Thursday, 25 February 2016

the sun - Are Wikipedia's sun ecliptic-coordinate formulae accurate?

Assuming that you used the time of 170900 EDT(-4 UT), which is 230900 UT, the following is my math:



Let the Julian Date for 25Mar2016 at 230900, which is 2457473.464583, be set to JD;



Given the formula (on Wikipedia:n = JD - 2451545.0 ), your n is 5928.464583.
Then, taking the second formula ( g = 357.528° + 0.9856003° * n ) you get g=357.528°+5843.0964715441749 = 6200.3544715441749 mod 360 = +80.35447°. Were you to round up this would give +80.4.



Without how you handled your date/time in c++ and your rounding, I would wager that is were the error occurred.

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