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It is a rare circumstance
when the Moon with an age of less than 24 hours is well placed
in the daytime sky, on a clear day and with a nearby bright planet
for checking the setting circles and focus occurs. Such was the
case yesterday at lunchtime here in Arizona, and I took advantage
of it despite the thin cirrus haze which was reducing contrast
near the suns glow.
Special precautions
are always taken when shooting so near the Sun in the daytime,
and an eyepiece is never installed - only the ccd camera for
making these observations. To find the moon, I first pointed
the scope at the Sun, with an appropriate over the aperture solar
filter installed. Then set the manual setting circles on the
Suns coordinates. You cant use the digital circles (NGC Max)
on the Sun, it wont let you use it as a reference. Next, I dialed
in Venus, which was 50 degrees east and centered up the planet,
set the camaras focus and then was ready to find the thin moon.
I next pull out the
camera, and point to the coordinates of the moons disk. After
double checking that the Sun is not in the field with a white
card over the focuser, I put in the camera being careful not
to move the pre set focus. On the computer, I set the gamma to
a very low value - like 10, and adjusted the brightness to be
about 3/4 histogram. And sure enough - I could see its super
faint arc in the center of the field! The contast was so low,
being near the Sun and with the haze, but I took 1200 video frames
with my DMK51 CCD camera on two fields it took to cover the full
moon arc.
Here is the result,
it quite dim but you can see the broken arc of a 0.4% moon that
is only 15 hours old.
Here is the setup with
the 10 inch which shows the "Moon Raker" tube extension,
which I made from chromed bubble plastic sheet stock from ACE
hardware and some velcro straps. This blocks the sunlight from
entering the tube when imaging so close to the Sun in the Daytime.
It was made specifically for thin moon projects like this.
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