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PALM-3000 (P3K), the second generation adaptive optics (AO) instrument for the 5.1 meter Hale telescope at Palomar Observatory, was released as a facility class instrument in October 2011 and has since been used on-sky for over 600 nights as a workhorse science instrument and testbed for coronagraph and detector development. In late 2019 P3K underwent a significant upgrade to its wavefront sensor (WFS) arm and real-time control (RTC) system to reinforce its position as a state-of-the-art AO facility and extend its faint-end capability for high-resolution imaging and precision radial velocity follow-up of Kepler and TESS targets. The main features of this upgrade include an EM-CCD WFS camera capable of 3.5 kHz framerates, and an advanced Digital signal Processor (DSP) based RTC system to replace the aging GPU based system. Similar to the pre-upgrade system, the Shack-Hartmann wavefront sensor supports multiple pupil sampling modes using a motorized lenslet stage. The default sampling mode with 64x64 subapertures has been re-commissioned on-sky in late 2019, with a successful return to science observations in November 2019. In 64x mode the upgraded system is already achieving K-band Strehl ratios up to 85% on sky and can lock on natural guide stars as faint as mV=16. A 16x16 subaperture mode is scheduled for on-sky commissioning in Fall 2020 and will extend the system's faint limit even further. Here we present the design and on-sky re-commissioning results of the upgraded system, dubbed P3K-II., Comment: 13 pages, 10 figures. To appear in Proceedings of SPIE ATI 2020

We present DARKNESS (the DARK-speckle Near-infrared Energy-resolving Superconducting Spectrophotometer), the first of several planned integral field spectrographs to use optical/near-infrared Microwave Kinetic Inductance Detectors (MKIDs) for high-contrast imaging. The photon counting and simultaneous low-resolution spectroscopy provided by MKIDs will enable real-time speckle control techniques and post-processing speckle suppression at framerates capable of resolving the atmospheric speckles that currently limit high-contrast imaging from the ground. DARKNESS is now operational behind the PALM-3000 extreme adaptive optics system and the Stellar Double Coronagraph at Palomar Observatory. Here we describe the motivation, design, and characterization of the instrument, early on-sky results, and future prospects., Comment: 17 pages, 17 figures. PASP Published

Residual speckles due to aberrations arising from optical errors after the split between the wavefront sensor and the science camera path are the most significant barriers to imaging extrasolar planets. While speckles can be suppressed using the science camera in conjunction with the deformable mirror, this requires knowledge of the phase of the electric field in the focal plane. We describe a method which combines a coronagraph with a simple phase-shifting interferometer to measure and correct speckles in the full focal plane. We demonstrate its initial use on the Stellar Double Coronagraph at the Palomar Observatory. We also describe how the same hardware can be used to distinguish speckles from true companions by measuring the coherence of the optical field in the focal plane. We present results observing the brown dwarf HD 49197b with this technique, demonstrating the ability to detect the presence of a companion even when it is buried in the speckle noise, without the use of any standard "calibration" techniques. We believe this is the first detection of a substellar companion using the coherence properties of light., Comment: 32 pages, 11 figures. Accepted for publication in MNRAS

We present a new instrument, the "Stellar Double Coronagraph" (SDC), a flexible coronagraphic platform. Designed for Palomar Observatory's 200" Hale telescope, its two focal and pupil planes allow for a number of different observing configurations, including multiple vortex coronagraphs in series for improved contrast at small angles. We describe the motivation, design, observing modes, wavefront control approaches, data reduction pipeline, and early science results. We also discuss future directions for the instrument., Comment: 25 pages, 12 figures. Correspondence welcome. The published work is open access and differs trivially from the version posted here. The published version may be found at http://iopscience.iop.org/article/10.1088/1538-3873/128/965/075003/meta

We present a close companion search around sixteen known early-L dwarfs using aperture masking interferometry with Palomar laser guide star adaptive optics. 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 Delta_K ~ 2.3 for separations between 1.2 - 4 lambda/D, and Delta_K ~ 1.4 at (2/3)lambda/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 laser guide star adaptive optics at Palomar. Several new techniques for the analysis of aperture masking data in the low signal to noise regime are explored., Comment: 13 pages, 7 figures, 3 tables, accepted by ApJ

PALM-3000 (P3K), the second-generation adaptive optics (AO) instrument for the 5.1 meter Hale telescope atPalomar Observatory, was released as a facility class instrument in October 2011 and has since been used on-skyfor over 600 nights as a workhorse science instrument and testbed for coronagraph and detector development.In late 2019 P3K underwent a significant upgrade to its wavefront sensor (WFS) arm and real-time control(RTC) system to reinforce its position as a state-of-the-art AO facility and extend its faint-end capability forhigh-resolution imaging and precision radial velocity follow-up of Kepler and TESS targets. The main featuresof this upgrade include an EM-CCD WFS camera capable of 3.5 kHz framerates, and an advanced Digital SignalProcessor (DSP) based RTC system to replace the aging GPU based system. Similar to the pre-upgrade system,the Shack-Hartmann wavefront sensor supports multiple pupil sampling modes using a motorized lenslet stage.The default sampling mode with 64×64 subapertures has been re-commissioned on-sky in late 2019, witha successful return to science observations in November 2019. In 64×mode the upgraded system is alreadyachieving K-band Strehl ratios up to 85% on-sky and can lock on natural guide stars as faint as mV=16. A16×16 subaperture mode is scheduled for on-sky commissioning in Fall 2020 and will extend the system’s faintlimit even further. Here we present the design and on-sky re-commissioning results of the upgraded system,dubbed P3K-II.

UNKNOWN

The Thirty Meter Telescope primary mirror is composed of 492 segments that are controlled to high precision in the presence of wind and vibration disturbances, despite the interaction with structural dynamics. The higher bandwidth and larger number of segments compared with the Keck telescopes requires greater attention to modeling to ensure success. We focus here on the development and validation of a suite of quasi-static and dynamic modeling tools required to support the design process, including robustness verification, performance estimation, and requirements flowdown. Models are used to predict the dynamic response due to wind and vibration disturbances, estimate achievable bandwidth in the presence of control-structure-interaction (CSI) and uncertainty in the interaction matrix, and simulate and analyze control algorithms and strategies, e.g. for control of focus-mode, and sensor calibration. Representative results illustrate TMT performance scaling with parameters, but the emphasis is on the modeling framework itself.

The Gemini Planet Imager is an extreme adaptive optics system that will employ an apodized-pupil coronagraph to make direct detections of faint companions of nearby stars to a contrast level of the 10(exp -7) within a few lambda/D of the parent star. Such high contrasts from the ground require exquisite wavefront sensing and control both for the AO system as well as for the coronagraph. Un-sensed non-common path phase and amplitude errors after the wavefront sensor dichroic but before the coronagraph would lead to speckles which would ultimately limit the contrast. The calibration wavefront system for GPI will measure the complex wavefront at the system pupil before the apodizer and provide slow phase corrections to the AO system to mitigate errors that would cause a loss in contrast. The calibration wavefront sensor instrument for GPI has been built. We will describe the instrument and its performance.