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Re: Venus ex-meridian
From: Jeremy C
Date: 2011 Jan 16, 23:11 EST
From: Jeremy C
Date: 2011 Jan 16, 23:11 EST
Excellent! I am glad that I'm not the only one taking advantage
of a bright Venus.
Jeremy
In a message dated 1/17/2011 3:00:20 A.M. Central Asia Standard Time,
fedeastro.rossi@libero.it writes:
This morning, after weeks of cloudy weather, a beautiful sun was shining
over Genoa, Italy so I took my 1940 Plath sextant, reached the shore (44
25.5 N 8 48.8 E by GPS) which is only 5 minutes away by feet and took my
first Venus sight in full daylight.
I preset the sextant to the precomputed altitude and, after some tries,
I finally spotted Venus with its phase clearly visible through my 3.5 x
scope.
Here's what I got:
08 50 31 UT Hs 26 37,1 I.C. = 0 elevation 4 meters
I worked out the sight using the haversine method and Norie's tables (as
I usually like to do) and found an intercept of 0.8 miles towards (which
I consider not too bad considering the task of collimating Venus with a
bright horizon), azimuth being 189,5 by ABC tables.
Since the hour angle was within ex-meridian limits (8 52.0 W), I decided
to work the sight as an ex-meridian and found that the position line
passes through 44 24,5 N 8 48,8 E (in good accordance with the "normal"
position, but only 0.2 miles towards Venus). Anyway, this ex-meridian
reduction took almost the same time as the haversine did.......