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Re: Star - Star Observations
From: George Huxtable
Date: 2010 Mar 11, 11:11 -0000
From: George Huxtable
Date: 2010 Mar 11, 11:11 -0000
Brad wrote-
Now for the fun part, I have two objects already selected.
My location N40d 53.0m W72d 48.0m
GMT 10-March-10 00-57-00
Object 1: RA 6h 45.22m Dec -16.7175
Object 2: RA 9h 27.68m Dec -8.6678
Therefore
D = 40d 21m 12.41s
H1 = 28.63501 d
H2 = 37.80218 d
a1 = 0.03025 d
a2 = 0.02135 d
Corner Cosines
factor 1 = 0.43592
factor 2 = 0.02371
And consequently
d, Corner Cosines = 40d 22m 1.7s
d, Youngs = 40d 24m 45.84s
I find a difference of 2m 44.14s between the two computations. The first
assumption is that I erred again (a too often occurrence IMHO) !
The second assumption is that Young's equations are rigorous while the
corner cosines are only an approximation, therefore a small
difference is to be expected and that Young's equations are the ones to
follow.
Some further commentary would certainly be helpful!
===================
Comment from George.
We need to resolve some serious discrepancies first.
I take the two stars to be Sirius and Alphard.
From 40º53'N, on 10 March 2010, at 0hrs 57 min GMT, I get the predicted
altitude of both stars to be a few minutes less than 32º. Not anything like
the values given by Brad, of Sirius 28.63501º, Alphard 37.8021º. One of us
is doing something wrong. Is it Brad, or is it me?
George.
contact George Huxtable, at george@hux.me.uk
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
