Wait, aren't those for cloudy nights?? ;-)
Richard N.
? I collected a set of the centerfold
-----Original Message-----
From: Jim Van Nuland <jvn@No-Spam>
To: The Astronomy Connection <sf-bay-tac@No-Spam>
Sent: Sun, 2 Mar 2008 9:46 pm
Subject: Re: [TAC] Astro project
richardn22@No-Spam wrote:?
> Other than a telescope, what have you built to aid or improve?
> your night out observing??
?
? A spectacle lens that fits over the top of my 20mm Erfle eyepiece, to correct for astigmatism and near-sightedness. It allows me to see the full 75 degree field. Slip it off and the scope is in focus for most people.?
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? A switchable red/white flashlight, in 1974 when such thing was not marketed. Rechargeable from 110vac or 12vdc.?
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? I collected a set of the centerfold all-sky charts from a year of Sky & Telescope magazine, and made up a table to show which one to use during both day and night hours. Later I found a planisphere that properly shows the southern sky, and use that instead. (Dave Chander's "The Night Sky")?
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? An occulting mask to search for faint companions of double stars, such as Sirius (succeeded). Also used it to spot 7 moons of Saturn, when the ring was edge-on. Used it to find one moon of Mars.?
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? A pole-finding reticle for my 50mm finder. It has a circle whose radius is the distance from Polaris to the pole, and radial tic marks every two hours, built by Kevin Medlock to my design. Must be scaled to the focal length of the finder's objective lens. Includes cross hairs with degree marks.?
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? Installed a tiny LED to edge-illuminate the above reticle. Cleverly hid the electric wires.?
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? A computer program to calculate the RA, Dec, Alt, Az, and elongation of planets and some bright stars. Includes lunar phase, Julian vs. Gregorian date conversions, etc. Later ported from IBM mainframe to the IBM Personal Computer. I still use it occasionally.?
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? A set of wood blocks in 1, 2, and 4-inch thickness, to level my telescope. Drilled a shallow hole in each so the scope's feet will not slide off.?
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? An adjustable north foot for setting elevation.?
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-- Jim Van Nuland, San Jose (California) Astronomical Association?
<http://www.svpal.org/~jvn/index.htm> JVN's web site?
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--
GSSP Web Page updated 2/25: http://www.goldenstatestarparty.org
Who's observing where? - http://observers.org/OI-calendar/
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Received on Sun Mar 02 23:11:56 2008