A wide-field CCD survey for Centaurs and Kuiper Belt objects

A modified Baker-Nunn camera was used to conduct a wide-field survey of 1428 deg² of sky near the ecliptic in search of bright Kuiper Belt objects and Centaurs. This area is an order of magnitude larger than any previously published CCD survey for Centaurs and Kuiper Belt objects. No new objects brighter than red magnitude m_R = 18.8 and moving at a rate 1″ to 20″ hr^-1 were discovered, although one previously discovered Centaur, 1997 CU₂₆ (Chariklo), was serendipitously detected. The parameters of the survey were characterized using both visual and automated techniques. From this survey, the empirical projected surface density of Centaurs was found to be Σ_C(m_R ≤ 18.8) = 7.8^+16.0 _-6.6 × 10^-4 deg^-2, and we found a projected surface density 3 σ upper confidence limit for Kuiper Belt objects of Σ_K(m_R ≤ 18.8) < 4.1 × 10^-3 deg^-2. We discuss the current state of the cumulative luminosity functions of both Centaurs and Kuiper Belt objects. Through a Monte Carlo simulation we show that the size distribution of Centaurs is consistent with a q ∼ 4 differential power law, similar to the size distribution of the parent Kuiper Belt objects. The Centaur population is of order 1 × 10⁷ (radius ≥ 1 km), assuming a geometric albedo of 0.04. We predict about 100 Centaurs larger than 50 km in radius, of which only four are presently known. The current total mass of the Centaurs is about 10^-4 M_⊕. No dust clouds were detected resulting from Kuiper Belt object collisions, placing a 3 σ upper limit of fewer than 600 collisionally produced clouds of m_R < 18.8 per year.