Next message: Frank Reed: "Re: Lunar reference"
Bill you wrote:
"Observation Error
#1 -0.2'
#2 -0.1'
#3 -0.1'
#4 -0.2'
#1 and #2 with neutral-density shade over moon and light green over Venus:
#3 and #4 with neutral-density and light-green shade over moon and light
green over Venus.
I was pretty pleased, but then the separation was only in the upper 15d
range, so relatively easy. I was somewhat surprised all were under."
I don't think you should worry too much about this (that they were all
"under"). These are excellent results, and the fact that they are all negative
values probably means nothing. Considering the weather at the time of those
sights and the low altitude of Venus, you might want to experiment with varying
the temperature during the clearing process to see how much that will
influence the cleared distance. The air has been very thick in the Midwest US
recently! High barometric pressure and Siberian cold guarantees a significant
increase in atmospheric density and therefore refraction.
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
