See sun spots,
the transit of venus...featured
stars only come out at night, right? WRONG!
Build a DIY telescope that
at stars in the daytime and study the closest star to Earth safely
during your lunch break!
Why can't I see
the stars during the day time?
a matter of fact, the stars do come out in the day, they are shining in
the sky all the time. It's just that the Sun is so bright we can't see
the faint starlight compared to the brilliance of the Sun's light.
Imagine having a torch with very flat batteries. The torch doesn't seem
to light up at all when you try it out in the sunshine. Try it in a
dark room at night and still glows faintly, we just couldn't notice it
during the day.
the stars are there in the day, but what about the problem of the Sun?
You might think that it is so bright that we'll never see stars in the
day...but you would be forgetting one thing...
Sun is a star, the closest star to our planet. That is why it is so
bright. The other stars we see at night are also suns, some the same
size or bigger than ours. The reason they appear small and dim is
because they are so very far away from us. It's a bit like looking at
car headlights when they are close to you, they look large and bright.
When a car is far off in the distance, the light looks smaller and less
bright even though the size of the headlamps haven't really changed! If
our sun (a star called Sol) has planets going around it, perhaps the
other stars do to....
By building a special attachment for a
telescope, we can safely look at
the Sun, learn about stars, and still get home in time for tea...
need for a safe sun viewer...the Sun Gun
the light from the Sun is so bright and intense we NEVER LOOK AT THE
SUN DIRECTLY THROUGH A TELESCOPE OR BINOCULARS. You will be blinded,
of us have probably projected an image of the sun onto a piece of card
for safe viewing instead. The Sun Gun idea was a modification of this
and an article appeared in Scientific American in 2000. As a Physics
project, the Inglewood High students had to learn about light, lenses,
real and virtual images and levers while trying to apply their
an inexpensive spotting scope is fitted with an adapter at the 2003
A piece of pipe
that has a suitable diameter so that it will slide over the eyepiece is
pushed through a hole cut into the bottom of an old plastic paint
The pipe is
fixed to the base of the container via a screw-threaded flange. The
interior is painted matt black with spray paint and left to dry.
The lid of the
container has its entire centre cut out leaving only the rim providing
a 1cm flat lip once it is pushed back onto the main body of the
A sheet of
"RediDraw" Draughtsmans tracing film (polyester) makes an excellent and
inexpensive projector screen.
Cut to an
appropriate size it can be temporarily fastened to the flat 1cm lip
using adhesive gum, velcro, etc, so it can be removed for safe storage
or easily replaced if damaged.
to the front of the telescope result in much sharper images and more
detail can be seen than our initial attempts and digital photography
show below (can you see the Sun spots on the left?).
better quality telescope also provides better images though the scope
we used was quite satisfactory for the simple observations and
demonstrations that most teachers will undertake. A piece of card cut as a
large square about 50cm across placed over the front of the telescope
(cut a hole in the centre of the card the diameter of the telescope
tube) provides some shade that gives the eye better contrast when
looking at the image projected at the back.
The tripod set up was OK
but was prone to wind wobble and any bumps of the leg as students
crowded around. A
permanent mount could be erected in a convenient location in a school.
This would provide more stable arrangement than our simple tripod would
permit. Regular observations of the Sun and Sunspots could be
undertaken by students and perhaps the period of rotation could be
The sun will move across
the projector in proportion to the magnification used. I used a
mid-range magnification so I only had to swing the telescope around to
follow the sun every few minutes.
A sturdy post to attach the telescope to
is required and a sun tracking motorised mount could be made (eg, use
to LDR’s and measure resistance between them; the motor moves
until both show the same resistance). You just have to point the
telescope in the right direction once, then take photos or record video
is also possible to use this as a solar observatory during the transit
New Plymouth "The Art Shop" stocks the polyester film we used but you
might like to try other materials such as thermal drape lining. I do
not recommend paper since the fibres are easily visible in bright light!
the experts for more information while visiting the New Plymouth
observatory. The members of the
Astronomical Society hold open nights every Tuesday night between