FTN discovers “slowest rotating NEO”!
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Following on from last year’s discovery of the fastest rotating Near Earth Object, 2008 HJ, the FT NEO Programme has found what is currently the slowest rotating small NEO.
The discovery was made by Richard Miles, co-ordinator of the FT programme and Director of the Asteroids and Remote Planets Section of the British Astronomical Association, after observations obtained by himself and 6 sets of observers: Kingsley School, Paulet High School, the Thomas Aveling School, TU-Darmstadt and Simon Langton Grammar following an observing alert sent out on June 10 by Alison Tripp.
The observations revealed that this object has a probable rotation period of 14.64 hours, which makes it the SLOWEST known rotator for objects around this size range or smaller. It rotates more than 1,000 times more slowly than last year's record breaker, 2008 HJ.
“We were lucky weather-wise in that there were four consecutive clear nights on Maui, which enabled the rotation rate to be tied down fairly accurately” says Richard. “However, the photometric analysis was a major undertaking and was made possible by my using one extra observing session, this time on the Faulkes Telescope South. Using the other 'scope in the southern hemisphere really helped”. “Not a bad result considering the object is only about 70 meters across and was almost 10 times the distance of the Moon from the Earth during most of the observing runs. On June 9-10 it was also only about 20-30 degrees away from a 93-97% illuminated Moon in the sky, which made life difficult” concludes Richard.
In another “first” for FT, Richard made use of a new observing methodology developed by Brian Warner which enables the brightness and colors of ensembles of stars to be determined with fair accuracy (+/-0.02 mag) by using the J and J-K data obtained by the 2MASS survey; probably the most useful homogeneous 'all-sky' source of photometric data which exists.
Image: the lightcurve of asteroid 2009LE, obtained using FTN observations by Richard Miles (BAA) and 6 FT users (Kingsley School, Paulet High School, Thomas Aveling School, TU-Darmstadt and Simon Langton Grammar).
