We have received a set of photometric data taken by Marek Kozubal and
Ronald Dantowitz at the Clay Center Observatory, Dexter School, MA,
spanning about 2 hours. In addition to a dramatic trend of about 2.5
magnitudes brightening, the data show a very clear periodicity of about 0.9
magnitude amplitude and a simple period of 49 seconds, or a double period
of 98 seconds. Thus Richard's analysis is just about right, within his
stated error estimate. After de-trending the data and examining a longer
time series, it appears that the variation is not simply periodic, but
instead the object appears to be in a non-principal axis spin state, or
"tumbling". There are a few other tumbling super-fast rotators, so this is
not a unique case. It will take a bit more time for a careful analysis,
since aspect is changing as fast as the brightness, so there may need to be
a "de-trending" of the time series applied as well.

Alan Harris and Brian Warner


At 05:26 PM 10/7/2008, RICHARD MILES wrote:
>Gustavo,
>
>A most excellent animation.
>
>Folk might want to watch the object flashing brighter and fainter.
>It appears to do this 26 times in a periodic fashion.
>
> From the field shown, I estimate the sequence lasts some 1380 seconds.
>If the variations are due to rotational modulation of the light, the object
>must therefore rotate every 106 +/-8 seconds or so.
>That would make it the 4th fastest rotator that we know of amongst the
>asteroid community!

*******************************************************************
Alan W. Harris
Senior Research Scientist
Space Science Institute
4603 Orange Knoll Ave. Phone: 818-790-8291
La Canada, CA 91011-3364 email: awharris@...
*******************************************************************