Kuiper Belt Object Occultations : Expected Rates , False Positives , and Survey Design

A novel method of generating artificial scintillation noise is developed and used to evaluate occulta-tion rates and false positive rates for surveys probing the Kuiper Belt with the method of serendipitous stellar occultations. A thorough examination of survey design shows that: (1) diffraction-dominated occultations are critically (Nyquist) sampled at a rate of 2 Fsu −1 , corresponding to 40 s −1 for objects at 40 AU, (2) occultation detection rates are maximized when targets are observed at solar opposition, (3) Main Belt Asteroids will produce occultations lightcurves identical to those of Kuiper Belt Objects if target stars are observed at solar elongations of: 116 • ε 125 • , or 131 • ε 141 • , and (4) genuine KBO occultations are likely to be so rare that a detection threshold of 7 − 8σ should be adopted to ensure that viable candidate events can be disentangled from false positives. A method of detecting km-sized Kuiper Belt Objects (KBOs) is that of serendipitous stellar occulta-tions (SSO). Km-sized KBOs are too faint to be observed directly, but can, in theory, be detected indirectly. The passage of a KBO through the line of sight to a background star will produce a characteristic perturbation in the observed stellar photometric time series , serendipitously revealing the presence of the oc-culter. The method was originally proposed by Bailey occultation searches have been used to probe the population of the trans-Neptunian region. In this paper, we evaluate a variety of issues which are central to planning, and performing a KBO occultation survey. The methods we've used in our analyses are presented in Section 2, and results for the issues examined are presented in Section 3. Much of the work presented herein is based on the planting and recovery of occultation profiles in synthetic photometric time series. Great care must be taken to reproduce the atmospheric scintillation properties of real photometric data, and we begin in Section 2.2 by developing a method of generating artificial time series to reproduce the properties of real time series in both the time domain and the frequency domain. The SSO method was examined in the context of the Kuiper Belt (Roques & Moncuquet 2000, hereafter R&M) before a break in the KBO size distribution had been identified (Bernstein et al. 2004) or confirmed (Fuentes & Holman 2008; Fraser & Kavelaars 2009). In Section 3.1, we present updated KBO occultation rate estimates …