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Old 22-05-2013, 12:29 AM
Rob_K
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Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,158
You might find it wise to get personalised ephemerides from JPL (set observer location) because there is a bit of parallax going on even now. Tonight I did a (very rough) image of the asteroid but the faint dot that was showing didn't seem to exactly match the ephemeris position for that time. After I re-ran the ephemeris with my location set, the position given was spot-on.

I put together a graphic (attached) showing the geocentric position versus the position viewed from my location, using DSS plates with crosshairs generated at the ephemeris positions. Time was 8:24 pm (10:24 UT). Fair difference and it will increase as the lump of rock nears Earth.

The asteroid is currently near the zenith in southern skies immediately after dark, handy with a big bright Moon!

Cheers -
Attached Thumbnails
Click for full-size image (JPL ephemeris positions, 10-24, 21 May 2013 UT.jpg)
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