Joseph Michael Giammarco

TAOS: The Taiwanese–American Occultation Survey

The Taiwanese–American Occultation Survey (TAOS) seeks to determinethe number and size spectrum for small (∼3 km) bodies in the KuiperBelt. This will be accomplished by searching for the brief occultations of brightstars (R∼14) by these objects. We have designed and built a specialpurpose photometric monitoring system for this purpose. TAOS comprisesfour 50 cm telescopes, each equipped with a 2048×2048 pixel CCDcamera, in a compact array located in the central highlands of Taiwan. TAOSwill monitor up to 3,000 stars at 5 Hz. The system will go into scientificoperation at the end of 003.

Search for Small Trans-Neptunian Objects by the TAOS Project

The Taiwan-America Occultation Survey (TAOS) aims to determine the number of small icy bodies in the outer reach of the Solar System by means of stellar occultation. An array of 4 robotic small (D=0.5 m), wide-field (f/1.9) telescopes have been installed at Lulin Observatory in Taiwan to simultaneously monitor some thousand of stars for such rare occultation events. Because a typical occultation event by a TNO a few km across will last for only a fraction of a second, fast photometry is necessary. A special CCD readout scheme has been devised to allow for stellar photometry taken a few times per second. Effective analysis pipelines have been developed to process stellar light curves and to correlate any possible flux changes among all telescopes. A few billion photometric measurements have been collected since the routine survey began in early 2005. Our preliminary result of a very low detection rate suggests a deficit of small TNOs down to a few km size, consistent with the extrapolation of some recent studies of larger (30-100 km) TNOs.

Fast CCD Photometry in the Taiwan-America Occultation Survey

Abstract We describe the efforts of the Taiwan-America Occultation Survey (TAOS) project to develop a data acquisition and analysis scheme for fast CCD imaging photometry. The TAOS project aims to conduct a census of the Kuiper-belt objects (KBOs) by detecting chance stellar occultation events by these small bodies in the outer reach of the solar system. An array of telescopes, each with fast optics (f/2) of 0.5 m aperture and equipped with a 2K CCD camera (3 square degrees FOV), have been set up in central Taiwan to monitor a couple thousand stars simultaneously. By reading out the CCD chip sequentially a few rows of pixels at a time (pause-and-shift), it is possible to achieve stellar photometry with a sampling rate up to several hertz. Here we report how such a setup has been used to observe the SX Phoenicis type variable CY Aqr to illustrate the potential usefulness of the TAOS database in stellar variability studies.