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Postby dale blue » Sat Jun 05, 2010 7:50 pm

hi,could you tell me if right ascention(ra) 0hrs starts in the northern sky throughout the year and does it move.
can you tell the time of night by ra?dave.
dale blue
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RE: ra

Postby sftonkin » Sun Jun 06, 2010 12:30 pm

Hmm -- I'm not sure you understand what RA is. 0h RA is that half of a great circle (called the equinoctial colure) that extends from the north celestial pole (NCP) to the SCP via the intersection of the ecliptic and the celestial equator (aka the First Point of Aries -- FPA).

My[url=http://astunit.com/tutorials/positional.htm] tutorial on positional astronomy[/url] may help.
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