The solar system beyond Neptune

Abstract

We present the results of a deep optical survey for distant solar system objects. An area of 1.2 sq deg of the ecliptic has been imaged to apparent red magnitude 25, resulting in the detection of seven trans-Neptunian objects. These are the first detected members of a trans-Neptunian disk that compries about 35 000 objects larger than 100 km in the 30-50 AU heliocentric distance range. We interpret the new measurements using a set of Monte Carlo models in which the effects of observational bias in the data are taken into account.