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Old 26-11-2009, 05:57 PM
astro744
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Join Date: Apr 2007
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Quote:
Originally Posted by troypiggo View Post
But what is the first 5h you're adding to the 19h for LST? Seems like you're adding 5h twice, I understand one of them would be Orion's RA, but what's the other?
Just think of it in 24hr clock terms (24-19 = 5). The first 5hr brings you to 24/0hrs LST which = 00hrs RA on the meridian. Add another 5hr and Orion is up high.

LST is now just after 21hrs so add 3 to get to 24/00 and then add the RA of the object in question (approx 5 for Orion). In 3hrs time the LST is 24/00 so any objects with an RA of 00 will be on the meridian. Approx 5hrs later again will be Orion.
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