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A further improvement defines a fictitious mean Sun that moves with constant speed along the celestial equator ; the speed is the same as the average speed of the real Sun , but this removes the variation over a year as the Earth moves along its orbit around the Sun ( due to both its velocity and its axial tilt ) .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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