A5102997643- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Planetary Science and Exploration
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Spacecraft Design and Technology
- Optical measurement and interference techniques
- Advanced Measurement and Metrology Techniques
- Optical Systems and Laser Technology
- Relativity and Gravitational Theory
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Cold Atom Physics and Bose-Einstein Condensates
- CCD and CMOS Imaging Sensors
- Optical Polarization and Ellipsometry
- Space Science and Extraterrestrial Life
- Scientific Research and Discoveries
- Pulsars and Gravitational Waves Research
State Key Joint Laboratory of Environment Simulation and Pollution Control
2019
Jet Propulsion Laboratory
2007-2016
Campbell Collaboration
2011
California Institute of Technology
1991-2009
Nicolaus Copernicus Astronomical Center
2006
Polish Academy of Sciences
2006
Smithsonian Astrophysical Observatory
1985-1991
The Palomar Testbed Interferometer (PTI) is a long-baseline infrared interferometer located at Observatory, California. It was built as testbed for interferometric techniques applicable to the Keck Interferometer. First fringes were obtained in 1995 July. PTI implements dual-star architecture, tracking two stars simultaneously phase referencing and narrow-angle astrometry. three fixed 40 cm apertures can be combined pairwise provide baselines 110 m. actively tracks white-light fringe using...
The need for high dynamic range imaging is crucial in many astronomical fields, such as extra-solar planet direct detection, extra-galactic science and circumstellar imaging. Using a quality coronograph, ranges of up to $10^{5}$ have been achieved. However the ultimate limitations coronographs do not come from their optical performances, but scattering due imperfections surfaces collecting system. We propose use deformable mirror correct these decrease level local regions called ``dark...
We obtained spectra in the wavelength range λ = 995–1769 nm of all four known planets orbiting star HR 8799. Using suite instrumentation as Project 1640 on Palomar 5 m Hale Telescope, we acquired data at two epochs. This allowed for multiple imaging detections companions and extractions low-resolution (R ∼ 35) spectra. Data reduction employed different methods speckle suppression spectrum extraction, both yielding results that agree. The do not directly correspond to those any objects,...
We present an analysis of the orbital motion four sub-stellar objects orbiting HR8799. Our study relies on published astrometric history this system augmented with epoch obtained Project 1640 coronagraph + Integral Field Spectrograph (IFS) installed at Palomar Hale telescope. first focus intricacies associated estimation using combination Extreme Adaptive Optics (PALM-3000), a and IFS. introduce two new algorithms. The one retrieves stellar focal plane position when star is occulted by...
We report the results of a sensitive K-band survey Herbig Ae/Be disk sizes using 85 m baseline Keck Interferometer. Targets were chosen to span maximum range stellar properties probe size dependence on luminosity and effective temperature. For most targets, measured near-infrared (ranging from 0.2 4 AU) support simple model possessing central optically thin (dust-free) cavity, ringed by hot dust emitting at expected sublimation temperatures (Ts ~1000-1500 K). Furthermore, we find tight...
The Palomar High-precision Astrometric Search for Exoplanet Systems monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Six binaries are presented that show evidence of substellar orbiting star. Of these six systems, likelihoods two detected perturbations represent real objects considered be "high confidence", while remaining four less...
The Keck Interferometer (KI) combined the two 10 m W. M. Observatory telescopes on Mauna Kea, Hawaii, as a long-baseline near- and mid-infrared interferometer. Funded by NASA, it operated from 2001 until 2012. KI used adaptive optics to correct individual wavefronts, well active fringe tracking in all modes for path-length control, including implementation of cophasing provide long coherent integration times. implemented high sensitivity fringe-visibility measurements at H (1.6 μm), K (2.2 L...
The Caltech HIgh-speed Multi-colour camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of Hale 200-inch telescope. Simultaneous optical imaging in two bands enabled by dichroic beam splitter centred 567 nm, with Sloan u′ and g′ available on blue arm r′, i′ z_s red arm. Additional narrow-band filters will also become as required. An electron multiplying CCD (EMCCD) detector employed both channels, each capable simultaneously delivering sub-electron...
Analytical relations are derived for the amplitude of astrometric, photometric and radial velocity perturbations caused by a single rotating spot. The relative power star spot jitter is estimated compared with available data $\kappa^1$ Ceti HD 166435, as well numerical simulations Sun. A Sun-like inclined at $i=90\degr$ 10 pc predicted to have RMS 0.087 \uas in its astrometric position along equator, 0.38 m s$^{-1}$ velocities. If presence spots due stellar activity ultimate limiting factor...
The small satellite 'Galileo Galilei' (GG) will test the universality of free fall and hence weak equivalence principle which is founding pillar general relativity to 1 part in 1017. It use proof masses whose atoms differ substantially from one another their mass energy content, so as maximize chance violation. GG improve by four orders magnitude current best 'Eöt-Wash' tests based on slowly rotating torsion balances, have been able reach thermal noise level. In GG, expected violation signal...
We present the first infrared interferometric observations of a young stellar object with spatial projected resolution better than 2 AU. The were obtained Palomar Testbed Interferometer (PTI). FU Orionis exhibits visibility V2=0.72 ± 0.07 for 103 5 m-projected baseline at λ=2.2 μm. On scale probed by PTI, data are consistent both binary system scenario (a maximum magnitude difference 2.7 0.5 mag and smallest separation 0.35 0.05 AU) standard luminous accretion disk model ( ~6 × 10−5 M☉...
We have measured power spectra of atmospheric phase fluctuations with the Mark III stellar interferometer on Mt. Wilson under a wide variety seeing conditions. On almost all nights, high-frequency portions temporal closely follow form predicted by standard Kolmogorov-Tatarski model. At lower frequencies, behavior is observed. few clearly exhibit low-frequency flattening characteristic turbulence an outer-scale length order 30 m. other examination individual yields no strong evidence outer...
The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 sub-arcsecond binary systems to determine precision orbits, study the geometries of triple and quadruple star systems, discover previously unknown faint astrometric companions as small giant planets.PHASES measurements made with Testbed Interferometer (PTI) from 2002 until PTI ceased normal operations in late 2008 are presented.Infrared differential photometry several PHASES targets were measured Keck...
Through the contributions of Galileo, Newton, and Einstein, we recall universality free fall (UFF), weak equivalence principle (WEP), strong (SEP), in order to stress that general relativity requires all test masses be equally accelerated a gravitational field; is, it UFF WEP hold. The possibility testing this crucial fact with null, highly sensitive experiments makes these most powerful tests theory. Following Schiff, derive redshift from special show that, as long clocks are affected by...
The Space Interferometry Mission PlanetQuest Light (or SIM-Lite) is a new concept for space borne astrometric instrument, to be located in solar Earth-trailing orbit. SIM-Lite utilizes technology developed over the past ten years SIM mission. instrument consists of two Michelson stellar interferometers and precision telescope. first interferometer chops between target star set Reference stars. second monitors attitude direction star. telescope other directions. will capable one...
An Inverse Synthetic Aperture LADAR (ISAL) system is capable of providing high resolution surface mapping near Earth objects which an ability that has gained significant interest for both exploration and hazard assessment. The use ISAL over these long distances often presents the need to operate optical in photon-starved conditions. This leads a necessity understand implications photon detector noise system. Here Carrier-to-Noise Ratio derived similar other imaging CNR definitions. value...
We have determined the visual orbit for spectroscopic binary ι Pegasi with interferometric visibility data obtained by Palomar Testbed Interferometer in 1997. Peg is a double-lined system whose minimum masses and spectral typing suggests possibility of eclipses. Our orbital component diameter determinations do not favor eclipse hypothesis: limb-to-limb separation two components 0.151±0.069 mas at conjunction. conclusion that does supported high-precision photometric observations. The...
NEAT, Nearby Exo-Earth Astrometric Telescope is a medium-small telescope ~ 1m in diameter that designed to make ultra precise < 1 uas (microarcsec) astrometric measurements of nearby stars 1hr observation. Four major error sources prevent normal space telescopes from obtaining accuracies close uas. Even with small telescope, photon noise usually not problem for the bright target stars. But general, reference are much fainter. Typically field view ~0.5 deg dia needed obtain enough The NEAT...
A new coronagraph that performs destructive interference between copies of the telescope pupil in which "slices" have been swapped is studied this paper. fourth‐order "pupil‐swapping coronagraph" particularly attractive for direct imaging extrasolar terrestrial planets: it achieves 100% throughput at 1.4 λ/d on a square (72.5% 1.77 circular pupil), compatible with central obstruction and spiders, delivers sharp images off‐axis sources. Direct detection planets appears theoretically feasible...
Context: Exoplanet science has made staggering progress in the last two decades, due to relentless exploration of new detection methods and refinement existing ones. Yet astrometry offers a unique untapped potential discovery habitable-zone low-mass planets around all solar-like stars solar neighborhood. To fulfill this goal, must be paired with high precision calibration detector. Aims: We present way calibrate detector for accuracy astrometry. An experimental testbed combining an...
We report on a near-infrared, long-baseline interferometric search for luminous companions to the star 51 Pegasi conducted with Palomar Testbed Interferometer. Our data is completely consistent single-star hypothesis. find no evidence suggest companion Pegasi, and we can exclude brighter than ΔK of 4.27 at 99% confidence level 4.2 day orbital period indicated by spectroscopic measurements. This corresponds an upper limit in MK 7.30, which turn implies main-sequence mass less 0.22 M☉.