Census of the Kuiper-Belt Objects - The Taiwan-America Occultation Survey (TAOS)

AbstractMore than two hundred transneptunian Kuiper-Belt Objects (KBOs) have so far been identified. Because of their large distances from the Sun, and their intrinsically small sizes, only the largest members (diameters more than 100 km) can be observed by direct imaging with large telescopes. Even smaller KBOs, though expected to be more numerous on theoretical grounds, cannot be seen directly unless they happen to block out the light from background stars. The Taiwan-America Occultation Survey (TAOS) project is a collaboration among the Lawrence Livermore Laboratory (USA), Academia Sinica, National Central University (both of Taiwan), and other institutes, that aims to measure the frequency of such chance stellar occultations, and thereby conduct the census of the Kuiper-Belt population down to a few kilometer sizes. An array of robotic telescopes are being set up in central Taiwan to monitor the brightness variation of several thousand stars at a rate of a few Hz. Observations will be operated in a synchronized and coincidence mode, so the sequence and timing of any candidate occultation event can be recorded and distinguished against a false detection. The full survey is expected to start in the fall of 2000.

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The Taiwan-America Occultation Survey for Kuiper Belt Objects

International Astronomical Union Colloquium ◽

10.1017/s0252921100078994 ◽

2001 ◽

Vol 183 ◽

pp. 253-258

Author(s):

Sun-Kun King

Keyword(s):

Direct Detection ◽

Kuiper Belt ◽

Ccd Camera ◽

Fourth Power ◽

False Alarms ◽

Wide Field ◽

Kuiper Belt Objects ◽

Stellar Astronomy ◽

Robotic Telescopes ◽

Central Taiwan

AbstractThe purpose of the TAOS project is to directly measure the number of Kuiper Belt Objects (KBOs) down to the typical size of cometary nuclei (a few km). In contrast to the direct detection of reflected light from a KBO by a large telescope where its brightness falls off roughly as the fourth power of its distance to the sun, an occultation survey relies on the light from the background stars thus is much less sensitive to that distance. The probability of such occultation events is so low that we will need to conduct 100 billion measurements per year in order to detect the ten to four thousand occultation events expected. Three small (20 inch), fast (f/1.9), wide-field (3 square degrees) robotic telescopes, equipped with a 2,048 × 2,048 CCD camera, are being deployed in central Taiwan. They will automatically monitor 3,000 stars every clear night for several years and operate in a coincidence mode so that the sequence and timing of a possible occultation event can be distinguished from false alarms. More telescopes on a north-south baseline so as to measure the size of an occultating KBO may be later added into the telescope array. We also anticipate a lot of byproducts on stellar astronomy based on the large amount (10,000 giga-bytes/year) of photometry data to be generated by TAOS.

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Fast CCD Photometry in the Taiwan-America Occultation Survey

Open Astronomy ◽

10.1515/astro-2017-0082 ◽

2003 ◽

Vol 12 (4) ◽

Author(s):

W. P. Chen ◽

Z. W. Zhang ◽

S. K. King ◽

C. Alcock ◽

Y. I. Byun ◽

...

Keyword(s):

Kuiper Belt ◽

Sampling Rate ◽

Ccd Camera ◽

Ccd Photometry ◽

Ccd Imaging ◽

Stellar Photometry ◽

Analysis Scheme ◽

Type Variable ◽

Set Up ◽

Central Taiwan

AbstractWe 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.

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