FW: (SNES) Transit of Mercury on Wednesday

["Pilotstar" <pilotstar@mindspring.com>]

-----Original Message-----
From: snegazers-owner@brainiac.com
[mailto:snegazers-owner@brainiac.com]On Behalf Of Andy and Barry
Sent: Saturday, May 03, 2003 9:09 PM
To: snegazers@brainiac.com
Cc: SNE Gazers
Subject: Re: (SNES) Transit of Mercury on Wednesday


Sounds like a solar filter is needed.

Stars in your eyes,
Barry



Barry,

You can view the Mercury transit by projecting a large image of the sun
through your scope's eyepiece onto a piece of white cardboard held on a
makeshift tripod or other support. Have the carboard tilted so it is at a 90
degree angle to the projected beam emenating from your eyepiece. Focus the
sun's image on the cardboard using your scope's focusser so you can clearly
see sunspots and the black disk of Mercury on the sun. You can vary the
distance of the cardboard from your eyepiece until you get the proper
size/brightness of the projected solar image.

WARNING:  Under NO cicumstances attempt to view the sun directly through
your telescope without a proper solar filter. Exposed negative film,
sunglasses, etc. are NOT proper filters. Instead,  view the sun's projected
image on the carboard viewing screen ONLY. Ensure no one attempts direct
viewing of the sun through the eyepiece or looks directly at the projected
beam. BEFORE you set up your telescope, cover (cap) your finderscope and
leave it covered at all times. Do NOT use your finderscope to locate the
sun, instead point your scope by eye looking along the scope's tube at the
sun: slowly move your scope around until the shadow of your scope is of
smallest size and you can see the sun's image projected from the eyepiece on
a handheld small piece of carboard.

AGAIN: NEVER LOOK DIRECTLY AT THE SUN THROUGH YOUR EYEPIECE!!


For best results use older eyepieces that do not have cemented lenses. I use
a low-power eyepiece to first locate the sun and identify Mercury in my
scope, then switch to a higher power for a better view of Mercury. At higher
powers only part of the sun's disk will be visible, so be sure this visible
portion is where Mercury is!! You can identify Mercury as a sharp black dot,
as opposed to the larger not-as- sharp sunspots. You will have to keep
adjusting your scope due to the Earth's rotation. I put my equatorial scope
on clock drive which simplifies things for me.

If you have a camera, you can take pictures of the sun's projected image on
the carboard. Try to get as close to the carboard as possible--make sure
your camera can focus at the distance the camera is from the cardboar
image--and try to have the camera as close as a 90 degree angle to the
cardboard as possible. Also ensure the carboard is as close as possible to a
90 degree angle to the eyepiece. Time and record your pictures to the
nearest second. For example: Picture 1 at 06:15:20; Picture 2 at 06:17:20,
etc.


I have observed and photographed two Mercury Transits using the techniques
above--you can do the same.

Ernie
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