Trans-Neptunian Objects
Photo credit: Oscar Saa, CTIO

The Solar System contains thousands of rocky and icy objects with diameters ranging from a few tens of meters to hundreds of kilometers. Many of these orbit the Sun at distances beyond Neptune. These Trans-Neptunian Objects are difficult to detect due to their small sizes and large distances from the Sun. A promising technique is to search for stellar occultations. When a KBO passes between the Earth and a distant star, it casts a shadow which can be detected if it passes over a telescope. These are rare and fleeting events and require monitoring of thousands of background stars with millisecond time resolution. No unambiguous events have yet been seen.

Thomas Pfrommer and I have begun a program using the LZT to search for TNOs. Our technique is to operate the CCD in drift-scan mode at a very high scan rate. This produces star trails which form a record of the star's brightness as a function of time. Thousands of star trails can be obtained each night and searched for the signatures of occultations. Unfortunately, our primary CCD failed soon after the start of observations. We are working to install a smaller backup camera so the program can continue.