18 August 2005

Finders for Some Assembly Required

I keep rolling this over in my mind and have decided that it has to be done. It was so easy to locate things with a plastic wrap tube (recommended over paper towels and toilet paper because it is stiffer) that I think I will go that route for Some Assembly Required. But I will use PVC pipe in stead of the pasteboard tube. For nighttime viewing I will just use a 6" length of tubing that I should be able to get from Home Depot. I will lay it into the finder shoe that comes attached to the scope. Then I will loop a bight of thin black cord over it and pass it through the secondary cage. At the other end I will place an s-hook and an adjustable loop to tighten the cord and hold the tube in place. The cord passing through the secondary will not obstruct the light path any more than the screws holding the finder shoe in place already do. I was amazed at how much of the aperture had to be blocked before there was a noticeable drop in image brightness. For solar observing I will take a similar length of pipe and get end caps for it. In the front end I will drill a small hole and leave it unobstructed. For the back end I will drill a larger hole and attach to the inside of the cap a frosted material of some kind. When the sun is lined up in the finder the image of it should be projected from the pinhole in front onto the frosted material at the rear and be visible from behind the scope. I guess I could also cut a hole in the side of the tube and paint the inside of the plug white so you could stand at the eyepiece and look through the side of the tube for the projected sun image on the bottom cap.

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Observing Location	Met Oval There is so much light pollution here from street lights, fountain floodlights and the Moon that I am seeing few stars tonight.
Observational Period	2045-2215 EDT (- 30 min for dinner)
Atmospheric Conditions	It was a little cooler than usual and a little humid so I could have used a long sleeve t-shirt of windbreaker. There was a light breeze that kept the tree limbs in motion. The sky around the moon was lit up with haze and there was a very slight boiling on the limb of the moon. Transparency Good Seeing Very Good
Instruments	Canon 15x50 Image Stabilized binocular - Charlie
Observing Party	Charlie Ridgway

Target	Iridium 11 ∓ Iridium 20
Constellation	Cam
Category	Satellites
Time	18Aug05; 2056 EDT
Comments	These two Iridiums flared within a minute of each other. I saw one but don't know which one for sure. I suspect I saw the second one since I didn't see any following it and had not been looking in that location previously. Satellite Iridium 11 Iridium 20 Time 2056 EDT 2057 EDT Altitude 24° 23° Azimuth 352° 352° Magnitude -3.8m -1.9m I was looking at 352° Magnetic when the flares were due to occur by my watch. I didn't see anything and was turning away assuming they had occurred behind an apartment building rather than just over its roof and saw a flare in the neighborhood of 16° Magnetic. I had gone to Heavens-Above.com to see what I might see tonight but either their site is down or my new OS and browser software are configured so that I can't see it. So I had to use CalSky. I didn't have time to read the legend that says they give azimuths in "degrees counting from geographic North clockwise to the East direction" which I take to mean from True North. I used the NOAA National Geophysical Data Center (NGDC) magnetic declination estimator to determine what the declination for the oval was today ( it changes by 0° 2' E/year) and used it to compute the magnetic bearing where the flare should have occurred and it looked to me like it occurred about 11° farther E. True [true] 352° Variation (Declination) [virgins] 13° 20' W Magnetic [make] 005° 20' Deviation [dull] unknown Compass [company] 005° 20' [add whiskey] I need to compare the Heavens-Above predictions which are referenced to an unknown system, to those on CalSky and see if I can figure out what frame of reference Heavens-Above uses. Both programs know the longitude and latitude of my observing site and provide event listings in my local time zone so I think it is strange that they would provide compass bearings in degrees True which most people would not be able to measure with their Cracker Jack compass.

Target	Moon
Constellation	Cap
Category	Lunar
Time	18Aug05; 2155 EDT
Comments	I had to wait for the moon to rise above the trees and apartment buildings. It looks full tonight but the northeast quadrant still looks like it has a flat spot on the limb. There is strong ray structure visible out of Tycho and Copernicus. Plato and Billy are very dark as is Endymion. Features in descending order of darkness as seen through my binocular: Name Type Darkest Plato crater Billy crater Endymion crater Mare Crisium sea Mare Tranquillitatis sea Mare FecunditatisM.td sea Mare Serenitatis sea Lightest Binocular focus was noticed to shift as denser and less dense patches of haze moved in front of the moon.