Wednesday, 20 February 2013

Partial lightcurve for 2012 DA14

On the night after closest approach, when the apparent motion had slowed down to around 15"/min and magnitude faded to about +15, three hours of photometric observations were obtained, the diagram below indicating that just a part of the overall rotational lightcurve had been captured, showing a rise to magnitude +14.3R, followed by a fall to +15.9R.

Radar results for 2012 DA14 obtained from NASA's Goldstone facility and qualified by Dr. Lance Benner on MPML indicate a rotation period of "probably somewhat longer than 8 hours".

2012 DA14: 3 hours of lightcurve covering 2013 Feb. 16th 21:10 UT  - 17th 00:11 UT
PPMXL catalogue used for reductions, error bars derived from measured S/Nr are shown

Update 20/2/2013 20:35UT: A much more complete lightcurve by Bruce Gary from Hereford Arizona Observatory (G95)  can be seen here, covering about 10 hours of observing, yielding a rotation period of just over 9 hours.

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