Related papers: The Palomar Testbed Interferometer
Polarimetric interferometry is a method allowing the study of the distribution of polarized flux at diffraction-limited resolution. Its basic observable is the ratio $\mathcal{R}$ of the visibilities of the object in two orthogonal…
PHASECam is the fringe tracker for the Large Binocular Telescope Interferometer (LBTI). It is a near-infrared camera which is used to measure both tip/tilt and fringe phase variations between the two adaptive optics (AO) corrected apertures…
The Las Cumbres Observatory operates a fleet of robotically controlled telescopes currently two 2m, nine 1m, and ten 0.4m telescopes, distributed amongst six sites covering both hemispheres. Telescopes of an aperture class are equipped with…
We report high-resolution spectroscopic monitoring and long-baseline interferometric observations with the PTI of the 215-day binary system HD 174881 (K1 II-III), composed of two giant stars. The system is spatially resolved with the PTI,…
The Planet Formation Imager (PFI) initiative aims at developing the next generation large scale facility for imaging astronomical optical interferometry operating in the mid-infrared. Here we report on the progress of the Planet Formation…
The sensitivity and astrometry upgrade ASTRA of the Keck Interferometer is introduced. After a brief overview of the underlying interferometric principles, the technology and concepts of the upgrade are presented. The interferometric…
We describe SPIDER, a balloon-borne instrument to map the polarization of the millimeter-wave sky with degree angular resolution. Spider consists of six monochromatic refracting telescopes, each illuminating a focal plane of large-format…
At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment…
Experiments are in progress to prepare for intensity interferometry with arrays of air Cherenkov telescopes. At the Bonneville Seabase site, near Salt Lake City, a testbed observatory has been set up with two 3-m air Cherenkov telescopes on…
Interferometric measurements of optical path length differences of stars over large baselines can deliver extremely accurate astrometric data. The interferometer GRAVITY will simultaneously measure two objects in the field of view of the…
We give an introduction to interferometrical concepts and their applicability to Be stars. The first part of the paper concentrates on a short historic overview and basic principles of two-beam interferometric observations. In the second…
The South Pole Telescope (SPT) is a millimeter-wavelength telescope designed for high-precision measurements of the cosmic microwave background (CMB). The SPT measures both the temperature and polarization of the CMB with a large aperture,…
Intensity interferometry exploits a quantum optical effect in order to measure objects with extremely small angular scales. The first experiment to use this technique was the Narrabri intensity interferometer, which was successfully used in…
We present optical interferometric observations of two double-lined spectroscopic binaries, HD 6118 and HD 27483, taken with the Palomar Testbed Interferometer (PTI) in the K band. HD 6118 is one of the most eccentric spectroscopic binaries…
PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5 m optical/infrared telescope to be located at Dome C on the Antarctic plateau. The atmospheric conditions at Dome C deliver a high sensitivity, high…
The Pulsed All-sky Near-infrared Optical Search for ExtraTerrestrial Intelligence (PANOSETI) is an instrument program that aims to search for fast transient signals (nano-second to seconds) of artificial or astrophysical origin. The…
Bolometric Interferometry (BI) is one of the most promising techniques for precise measurements of the Cosmic Microwave Background polarization. In this paper, we present the results of DIBO (Demonstrateur d'Interferometrie Bolometrique), a…
Optical SETI (Search for Extraterrestrial Intelligence) instruments that can explore the very fast time domain, especially with large sky coverage, offer an opportunity for new discoveries that can complement multimessenger and time domain…
The ESO Very Large Telescope Interferometer (VLTI) is one of the leading interferometric facilities. It is equipped with several 8.2 and 1.8m telescopes, a large number of baselines up to 200m, and with several subsystems designed to enable…
A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work…