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Sun, distances and self-confidence
From: Alexandre Eremenko
Date: 2005 Jun 7, 12:40 -0500
From: Alexandre Eremenko
Date: 2005 Jun 7, 12:40 -0500
I made few more Sun observations with artificial horizon from the window of my Kiel appartment. Here are the results: Coordinates: 54d19.7'N, 10d08.8'E, IC=+0.6', watch 1 sec fast. May 29, naked eye: GMT 5:01:10 30d00.8' 5:03:32 30d40.7' 5:04:46 31d01.2' Reduced alt: 15d29.9'. Computed alt 15d30.2' (this was naked eye!) May 29, inverting scope: 5:08:23 32d03.1' 5:10:20 32d35.8' 5:12:45 33d17.0' 5:13:49 33d34.4' Reduced alt: 16d39.4' Computed alt 16d39.3' (Error +0.1') May 29, Galileo scope: 5:16:05 34d12.6' 5:17:31 34d37.5' 5:18:34 34d55.0' Reduced alt: 17d 30.8' Computed alt: 17d30.9' (Error -0.1') June 7, inverting scope (my favorite) 4:57:45 30d28.4' 4:59:35 30d58.4' 5:01:15 31d27.1' Reduced alt: 15d41.9' Computed alt: 15d41.8' (Error +0.1) I am pleased both with the magnitude of the errors and their random sign (so they are not systematic). It seems from these data that my sextant is indeed in good order after Freiberger's tune up. Or, as Fred suggested once, that I finally gained some self-confidence. BUT: On May 31 I observed the distance between Vega and Altair, from the same window, with the same sextant, and with the same self-confidence, and in reasonably good weather... and got a long and consistent series... which was 1.5' off! I used both my scopes. And this distance is not large... in the same range as my Sun measurements. I am at complete loss. Is there indeed some bug inside my sextant's trommel? The bug which sleeps in the morning hours and wakes up at night? Or should I ask an oculist to check my night vision? Alex.