We conducted a search for occultations of bright stars by Kuiper Belt Objects ( KBOs ) to estimate the density of sub-km KBOs in the sky .
We report here the first results of this occultation survey of the outer solar system conducted in June 2007 and June/July 2008 at the MMT Observatory using Megacam , the large MMT optical imager .
We used Megacam in a novel shutterless continuous–readout mode to achieve high precision photometry at 200 Hz .
We present an analysis of 220 star hours at signal-to-noise ratio of 25 or greater .
The survey efficiency is greater than 10 % for occultations by KBOs of diameter d \geq 0.7 ~ { } \mathrm { km } , and we report no detections in our dataset .
We set a new 95 % confidence level upper limit for the surface density \Sigma _ { N } ( d ) of KBOs larger than 1 km : \Sigma _ { N } ( d \geq 1 ~ { } \mathrm { km } ) ~ { } \leq~ { } 2.0 \times 10 ^ { 8 } ~ { } \mathrm { deg } ^ { -2 } , and for KBOs larger than 0.7 km \Sigma _ { N } ( d \geq 0.7 ~ { } \mathrm { km } ) ~ { } \leq~ { } 4.8 \times 10 ^ { 8 } ~ { } \mathrm { deg } ^ { % -2 } .