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Project > TAOS

The Taiwanese-American Occultation Survey (TAOS)/Transneptunian Automated Occultation Survey (TAOS II)

TAOS Website TAOS II Website
Lightcurves of (62) Erato occultation on 2011-01-17. This event was observed from two sites separated some 60 km at Taichung (24:06:48N, 120:39:00E) and Lulin (23:28:07N, 120:52:25E). The time of ingress and egress were (16:37:58.33 - 16:38:02.33UT) and (16:37:57.715 - 16:38:03.115UT) respectively for two sites. The estimated diameter of (62) Erato is 85.2+/-0.9 km.
The light curves derived from the TAOS zipper mode data
Lightcurves of (62) Erato occultation on 2011-01-17. This event was observed from two sites separated some 60 km at Taichung (24:06:48N, 120:39:00E) and Lulin (23:28:07N, 120:52:25E). The time of ingress and egress were (16:37:58.33 - 16:38:02.33UT) and (16:37:57.715 - 16:38:03.115UT) respectively for two sites. The estimated diameter of (62) Erato is 85.2+/-0.9 km.
The lightcurves and estimated diameter of (62) Erato from occultation
Rendering of the three TAOS II telescopes to be installed at San Pedro Mártir Observatory in Baja California, Mexico in 2013. The TAOS II control room is shown on the right. The existing 2.1 meter telescope is shown in the background.
TAOS II at San Pedro Mártir Observatory
Rendering of the three TAOS II telescopes to be installed at San Pedro Mártir Observatory in Baja California, Mexico in 2013. The TAOS II control room is shown on the right. The existing 2.1 meter telescope is shown in the background.
TAOS II at San Pedro Mártir Observatory
Rendering of the three TAOS II telescopes to be installed at San Pedro Mártir Observatory in Baja California, Mexico in 2013. The TAOS II control room is shown on the right. The existing 2.1 meter telescope is shown in the background.
TAOS II at San Pedro Mártir Observatory
Rendering of the three TAOS II telescopes to be installed at San Pedro Mártir Observatory in Baja California, Mexico in 2013. The TAOS II control room is shown on the right. The existing 2.1 meter telescope is shown in the background.
TAOS II at San Pedro Mártir Observatory
Rendering of the three TAOS II telescopes to be installed at San Pedro Mártir Observatory in Baja California, Mexico in 2013. The TAOS II control room is shown on the right. The existing 2.1 meter telescope is shown in the background.
TAOS II at San Pedro Mártir Observatory
TAOS zipper-mode image of the occultation of HIP050525 (mv~8.46mag) by the asteroid (1723) Klemola (mv~15.7mag;D~31km). Each frame is a 0.25 second read out of the field. Some 108 stellar photometric measurements have now been made in this mode. (King et
TAOS zipper-mode image of the occultation of HIP050525 (mv~8.46mag) by the asteroid (1723) Klemola (mv~15.7mag;D~31km)
One of the TAOS 0.5m telescopes in its enclosure
TAOS telescopes
One of the TAOS 0.5m telescopes in its enclosure
TAOS telescopes

The Taiwanese-American Occultation Survey (TAOS) began operations on Lulin Mountain in Chia-Yi in 2005. TAOS is a collaboration between ASIAA, National Central University (NCU), Harvard-Smithosonian Center for Astrophysics, and Yonsei University in South Korea. By monitoring some 1000 stars per night with 2048x2048 CCD cameras, this project searches for the occultation of background stars by Solar system bodies located in the Kuiper Belt.

Because objects in the outer Solar system only shine by reflected sunlight, they are undetectable if their sizes are small and if they are distant. Occultation of background stars is much less sensitive to size, and therefore can extend the detection of these objects to much greater distances in the Solar disk. The utilization of 4 telescopes allows us to discriminate against false detections due to terrestrial events which do not produce coincident events over all telescopes. Our 6-year result sets a very tight constraint on the population of objects larger than 500m in our solar system. This has important implications on how planets might have formed by the collisions of these objects.

From 2013, we have upgraded our camera, with a 1K x 1K frame transfer camera. With the new camera, we can reduce the background noise and enhance the sampling frequency of the observation to 10 Hz. This will enhance the detection efficiency of smell KBOs.

Our detection rate is limited by the performance of the telescopes, and the relatively poor weather and atmospheric conditions at Lulin. We are therefore building the TAOS-2 system, with three new 1.3m diameter telescopes. We have selected the San Pedro de Martir site in Mexico, belonging to the Mexican National Astronomical Observatory, at an elevation of 2800m. TAOS-2 will push the observable limit of our Solar System by an order of magnitude from a distance of 100 to 1000 AU.

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