[in chinese]
A Census of the Newly Discovered Home of Comets!
Taiwan American Occultation Survey of Kuiper
Belt Objects (KBO) in the Outer Solar System
More than sixty small planetary bodies with radii >100 km have recently been
detected beyond Neptune using large telescopes.
Pluto and its satellite Charon are probably the largest members of this family.
The purpose of the TAOS project is to measure directly the number of these KBOs
down to the typical size of cometary nuclei (a few km).
The adjacent figure illustrates how we propose to detect KBO.
When a KBO moves in between the earth and a distant star
it will block the starlight momentarily.
A telescope monitoring the starlight will thus see it blinking.
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 such occultation events expected.
The large range in this estimate reflects our ignorance
in how to extrapolate from large KBOs to small ones.
Evidently, there is an urgent need to conduct a census.
Three small (20 inch) fast (f/1.9) wide-field (2 square degrees)
robotic telescopes equipped with 2,048 x 2,048 CCD cameras will be
operated in a coincidence mode
to reduce the false alarm rate down to 10-11
so that the sequence and timing of the three separate blinkings can be used
to distinguish real events from false alarms.
TAOS will increase our knowledge about the Kuiper Belt,
the home of most short period comets that return to the inner solar
system every few years.
This knowledge will help us to understand the formation and evolution of comets
in the early solar system as well as to estimate their flux of
impacting our home planet.
Lawrence Livermore National Laboratory (through its Institute of Geophysics
and Planetary Physics), National Central University (Institute of Astronomy),
and Academia Sinica (Institute of Earth Sciences and Institute of
Astronomy and Astrophysics) will each contribute one telescope.
The three partners will work together to set up the automatic observatory
on peaks at 3,000 m elevation in or near the Yu-Shan (Jade Mountain)
National Park in Taiwan.
The current plan calls for beginning routine observation at Lulin
by the year 2003.
Yonsei University (South Korea) contributes a fourth telescope in 2002.
The four robotic telescopes will automatically monitor 3,000 stars
every clear night for several years,
consult among themselves to reject false events,
notify us via telecommunication when a real event is found.
Follow up observations using large telescopes at major observatories
around the globe attempting to detect the reflected sun light from the KBO,
hence its orbit and distance, are being organized.
We also anticipate a lot of byproducts on stellar astronomy based on
the large (10,000 giga-bytes/year) photometry data bank to be generated by TAOS.
Home page of TAOS
TAOS homepage