TAOS Detected a Predicted Occultation by (286) Iclea
with Three Telescopes Running in Synchronous Mode
(6 Feb. 2006)
TAOS A
TAOS B
TAOS D
The star TYC 076200961 (MV = 11.83) was occulted by
the asteroid (286) Iclea (MV = 14.0, diameter = 97 km)
at around 12:35 6th Feb. 2006 (UTC).
This event was
predicted by Dr. Sato
with a maximal occultation duration around 7.6 seconds.
Its shadow was expected to pass through the central part of Taiwan
where the TAOS site is located.
Using a special zipper mode operation,
three working TAOS telescopes are able to identify this event clearly
while running in synchronous mode.
The above pictures were derived from the raw data
taken by TAOS A, TAOS B,
which is 6 meters apart from each other, and
TAOS D
(within 100 meter range of A and B) telescopes.
A zipper dark frame was subtracted.
The time interval is 0.25 seconds between the readout of two row blocks.
(These pictures were rotated by 90 degrees.
Therefore, a "row block" is now in the vertical direction.)
Each row block has a physical size of 2048 by 76 pixels originally
in this observation.
Only 100 by 76 pixels are shown in the above pictures.
An occultation lasted for 23 row blocks
(23x76 pixels in the horizontal direction) is visible.
The red bars indicate the position of the target star in our zipper mode image.
Two yellow bars mark roughly the starting (the left ones)
and the ending (the right ones) of this event.
Raw zipper images were saved as a single file every 8 seconds (32 row blocks).
The central (vertical) black line in a tiled image
is the artificial boundary of two files.
The same row block in sequence (starting from the left) does not have to
associate with the same time tag.
A time-calibrated result is better obtained from the
light curve plot.
All telescopes were controlled remotely from National Cental University
and were running in synchronous mode by Kiwi Zhang.
The number of telescopes used, the brightness of the target star,
and the new tracking code developed last summer
provide new features of the TAOS system
comparing to our previous two events.
It, again, shows us the power of TAOS zipper mode operation
and the capability of controlling more than one telescope
with TAOS control software.
TAOS is a collaboration between Academia Sinica (Taiwan),
National Central University (Taiwan),
Lawrence Livermore National Laboratory (US),
Yonsei University (Korea),
and other individuals from
Harvard-Smithsonian Center for Astrophysics (US),
University of Pennsylvenia (US),
UC Berkeley (US), NASA Ames (US),
SLAC (US), University of Arizona (US).
Prediction
This event was predicted by
Dr. Sato, Isao
(Nakano Star Gazers Club).
GIF Movie
GIF animations of this occultation observed by
TAOS A,
TAOS B, and
TAOS D.
The total time included in these GIF animations is 16 seconds
for each telescope.
Notice that these images are not rotated as it was in the above images.
Therefore, the row block stretched in the horizontal direction
as is illustrated by the direction of the streaks of some bright stars.
(prepared by Andrew Wang, ASIAA)
Light Curves
- Light curves (from Andrew Wang):
P.S. Counts is normalized to 155 ms.
- Light curves (from Kiwi Zhang):
- 40 minutes
(PDF,
JPG)
- one minute around the event
(PDF,
JPG)
- Light curves (from Dae-Won Kim, Yonsei University):
TAOS homepage
Last Updated by S. K. King February 9, 2006
