OSSOS. XVII. An upper limit on the number of distant planetary objects in the Solar System

Beyond the giant planets there is a collection of bodies left over from epoch planet formation. The objects that are just beyond Neptune more easily detected than those journey hundreds au away; all such highly eccentric have been observed inside 150 au. We interested here in population Pluto to Mars-sized were almost certainly present early Solar System, some which may now be stranded distant System. Using data Outer System Origins Survey (OSSOS), covers ~167 square degrees down r ~25, we searched for 300 using rarely used search technique. To find created catalogues sources stationary (to level astronomical seeing) three images taken 2 h. then ‘stationary’ not days/weeks/months before and after. Although other phenomena (e.g. supernovae) discovered, no slow moving object was found. From null detection survey simulator, obtain model-dependent 95% upper limit ~1000 on number ‘planetary’ (with absolute magnitudes, Hr, <2) our knowledge this first published scale show if small Mars-scale still despite being brighter they escaped surveys due their rates motion.