAGED BY THE CONCENTRATED RAYS OF THE SUN.
IT IS NOT RECOMMENDED FOR OBSERVING AN ECLIPSE OF THE SUN
This is the set up showing the Sun's image projected at right
angles, onto a white screen. The telescope has a 60mm main lens. With
larger telescopes it may be advisable to partly cover the end of the
tube to cut out some of the sun's light.
This shot shows a good observing position. I could easily see some
sunspots from here. Note that the finderscope has been removed (or
cover it up) -
although small it can still easily damage the eye by concentrating the
Sun's rays.
Here is another view of the set up. If the surrounds are relatively
dark, like this room, then the screen can be moved further away to
obtain a larger image.
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