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Unformatted text preview: Models of the Sky - Celestial S phere Sometimes a degree is pretty big and you need to measure an angle that is much smaller than a degree, so you need to use a smaller unit of measure (sort of like the way an inch is a smaller unit of a foot). To make life easier, we can divide one degree into smaller units known as minutes . To be precise, 1º = 60' (the dash stands for minutes). Sometimes using minutes is not enough; even smaller units are needed. We can divide each minute up into (you guessed it) seconds . Of course, the division is 1' = 60 " (two dashes signify seconds). For those with nothing better to do, you might note that 1º = 3600". An object's declination can be given very precisely as, for example, -34º 27' 41''. A lot of times astronomers have to keep track of time (not that we ever have any dates or something like that, but just to keep track of events in the sky). If astronomers need to talk about minutes and seconds, like as in units of time, how can we know that they are talking about time...
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This note was uploaded on 12/15/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.
- Fall '10