From the 389 2002 OGLE-III observations of Galactic Bulge microlensing events we select 321 that are well described by a point-source point-lens lightcurve model .
From this sample we identify n = 1 event , 2002-BLG-055 , which we regard as a strong planetary lensing candidate , and another , 2002-BLG-140 , which is a possible candidate .
If each of the 321 lens stars has 1 planet with a mass ratio q = m / M = 10 ^ { -3 } and orbit radius a = R _ { E } , the Einstein ring radius , analysis of detection efficiencies indicates that 14 planets should have been detectable with \Delta \chi ^ { 2 } > 25 .
Assuming our candidate is due to planetary lensing , then the abundance of planets with q = 10 ^ { -3 } and a = R _ { E } is n _ { p } \approx n / 14 = 7 % .
Conversion to physical units ( M _ { Jup } , and AU ) gives the abundance of ‘ cool Jupiters ’ ( m \approx { M } _ { Jup } , a \approx 4 AU ) per lens star as n _ { p } \approx n / 5.5 = 18 % .
The detection probability scales roughly with q and ( \Delta \chi ^ { 2 } ) ^ { -1 / 2 } , and drops off from a peak at a \approx 4 AU like a Gaussian with a dispersion of 0.4 dex .