Carnegie Astrometric Planet Search

Data Analysis Team Members:

Alan Boss, Alycia Weinberger, Sandra Keiser, Tri Astraatmadja, Serge Dieterich, Maggie Thompson (DTM)
Guillem Anglada-Escude (Queen Mary College, London, United Kingdom)
Berry Holl (University of Geneva, Geneva, Switzerland)

Operational Team Members:

Alan Boss, Alycia Weinberger, Sandra Keiser, Michael Acierno, Tri Astraatmadja, Maggie Thompson (DTM)
Ian Thompson, Christoph Birk (Carnegie Observatories)

Development Team Members:

Alan Boss, Alycia Weinberger (DTM)
Guillem Anglada-Escude (Queen Mary College, London, United Kingdom)
George Gatewood (Allegheny Observatory)
Steven Majewski, Richard Patterson (University of Virginia)
Ian Thompson, Greg Burley, Christoph Birk (Carnegie Observatories)

CAPSCam 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.]

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.