Benutzer Diskussion:Episcophagus

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Letzter Kommentar: vor 4 Tagen von Episcophagus in Abschnitt Nutation (Astronomie)
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Hello,

I just reverted your Edit in Anthroposophie. "Weltsicht" is correct, and pleas do not set Weblinks in the article. It's only allowed as reference or in the "Weblinks" section.

Kind regards, --46.18.62.65 15:40, 28. Mär. 2018 (CEST)Beantworten

Nutation (Astronomie)

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Hallo Episcophagus,

Hast du die Graphik der Nutation anhand korrekter Jahres-Daten erstellt? Ich frage deshalb, weil das Jahr 2016 unten mit der größten negativen Abweichung (-9,2") der Nutation der Ekliptikschiefe eingezeichnet ist. Wenn die Grafik Datei:Nutation perioden.svg korrekt ist, bedeutet das aber, dass in deiner Grafik unten die Jahre 2020 / 2021 stehen müssten und 2015 müsste links von der Bildmitte sein (-6,8" = Nutation der Länge)? Oder ich habe irgendwas falsch verstanden? ;) MfG

Nutation2015-2033

--Helko Peters (Diskussion) 01:38, 22. Jun. 2024 (CEST)Beantworten

@Helko Peters: The scales are not in celestial or ecliptical longitude and latitude but shows the deviation from the mean pole in arc seconds in the directions of the ecliptical meridian (y-axis) through the mean pole and along the great circle that is perpendicular to the meridian at the mean pole (x-axis) - i.e. the spherical distances in those two directions.
The parallels (except the equator...) are not great circles, and thus you have to multiply the difference in ecliptical longitude with cos 66°34' to get an image that shows the correct outline as seen from the earth (i.e. shows the actual elliptical shape). To get the horisontal scale (x-axis) in arcseconds ecliptical longitude you have to divide +/-5" with cos. 66°34' ≈ 0.4, giving +/-12.5".
The calculations (from JD 2457024, i.e. 2015.01.01, and then on forward in time to 18×365.25 days from that date) are based on
George H. Kaplan, 2005, The IAU Resolutions on Astronomical Reference Systems, Time Scales, and Earth Rotation Models - Explanation and Implementation, United States Naval Observatory Cicular No. 179.
and
Dennis D. McCarthy, 1996, IERS Technical note 21, p36. Only the first 10 sets of arguments given were used for the actual calculations (the remainder gives corrections that are less than 1‰ of the principal nutation and would not show in the figure).
Episcophagus (Diskussion) 09:14, 22. Jun. 2024 (CEST)Beantworten