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42 lines
1.0 KiB
42 lines
1.0 KiB
15 years ago
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<sect2 id="calc-julian">
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<title>Julian Day module</title>
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<indexterm><primary>Tools</primary>
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<secondary>Astrocalculator</secondary>
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<tertiary>Julian Day module</tertiary>
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</indexterm>
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<screenshot>
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<screeninfo>
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The Julian Day calculator module
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</screeninfo>
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<mediaobject>
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<imageobject>
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<imagedata fileref="calc-julian.png" format="PNG"/>
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</imageobject>
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<textobject>
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<phrase>Julian Day</phrase>
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</textobject>
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</mediaobject>
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</screenshot>
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<para>
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This module converts between the calendar date, the <link
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linkend="ai-julianday">Julian Day</link>, and the
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<firstterm>Modified Julian Day</firstterm>. The Modified Julian Day
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is simply equal to the Julian Day - 2,400,000.5.
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</para><para>
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To use the module, select which of the three dates will be the input,
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and then fill in its value. Then press the
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<guibutton>Compute</guibutton> button, and the corresponding values for
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the other two date systems will be displayed.
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</para>
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<tip>
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<para>Exercise:</para>
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<para>
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What calendar date does MJD = 0.0 correspond to?
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</para>
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</tip>
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</sect2>
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