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Old 07-01-2013, 08:28 PM
gary
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gary is offline
 
Join Date: Apr 2005
Location: Mt. Kuring-Gai
Posts: 5,999
It is important for observers to note that since this object is passing so close to
Earth, the effects of parallax become significant, so you should compute an
ephemeris based on your observing city or town.
http://ssd.jpl.nasa.gov/horizons.cgi#top

For example, at 17:00 UTC, there is a 22 arc minute (over one third of a degree)
difference in apparent RA/Dec from Glen's location in Casino, NSW compared to
an observer in Sydney, even though the distance between Casino and Sydney is
only 588km.
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