Optical characterization of the PALM-3000 3388-actuator deformable mirror

We describe the lab characterization of the new 3,388-actuator deformable mirror (DM3388) produced by Xinetics, Inc. for the PALM-3000 adaptive optics (AO) system1 under development by Jet Propulsion Laboratory and Caltech Optical Observatories. This square grid 66-by-66 actuator mirror has the largest number of actuators of any deformable mirror currently available and will enable high-contrast imaging for direct exoplanet imaging science at the Palomar 200" diameter Hale Telescope. We present optical measurements of the powered and unpowered mirror surface, influence functions, linearity of the actuators, and creep of the actuators. We also quantify the effect of changes in humidity

Real-time wavefront control for the PALM-3000 high order adaptive optics system

We present a cost-effective scalable real-time wavefront control architecture based on off-the-shelf graphics processing units hosted in an ultra-low latency, high-bandwidth interconnect PC cluster environment composed of modules written in the component-oriented language of nesC. We demonstrate the architecture is capable of supporting the most computation and memory intensive wavefront reconstruction method (vector-matrix-multiply) at frame rates up to 2 KHz with latency under 250 &mgr;s for the PALM-3000 adaptive optics systems, a state-of-the-art upgrade on the 5.1 meter Hale Telescope that consists of a 64x64 subaperture Shack-Hartmann wavefront sensor and a 3368 active actuator high order deformable mirror in series with a 349 actuator "woofer" DM. This architecture can easily scale up to support larger AO systems at higher rates and lower latency

A Close Companion Search Around L Dwarfs Using Aperture Masking Interferometry and Palomar Laser Guide Star Adaptive Optics

We present a close companion search around 16 known early L dwarfs using aperture masking interferometry with Palomar laser guide star adaptive optics (LGS AO). The use of aperture masking allows the detection of close binaries, corresponding to projected physical separations of 0.6-10.0 AU for the targets of our survey. This survey achieved median contrast limits of ΔK ~ 2.3 for separations between 1.2λ/D-4λ/D and ΔK ~ 1.4 at 2/3λ/D. We present four candidate binaries detected with moderate-to-high confidence (90%-98%). Two have projected physical separations less than 1.5 AU. This may indicate that tight-separation binaries contribute more significantly to the binary fraction than currently assumed, consistent with spectroscopic and photometric overluminosity studies. Ten targets of this survey have previously been observed with the Hubble Space Telescope as part of companion searches. We use the increased resolution of aperture masking to search for close or dim companions that would be obscured by full aperture imaging, finding two candidate binaries. This survey is the first application of aperture masking with LGS AO at Palomar. Several new techniques for the analysis of aperture masking data in the low signal-to-noise regime are explored

PALM-3000 high-order adaptive optics system for Palomar Observatory

Deployed as a multi-user shared facility on the 5.1 meter Hale Telescope at Palomar Observatory, the PALM-3000 highorder upgrade to the successful Palomar Adaptive Optics System will deliver extreme AO correction in the near-infrared, and diffraction-limited images down to visible wavelengths, using both natural and sodium laser guide stars. Wavefront control will be provided by two deformable mirrors, a 3368 active actuator woofer and 349 active actuator tweeter, controlled at up to 3 kHz using an innovative wavefront processor based on a cluster of 17 graphics processing units. A Shack-Hartmann wavefront sensor with selectable pupil sampling will provide high-order wavefront sensing, while an infrared tip/tilt sensor and visible truth wavefront sensor will provide low-order LGS control. Four back-end instruments are planned at first light: the PHARO near-infrared camera/spectrograph, the SWIFT visible light integral field spectrograph, Project 1640, a near-infrared coronagraphic integral field spectrograph, and 888Cam, a high-resolution visible light imager

Design and implementation of the PALM-3000 real-time control system

This paper reflects, from a computational perspective, on the experience gathered in designing and implementing realtime control of the PALM-3000 adaptive optics system currently in operation at the Palomar Observatory. We review the algorithms that serve as functional requirements driving the architecture developed, and describe key design issues and solutions that contributed to the system's low compute-latency. Additionally, we describe an implementation of dense matrix-vector-multiplication for wavefront reconstruction that exceeds 95% of the maximum sustained achievable bandwidth on NVIDIA Geforce 8800GTX GPU

Status of the PALM-3000 high-order adaptive optics system

The PALM-3000 upgrade to the Palomar Adaptive Optics system on the 5.1 meter Hale telescope will deliver extreme adaptive optics correction in near-infrared wavelengths and diffraction-limited images in visible wavelengths. PALM-3000 will use a 3388-actuator tweeter and a 241-actuator woofer deformable mirror, a Shack-Hartmann wavefront sensor with selectable pupil sampling, and an innovative wavefront control computer based on a cluster of 17 graphics processing units to correct wavefront aberrations at scales as fine as 8.1 cm at the telescope pupil using natural guide stars. The system is currently undergoing integration and testing, with deployment at Palomar Observatory planned in early 2011. We present the detailed design of key aspects of the adaptive optics system, and the current status of the deformable mirror characterization, wavefront sensor performance, and testbed activities

Real-time wavefront control for the PALM-3000 high order adaptive optics system

We present a cost-effective scalable real-time wavefront control architecture based on off-the-shelf graphics processing units hosted in an ultra-low latency, high-bandwidth interconnect PC cluster environment composed of modules written in the component-oriented language of nesC. We demonstrate the architecture is capable of supporting the most computation and memory intensive wavefront reconstruction method (vector-matrix-multiply) at frame rates up to 2 KHz with latency under 250 &mgr;s for the PALM-3000 adaptive optics systems, a state-of-the-art upgrade on the 5.1 meter Hale Telescope that consists of a 64x64 subaperture Shack-Hartmann wavefront sensor and a 3368 active actuator high order deformable mirror in series with a 349 actuator "woofer" DM. This architecture can easily scale up to support larger AO systems at higher rates and lower latency

Know The Star, Know the Planet. IV. A Stellar Companion to the Host star of the Eccentric Exoplanet HD 8673b

HD 8673 hosts a massive exoplanet in a highly eccentric orbit (e=0.723). Based on two epochs of speckle interferometry a previous publication identified a candidate stellar companion. We observed HD 8673 multiple times with the 10 m Keck II telescope, the 5 m Hale telescope, the 3.63 m AEOS telescope and the 1.5m Palomar telescope in a variety of filters with the aim of confirming and characterizing the stellar companion. We did not detect the candidate companion, which we now conclude was a false detection, but we did detect a fainter companion. We collected astrometry and photometry of the companion on six epochs in a variety of filters. The measured differential photometry enabled us to determine that the companion is an early M dwarf with a mass estimate of 0.33-0.45 M?. The companion has a projected separation of 10 AU, which is one of the smallest projected separations of an exoplanet host binary system. Based on the limited astrometry collected, we are able to constrain the orbit of the stellar companion to a semi-major axis of 35{60 AU, an eccentricity ? 0.5 and an inclination of 75{85?. The stellar companion has likely strongly in uenced the orbit of the exoplanet and quite possibly explains its high eccentricity.Comment: Accepted to the Astronomical Journal, 6 Pages, 5 Figure

Facilitizing the Palomar AO laser guide star system

We describe the work that has gone into taking the sodium Laser Guide Star (LGS) program on the Palomar AO system from a successful experiment to a facility instrument. In particular, we describe the operation of the system, the BTO (beam transfer optics) system which controls the path of the laser in the dome, the aircraft safety systems and the optical systems which allow us to take advantage of the unique properties of the macro/micro pulse laser. In addition we present on sky performance results that demonstrate K-band Strehl ratios of up to 48

Status of the PALM-3000 high-order adaptive optics system

The PALM-3000 upgrade to the Palomar Adaptive Optics system on the 5.1 meter Hale telescope will deliver extreme adaptive optics correction in near-infrared wavelengths and diffraction-limited images in visible wavelengths. PALM-3000 will use a 3388-actuator tweeter and a 241-actuator woofer deformable mirror, a Shack-Hartmann wavefront sensor with selectable pupil sampling, and an innovative wavefront control computer based on a cluster of 17 graphics processing units to correct wavefront aberrations at scales as fine as 8.1 cm at the telescope pupil using natural guide stars. The system is currently undergoing integration and testing, with deployment at Palomar Observatory planned in early 2011. We present the detailed design of key aspects of the adaptive optics system, and the current status of the deformable mirror characterization, wavefront sensor performance, and testbed activities