Spatial interferometry in optical astronomy

A bibliographic guide is presented to publications of spatial interferometry techniques applied to optical astronomy. Listings appear in alphabetical order, by first author, as well as in specific subject categories listed in chronological order, including imaging theory and speckle interferometry, experimental techniques, and observational results of astronomical studies of stars, the Sun, and the solar system

Speckle noise and dynamic range in coronagraphic images

This paper is concerned with the theoretical properties of high contrast coronagraphic images in the context of exoplanet searches. We derive and analyze the statistical properties of the residual starlight in coronagraphic images, and describe the effect of a coronagraph on the speckle and photon noise. Current observations with coronagraphic instruments have shown that the main limitations to high contrast imaging are due to residual quasi-static speckles. We tackle this problem in this paper, and propose a generalization of our statistical model to include the description of static, quasi-static and fast residual atmospheric speckles. The results provide insight into the effects on the dynamic range of wavefront control, coronagraphy, active speckle reduction, and differential speckle calibration. The study is focused on ground-based imaging with extreme adaptive optics, but the approach is general enough to be applicable to space, with different parameters.Comment: 31 pages, 18 figure

Introduction to stellar coronagraphy

This paper gives a simple and original presentation of various coronagraphs inherited from the Lyot coronagraph. We first present the Lyot and Roddier phase mask coronagraphs and study their properties as a function of the focal mask size. We show that the Roddier phase mask can be used to produce an apodization for the star. Optimal coronagraphy can be obtained from two main approaches, using prolate spheroidal pupil apodization and a finite-size focal mask, or using a clear aperture and an infinite mask of variable transmission

Astronomy with adaptive optics: experiences from the University of Hawaii AO program

The University of Hawaii adaptive optics (AO) group has been actively carrying out astronomical AO observations for the last four years. The UHAO group and our collaborators have utilized the curvature AO system to obtain diffraction-limited images of asteroids, planets, moons, protoplanetary disks, young stars, young star clusters, planetary nebulae, black holes, galaxies, and quasars. The current scientific capabilities of the new 36-actuator Hokupaa AO curvature system will be briefly reviewed. Four key astronomical situations that are excellent for AO observations will be discussed. Examples of scientific observational techniques and limitations will be highlighted with actual AO astronomical results. INTRODUCTION The University of Hawaii AO program has been actively doing astronomical observations with adaptive optics since early 1994. The instrument has evolved from an experimental Coude prototype curvature system, to a highly-productive 13 actuator cassegrain curvature instrume..

First Light for Hokupa'a

The University of Hawaii adaptive optics program has scaled it's previously successful 13 elements AO system to 36 actuators and named it "Hokupa'a", meaning "immovable star" in Hawaiian. First light for Hokupa'a, in early Nov. of 1997, was on the Canada France Hawaii Telescope (CFHT) on Mauna Kea, an f/35, 3.35 meter telescope. Performance at the telescope has now been measured and compares favorably with that predicted theoretically. The extension to 36 elements has now allowed the system to give diffraction limited performance down to I band (0.85 microns) on stars as faint as 12.5 magnitude in median 0.7 arcsecond seeing on Mauna Kea. Like our previous system, extensive computer simulations were carried out to achieve the best possible match between the curvature WFS and the deformable curvature mirror. Keywords: Adaptive optics, AO optical system design, curvature wavefront sensing, curvature deformable mirrors, AO telescope performance. Introduction The University of Hawaii adap..

Adaptive Optics J Band Imaging Polarimetry Observations of the Circumbinary Disk around UY Aurigae

. We have obtained J band (1.2 µm) polarimetry observations of the circumbinary disk around UY Aurigae with the University of Hawaii 36 element adaptive optics instrument, Hokupa'a, at the 3.6 m CFHT. The deep (120 min), high resolution (0.15") polarization map reveals a centrosymmetric polarization signature from the light scattered off the circumbinary dust disk which is ~10 6 times fainter than the stars in the binary system. PLUCY deconvolution is shown to successfully remove the wings of the unpolarized stellar PSF which contaminates the polarization signal of the disk. The first measurements of the polarization (~1.5%) of the two individual stellar components of UY Aur are reported as well. 1.0 Introduction Near infrared observations of the circumstellar disks around T-tauri stars are difficult due to the close proximity of these disks to their bright central star(s). Consequently, only a handful of circumstellar disks around T-Tauri stars have been resolved in their scattere..

Proc. SPIE 3353, March 23-26 1998, Kona, Hawaii

The University of Hawaii adaptive optics (AO) group has been actively carrying out astronomical AO observations for the last four years. The UHAO group and our collaborators have utilized the curvature AO system to obtain diffraction-limited images of asteroids, planets, moons, protoplanetary disks, young stars, young star clusters, planetary nebulae, black holes, galaxies, and quasars. The current scientific capabilities of the new 36-actuator Hokupaa AO curvature system will be briefly reviewed. Four key astronomical situations that are excellent for AO observations will be discussed. Examples of scientific observational techniques will be highlighted with actual AO astronomical results. Keywords: adaptive optics, AO point spread function, polarization, AO observing techniques, binary stars INTRODUCTION The University of Hawaii AO program has been actively doing astronomical observations with adaptive optics since early 1994. The instrument has evolved from an experimental Coude pr..

NSPIRING ALUMNI STORIES: TESTIMONIALS OF BLUE DOCTORATE HOLDERS

International audienceThis booklet of testimonies retraces the career paths of doctors in marine, maritime and coastal sciences. It focuses on experiences outside the academia. It is a collective output of a European Erasmus+ project involving the universities of Brest, Gdansk, Cadiz, Split, Kiel and Malta working within SEA-EU DOC project. This project aims to broaden employment opportunities for doctors by preparing doctorate students for a wide range of career options matching the reality of the labour market. The sectors constituting the blue economy are developing very dynamically. It is, therefore, important to analyse development opportunities for PhD holders based on examples of successful careers outside the academia. The method used to examine these “success stories” was an interview. The interview analysis allowed to draw conclusions on the factors that may influence the success of doctorate holders in developing careers outside the academic sector. This, in turn, allowed to identify the key elements that should be included in doctoral training programmes and ensured that doctoral students obtain the qualifications and skills expected by employers of the current and future labour market. These interviews are used as informative material to present the diversity of employment opportunities for doctorate holders. They are disseminated through open online access on the SEA-EU platform and the partners’ websites. The main objective of the interviews is to get a picture of PhD graduates’ career path from the moment they decided to undertake PhD studies up to the point when they developed their careers. During the SEA-EU DOC project, a total of 60 doctorate holders from 6 countries were interviewed (51% of them were male and 49% female). Participants represented diverse scientific fields. The Earth sciences (41%) was the most represented field, while engineering (16%) was the least. The majority of doctorate holders worked at their current job for over three years. Most of them (77%) worked in their home country. Among the interviewed PhD holders three most popular blue economy sectors were environmental monitoring and protection (32%), offshore wind power (16%) and science communication (12%). The two least popular sectors were marine biotechnology and mineral resources (each 2%). Additionally, 22% of doctorate holders worked simultaneously in at least two sectors. This collection of testimonials presents the diversity of career paths of doctorate holders and focuses on valuable skills acquired during the doctorate that can be transferred to any work context. It is also intended to be a collection of messages sent by these doctorate holders to current doctoral students and to companies likely to hire them

James Beattie, Jean-Jacques Rousseau and the character of Common Sense philosophy

Professor of Moral Philosophy at Marischal College, Aberdeen, James Beattie (1735–1803) was one of the most prominent literary figures of late eighteenth-century Britain. His major works, An Essay on the Nature and Immutability of Truth (1770) and the two-canto poem The Minstrel (1771–1774), were two of the best-sellers of the Scottish Enlightenment and were key to Beattie’s role in the emergence of both the ‘Scottish School’ of Common Sense Philosophy and British Romanticism. Intellectual history scholarship on the Scottish Enlightenment has tended to discuss Beattie in terms of his relationship to his fellow Aberdonian Thomas Read. While clearly important, his link with Reid does not exhaust our potential interest in Beattie. This article explores his extensive engagement with the thought of Jean-Jacques Rousseau (1712–1778). In the process, it is argued that the Genevan’s works–especially the Confession of the Savoyard Vicar in Emile (1762)–played an important though little noticed role in both Beattie’s rhetoric and anti-scepticism in both the Essay and Minstrel. Moreover, Beattie’s initially praising stance on Rousseau as a potential friend to true religion indicates the complexity of the reception of the Genevan’s works in late eighteenth-century Britain