scholarly journals Binary star astrometry with milli and sub-milli arcsecond precision

2014 ◽  
pp. 1-21
Author(s):  
S. Jankov ◽  
Z. Cvetkovic ◽  
R. Pavlovic
Keyword(s):  
Adaptive Optics ◽  
Binary Stars ◽  
Binary Star ◽  
Speckle Interferometry ◽  
Spectroscopic Binaries ◽  
Fundamental Parameters ◽  
Long Baseline ◽  
Short Period ◽  
Observational Techniques ◽  
Near Future

The past several decades have seen accelerating progress in improving binary stars fundamental parameters determinations, as new observational techniques have produced visual orbits of many spectroscopic binaries with a milli arcsecond precision. Modern astrometry is rapidly approaching the goal of sub-milli arcsecond precision, and although presently this precision has been achieved only for a limited number of binary stars, in the near future this will become a standard for very large number of objects. In this paper we review the representative results of techniques which have already allowed the sub-milli arcsecond precision like the optical long baseline interferometry, as well as the precursor techniques such as speckle interferometry, adaptive optics and aperture masking. These techniques provide a step forward from milli to sub-milli arcsecond precision, allowing even short period binaries to be resolved, and often resulting in orbits allowing precisions in stellar dynamical masses better than 1%. We point out that such unprecedented precisions should allow for a significant improvement of our comprehension of stellar physics and other related astrophysical topics.

scholarly journals Sub-Milliarcsecond Optical Astrometry and Binary Stars

1995 ◽  
Vol 166 ◽  
pp. 193-202
Author(s):  
J.T. Armstrong
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Optical Interferometry ◽  
Light Curves ◽  
Spectroscopic Binaries ◽  
Indirect Methods ◽  
Fundamental Parameters ◽  
Long Baseline

Long-baseline optical interferometry has made it possible to measure the visual orbits of binary stars with major axes as small as 5 mas and errors of ≲ 100 μas. Interferometers now nearing completion will extend these values to ≳ 500 μas and σa ∼ 10 μas. Observations of double-lined spectroscopic binaries with current interferometers have already yielded some mass estimates with precisions rivaling those from fitting the light curves of eclipsing double-lined systems. Luminosity estimates based on combined visual interferometric observations and velocity curves are often more precise than those from more indirect methods based on estimates of Teff. New interferometers now coming into operation will make it possible to measure fundamental parameters in dozens to hundreds of binary systems.

scholarly journals Interferometric measurements of binaries

1997 ◽  
Vol 189 ◽  
pp. 109-114
Author(s):  
H.A. McAlister
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Center Of Mass ◽  
Angular Separation ◽  
Eclipsing Binaries ◽  
Spectroscopic Binaries ◽  
Past Performance ◽  
Short Period ◽  
Stellar Masses

This paper is a brief overview of the past performance and future promise of interferometry as applied to the study of binary stars. For the sake of brevity, the important results from infrared techniques in recent years are regretfully omitted here. It is probably unnecessary to remind the reader that the analysis of binary star orbital motions is the only direct means for the determination of stellar masses. Historically, stellar masses have resulted primarily from orbits that are sufficiently wide in angular separation to permit the astrometric determination of the motions of the individual components about the center of mass as well as the parallax of the system or from short-period spectroscopic/eclipsing binaries. The advent of long baseline optical interferometers holds the promise of a wealth of new stellar mass data through the direct resolution of spectroscopic binaries.

scholarly journals The Potential of Long–Baseline Optical Interferometry of Binary Stars

1992 ◽  
Vol 135 ◽  
pp. 527-535 ◽  
Author(s):  
H.A. McAlister
Keyword(s):  
Binary Stars ◽  
Speckle Interferometry ◽  
Stellar Mass ◽  
Optical Interferometry ◽  
Spectroscopic Binaries ◽  
Direct Imaging ◽  
Multiple Star ◽  
Long Baseline ◽  
Stellar Interferometer

AbstractInterferometric arrays possessing sub-milliarcsecond resolution are either about to be fully scientifically productive, as in the case of the Sydney University Stellar Interferometer, or are under various stages of planning and development. The 1990’s will thus witness a hundred–fold gain in resolution over speckle interferometry at the largest telescopes and 5,000 times the resolution of classical direct imaging. Where speckle interferometry can now resolve binary stars with periods of 1 to 2 years, interferometric arrays with baselines of hundreds of meters will resolve binaries with periods of a few hours. Arrays will resolve the majority of the known spectroscopic binaries, providing a substantial increase in the quantity and quality of stellar mass determinations. Surveys for new binaries among the field stars and other restricted samples will be accomplished with unprecedented completeness. The remarkable enhancement in resolution we are about to witness from facilities like SUSI and our own proposed CHARA Array will quite literally revolutionize the field of double and multiple star research.

scholarly journals The Calibration of Interferometrically Determined Properties of Binary Stars

1985 ◽  
Vol 111 ◽  
pp. 97-119
Author(s):  
Harold A. McAlister
Keyword(s):  
Binary Stars ◽  
Angular Resolution ◽  
Binary Star ◽  
Angular Separation ◽  
Speckle Interferometry ◽  
Close Binaries ◽  
High Angular Resolution ◽  
Fundamental Field ◽  
Enhanced Resolution ◽  
Stellar Masses

With the advent of speckle interferometry, high angular resolution has begun to play a routine role in the study of binary stars. Speckle and other interferometric techniques not only bring enhanced resolution to this classic and fundamental field but provide an equally important gain in observational accuracy. These methods also offer the potential for performing accurate differential photometry for binary stars of very small angular separation. This paper reviews the achievements of modern interferometric techniques in measuring stellar masses and luminosities and discusses the special calibration problems encountered in binary star interferometry. The future possibilities for very high angular resolution studies of close binaries are also described.

scholarly journals Double and Multiple Star Speckle Observations at the 6-m Telescope

1992 ◽  
Vol 135 ◽  
pp. 469-476
Author(s):  
I.I. Balega ◽  
Y.Y. Balega ◽  
V.A. Vasyuk ◽  
J.J. McManus
Keyword(s):  
Binary Stars ◽  
Photon Counting ◽  
Speckle Interferometry ◽  
Spectroscopic Binaries ◽  
Multiple Star ◽  
Stellar Spectra ◽  
Ss 433 ◽  
Composite Spectra ◽  
Wide Range ◽  
Single Aperture

During the last 15 years more than 9,000 speckle interferometric measurements of binary stars have been collected using large optical telescopes (McAlister & Hartkopf 1988). Among them a significant contribution to the world speckle data has been made by the 6-m telscope near Zelenchuk. Up to now this instrument provides the maximal spatial resolution for single–aperture telescopes. First speckle images of the binary Capella were recorded at the telescope in 1977 (Balega & Tikhonov 1977), but we spent 5 more years to create special television techniques for photon counting and digital means for image processing before we started the regular interferometric program of binary observations in the wide range of stellar magnitudes. At first, the measurements were conducted in cooperation with French astronomers from the Centre d’Etudes et de Recherches Geodynamiques et Astronomiques using the optical camera and the television detector developed by Blazit et al. (1977). Since 1983 our equipment has been in use. The program of observations was oriented upon the traditional problems of multiple star speckle interferometry:1.Determination of stellar distances and masses for different types of binaries whose orbital elements can be derived. This includes already known fast visual and astrometric pairs with undetermined orbits, spectroscopic binaries that can be resolved directly, and newly discovered interferometric pairs which show fast orbital motion. The main attention was devoted to the late–type dwarfs in the vicinity of the Sun.2.Search for the secondary components whose existence could explain anomalies of stellar spectra or photometry (stars with composite spectra, occultation binaries, etc.)3.Study of unusual binaries (symbiotic stars, binaries with relativistic components, such as SS 433, etc.)

scholarly journals Statistical Properties of Solar-Type Close Binaries

2004 ◽  
Vol 191 ◽  
pp. 20-27
Author(s):  
J.-L. Halbwachs ◽  
M. Mayor ◽  
S. Udry ◽  
F. Arenou
Keyword(s):  
Binary Stars ◽  
Equal Mass ◽  
Open Clusters ◽  
Statistical Properties ◽  
Spectroscopic Binaries ◽  
Close Binary ◽  
Close Binaries ◽  
Multiple Systems ◽  
Short Period ◽  
Mass Ratios

AbstractTwo Coravel radial velocity surveys dedicated to F7-K field dwarfs and to open clusters are merged in order to investigate the statistical properties of binaries with periods up to 10 years. Thanks to the accurate trigonometric parallaxes provided by Hipparcos, an unbiased sample of spectroscopic binaries (SB) is selected. After correction for the uncertainties of the measurements, the following results are obtained: 1. The distribution of mass ratios exhibits a peak for equal-mass binaries (twins), which is higher for short-period binaries than for long-period binaries. 2. Apart from the twins, the distribution of mass ratios exhibits a broad peak from 0.2 to 0.6. 3. The orbital eccentricities of twins are slightly smaller than those of other binaries. 4. An excess of SB is observed with periods shorter than about 50 days in comparison with the Duquennoy and Mayor log-normal distribution of periods. These features suggest that close binary stars are generated by two different processes. A possible difference could come from the accretion onto the binary, for instance from a common envelope or from a circumbinary disk. Alternatively, twins could come from dynamic evolution of multiple systems. It is not clear whether the formation models are already sufficiently elaborated to reproduce our statistics.

scholarly journals Overview of Multiple–Aperture Interferometry Binary Star Results from the Northern Hemisphere

2006 ◽  
Vol 2 (S240) ◽  
pp. 35-44
Author(s):  
Harold A. McAlister
Keyword(s):  
Northern Hemisphere ◽  
Binary Stars ◽  
Binary Star ◽  
Basic Principles ◽  
Long Baseline ◽  
Interferometric Study ◽  
The Individual ◽  
The Masses ◽  
Complete Specification

AbstractLong-baseline optical interferometry (LBI) can nearly close the gap in selection space between astrometric and spectroscopic detection of binary star systems, bringing the complementary powers of astrometry and spectroscopy to bear on a complete dynamical understanding of such systems, particularly including the determination of the masses of the individual stellar components. In the case of double-lined spectroscopic systems, their resolution by long-baseline interferometry also yields the orbital parallax and hence the luminosities of the individual stars. In some of these cases, the angular diameters of one or more components are accessible, and so a complete specification of a star in terms of its mass, radius and luminosity is made.The northern hemisphere is now equipped with several interferometers of unprecedented capability in terms of their baseline sizes, numbers of telescopes and telescope apertures. These instruments, most notably the Palomar Testbed Interferometer at Mt. Palomar Observatory, have produced very significant results of a number of interesting systems fulfilling interferometry's promise to produce fundamental astrophysical data at levels of accuracy that challenge or confirm astrophysical theory.This paper presents basic principles of long-baseline interferometric study of binary stars and summarizes results from northern interferometers with specific examples of their broad impact on binary star astronomy.

scholarly journals Twenty Years of Speckle Interferometry

1992 ◽  
Vol 135 ◽  
pp. 459-468
Author(s):  
William I. Hartkopf
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Michelson Interferometer ◽  
Speckle Interferometry ◽  
New Technique ◽  
Orbital Elements ◽  
Interferometric Technique ◽  
Infra Red ◽  
Michelson Interferometry ◽  
Using Data

The purpose of my talk is to briefly review the results of two decades of astrometric research using the technique of speckle interferometry. Although speckle, invented by Labeyrie in 1970 (Gezari et al. 1972), is the most well–known and widely–used interferometric technique in the visible and near infra-red, it neither the only technique in use, nor was it the first. Karl Schwarzschild made the first interferometric measurements of binary stars in 1895, using the then–new technique of Michelson interferometry and following a suggestion by Michelson himself that his technique was amenable to binary star astrometry. From 1919 to 1921, Anderson (1920) and Merrill (1922) made a series of measurements of Capella and other bright stars, using a Michelson interferometer of 20-foot baseline, mounted on the Mount Wilson 100-inch. These early measurements have definitely stood the test of time. Figure 1 shows a recently calculated orbit of Capella (Bagnuolo & Hartkopf 1989), using data spanning some 250 full revolutions. Anderson and Merrill’s measurements agree beautifully with observations made 7 decades later. As a result, Capella has probably the most accurately known orbit of any visual binary. Orbital elements calculated in 1981 (McAlister 1981) and again 10 years later differ in period by about 14 seconds, or less than 2 parts per million!

scholarly journals Interferometry and Lunar Occultations: Status and Prospects of Ground-Based Milliarcsecond Resolution Observations

2004 ◽  
Vol 191 ◽  
pp. 247-250 ◽  
Author(s):  
A. Richichi
Keyword(s):  
Binary Stars ◽  
Binary Star ◽  
Observational Methods ◽  
Research Programs ◽  
Long Baseline ◽  
The Status ◽  
Near Term

AbstractLunar occultations and long-baseline interferometry are two direct observational methods capable of delivering milliarcsecond resolution of binary stars. We will review the status of these two techniques, particularly with reference to their respective advantages, limitations, and accessibility for binary star research programs. We will also illustrate the near-term prospects, in connection with the availability of large modern interferometric facilities such as the VLTI.

scholarly journals Eclipsing Spectroscopic Binaries in the SMC

2005 ◽  
Vol 13 ◽  
pp. 455-455 ◽  
Author(s):  
Ron W. Hilditch ◽  
Tim J. Harries ◽  
Ian D. Howarth
Keyword(s):  
Binary Stars ◽  
Binary Systems ◽  
Binary Star ◽  
Theoretical Models ◽  
Eclipsing Binaries ◽  
Spectroscopic Binaries ◽  
Close Binary ◽  
Exchange Processes ◽  
The Mean ◽  
Close Binary Star

The OGLE survey of the SMC has discovered ~1500 eclipsing binaries thereby providing an excellent platform to study the evolution of close binary systems through case A and case B mass-exchange processes. The complementary spectroscopic radial-velocity studies of these binaries are now in progress and are revealing many interesting systems which challenge current theoretical models of close binary star evolution. These studies also provide excellent direct determinations of distances to these binary stars leading to an improved understanding of the mean distance to the SMC and its 3-D structure. Comparisons between these binary-star distances and other methods of determining the mean distance to the SMC will also be made.

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