Carnegie Astrometric Planet Search
Team Members:
Alan Boss, Alycia Weinberger, Guillem Anglada-Escude (DTM)
George Gatewood (Allegheny Observatory)
Steven Majewski, Richard Patterson (University of Virginia)
Stuart Shaklan, Steven Pravdo (Jet Propulsion Laboratory)
Ian Thompson, Greg Burley, Christoph Birk (Carnegie Observatories)
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CAPSCam-S is shown mounted at the Cassegrain focus of the 2.5m
du Pont telescope at Las Campanas Observatory in Chile.
Astrometric Planet Search on the du Pont Telescope:
We have undertaken a new search for Jupiter-like planets in orbit around
nearby stars. Using the 2.5-m du Pont telescope located at Carnegie's
Las Campanas Observatory in Chile, we are searching for gas giant planets
similar to Jupiter by the astrometric method. In this method, the wobble
of the host star's position on the sky as it orbits around the center of
mass of the star-planet system is measured with high accuracy. Knowing the
mass of the star then allows the true mass of the planet, as well as its
orbital parameters (including the semi-major axis, eccentricity, and
inclination), to be determined. Our observations of the M7 cluster with
the Tek5 camera on the du Pont imply that astrometric accuracies of 0.25
milliarcsec per hour may be achievable, sufficient to detect a Solar
System analogue at 5 pc with a signal-to-noise ratio of 4. We have
built a specialized astrometric camera, the Carnegie
Astrometric Planet Search (CAPS) camera, with support from the NSF and
CIW. The heart of the CAPS camera is a Teledyne Hawaii-2RG HyViSI
array, with the camera's design being optimized for high accuracy
astrometry of red dwarf stars. Our preliminary estimate of the
accuracy achieved with CAPSCam supports the M7 cluster estimate,
at least for a single night of data. We will follow 100 nearby
low mass stars, principally late M, L, and T dwarfs, for 10
years or more, in order to detect Jupiter-mass planets with orbital
periods long enough to permit the existence of habitable, Earth-like
planets on shorter-period orbits. [Click on the picture of
the du Pont dome below for a link to the Las Campanas Observatory.]
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Astrometric Planet Search on the Hooker Telescope:
In addition to the du Pont planet search, we are undertaking a
northern hemisphere astrometric planet search on the 2.5m Hooker Telescope
of the Mount Wilson Observatory, in California. This search is
a continuation of the STEPS astrometric planet search by Steve Pravdo
and Stuart Shaklan of JPL. Pravdo and Shaklan will lead the northern
planet search on the 100" Hooker telescope, which was built by
the Carnegie Institution in 1917, and was the world's largest
telescope until the Palomar 200" telescope began operations in 1948.
The northern planet search is made possible by using the engineering
grade Teledyne Hawaii-2RG device to build a second astrometric
camera, CAPSCam-N, identical to the original camera (now called
CAPSCam-S) on the du Pont in Chile. CAPSCam-N will begin operations
at Mount Wilson in 2008, and will search for gas giant planets in
orbit around M dwarf stars in the northern hemisphere. [Click on the
picture of CAPSCam-N below for a link to the Mount Wilson Observatory.]
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Teledyne Array:
Teledyne's (Rockwell Scientific) 2048 x 2048 HAWAII-2RG is the state of-the-art
multiplexer for advanced astronomy and space telescope applications.
Providing the ability to choose detector material (HgCdTe or Silicon PIN)
allows the user access to any band from 350 nm to 5.3 micron. Selectable
number of outputs (1, 4 or 32) and userselectable scan directions provide
complete flexibility in data acquisition. The ``Guide Mode'' provides a
programmable window which may be read out continuously at up to 5MHz pixel
rate for stable tracking of guide stars. The readout is designed to allow
interleaved readout of the guide window and the full frame science data.
The Hawaii-2RG HyViSI array thus allows relatively bright target stars to
be read out at a much higher cadence than the relatively
faint reference stars.
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CAPSCam-S:
Click on the image below for a link to a directory containing
numerous images of CAPSCam-S:
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