- ID:
- ivo://CDS.VizieR/J/AJ/147/123
- Title:
- Speckle interferometry with SOAR in 2012-2013
- Short Name:
- J/AJ/147/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of speckle runs at the 4.1m Southern Astronomical Research telescope in 2012 and 2013. A total of 586 objects were observed. We give 699 measurements of 487 resolved binaries and upper detection limits for 112 unresolved stars. Eleven pairs (including one triple) were resolved for the first time. Orbital elements have been determined for the first time for 13 pairs; orbits of another 45 binaries are revised or updated.
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- ID:
- ivo://CDS.VizieR/J/AJ/162/156
- Title:
- Speckle interfero. nearby multiple stars. II
- Short Name:
- J/AJ/162/156
- Date:
- 14 Mar 2022 06:50:24
- Publisher:
- CDS
- Description:
- Long-term monitoring at the 6m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences made it possible to improve the orbits of 15 objects (HIP689, HIP3951, HIP10438, HIP43948, HIP69962, HIP95995, HIP102029, HIP102357, HIP104383, HIP105947, HIP106255, HIP108917, HIP111546, HIP113726, HIP114922) and construct an orbital solution for HIP65327 for the first time. Observations have been carried out since 2007; that is, the accumulated data correspond to an interval of 13yr. As a result, most of the orbits were classified as "accurate" using the qualitative criteria by Worley & Heintz. A comparison of the mass sums and masses of the components calculated by two independent methods was made for objects with orbital solutions. The Gaia EDR3 parallax was used to obtain the fundamental parameters, as well as the Hipparcos and Gaia DR2 parallaxes.
- ID:
- ivo://CDS.VizieR/J/AJ/106/1639
- Title:
- Speckle observations of binary stars
- Short Name:
- J/AJ/106/1639
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Speckle interferometric observations from the Canada-France-Hawaii 3.6m and Cerro Tololo 4 m telescopes are reported for 1123 stars selected from the Yale Bright Star Catalogue in a continuing effort to detect new binaries among the bright stars. Thirty-two previously unresolved binaries have been detected, including companions to Xi UMa and 15 S Mon. Measures of 107 previously resolved systems, many of which resulted from earlier speckle observations, are also presented. No evidence of duplicity within a specific (m,Delta(m),rho) window of detectability was found for 984 bright stars. These observations combined with two previously published surveys represent the inspection of 2088 stars, representing 23% of the members of the Bright Star Catalogue. Many of the systems discovered earlier have shown significant orbital motions, and we present preliminary orbital elements for six binaries. Eighteen other stars previously announced as bright binaries have not been confirmed following numerous attempts to do so, and we show that their apparently spurious nature is likely due to the domination of the speckle transfer function by moderate telescope aberrations under conditions of superb seeing encountered at the CFHT in 1985. After deletion of these spurious systems, this effort has resulted in the discovery of 75 new, bright binaries. We consider some aspects of the duplicity frequencies among the diverse spectral and luminosity classes represented in this sample. We anticipate that the completion of a speckle survey of the Bright Star Catalogue would lead to the discovery of at least 200 additional binary systems with angular separations mostly below 0.20". Many of these will have periods of the order of one decade and will be accessible to complementary radial velocity programs of enhanced precision.
- ID:
- ivo://CDS.VizieR/J/AJ/106/352
- Title:
- Speckle observations of binary stars VIII
- Short Name:
- J/AJ/106/352
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- One-thousand eighty-eight observations of 947 binary star systems, observed by means of speckle interferometry with the 4 m telescope on Cerro Tololo, are presented. These measurements, made during the period 1989-1991, comprise the second installment of results stemming from the expansion of our speckle program to the southern hemisphere.
- ID:
- ivo://CDS.VizieR/J/AJ/111/393
- Title:
- Speckle observations of binary stars. XII
- Short Name:
- J/AJ/111/393
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Five hundred sixty-five measurements of 99 binary star systems are presented, obtained during 1984-1986 by means of speckle interferometry at the 1.8 m Perkins telescope on Anderson Mesa, Arizona. These observations were collected as part of a systematic program in which frequent speckle observations of nearby binary systems were to be used to attempt the detection of unseen companions through the analysis of residual motions in wide, visual binaries. This is the first of several papers in which these observations are presented and discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/367/865
- Title:
- Speckle observations of binary systems
- Short Name:
- J/A+A/367/865
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From speckle observations made with the PISCO speckle camera at the Pic du Midi Observatory, we present high angular resolution astrometric data for 43 binary stars already observed by the Hipparcos satellite. This sample consists of mainly new Hipparcos eclipsing binaries with a visual companion closer than one arcsecond, chosen with the aim to study the dynamical implications of a third component on the observational parameters of the eclipsing system. In addition, we also included a selection of close visual binaries with few speckle data in order to analyse possible systematic departures between the speckle and the non-speckle orbits. The reduction method and the results are presented in detail. For the close visual binaries we confront our observations with the ephemerides based on the best known orbits. For the wide visual binaries the confrontation is made directly with the Hipparcos data. Our observations are consistent both with previous speckle data and with most of the Hipparcos measurements.
- ID:
- ivo://CDS.VizieR/J/AJ/141/45
- Title:
- Speckle observations of HIP stars
- Short Name:
- J/AJ/141/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of 497 speckle observations of Hipparcos stars and selected other targets are presented. Of these, 367 were resolved into components and 130 were unresolved. The data were obtained using the Differential Speckle Survey Instrument at the WIYN 3.5m Telescope. (The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories.) Since the first paper in this series, the instrument has been upgraded so that it now uses two electron-multiplying CCD cameras. The measurement precision obtained when comparing to ephemeris positions of binaries with very well known orbits is approximately 1-2mas in separation and better than 0fdg6 in position angle. Differential photometry is found to be in very good agreement with Hipparcos measures in cases where the comparison is most relevant. We derive preliminary orbits for two systems.
- ID:
- ivo://CDS.VizieR/J/AJ/142/19
- Title:
- Speckle observations of KOI
- Short Name:
- J/AJ/142/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from a speckle imaging survey of stars classified as candidate exoplanet host stars discovered by the Kepler mission. We use speckle imaging to search for faint companions or closely aligned background stars that could contribute flux to the Kepler light curves of their brighter neighbors. Background stars are expected to contribute significantly to the pool of false positive candidate transiting exoplanets discovered by the Kepler mission, especially in the case that the faint neighbors are eclipsing binary stars. Here, we describe our Kepler follow-up observing program, the speckle imaging camera used, our data reduction, and astrometric and photometric performance. Kepler stars range from R=8 to 16 and our observations attempt to provide background non-detection limits 5-6mag fainter and binary separations of ~0.05-2.0-arcsec. We present data describing the relative brightness, separation, and position angles for secondary sources, as well as relative plate limits for non-detection of faint nearby stars around each of 156 target stars. Faint neighbors were found near 10 of the stars.
- ID:
- ivo://CDS.VizieR/J/AJ/158/167
- Title:
- Speckle observations & orbits of multiple stars
- Short Name:
- J/AJ/158/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results of speckle-interferometric monitoring of visual hierarchical systems using the newly commissioned instrument NN-EXPLORE Exoplanet and Stellar Speckle Imager at the 3.5 m WIYN telescope. During one year, 390 measurements of 129 resolved subsystems were made, while some targets were unresolved. Using our astrometry and archival data, we computed 36 orbits (27 for the first time). Spectro-interferometric orbits of seven pairs are determined by combining positional measurements with radial velocities measured, mostly, with the Center for Astrophysics digital speedometers. For the hierarchical systems HIP 65026 (periods 49 and 1.23 yr) and HIP 85209 (periods 34 and 1.23 yr) we determined both the inner and the outer orbits using astrometry and radial velocities and measured the mutual orbit inclinations of 11.3{deg}+/-1.0{deg} and 12.0{deg}+/-3.0{deg}, respectively. Four bright stars are resolved for the first time; two of those are triple systems. Several visual subsystems announced in the literature are shown to be spurious. We note that subsystems in compact hierarchies with outer separations less than 100 au tend to have less eccentric orbits compared to wider hierarchies.
- ID:
- ivo://CDS.VizieR/J/AJ/162/75
- Title:
- Speckle observations TESS exoplanet host stars. II.
- Short Name:
- J/AJ/162/75
- Date:
- 18 Mar 2022 09:30:45
- Publisher:
- CDS
- Description:
- We present high-angular-resolution imaging observations of 517 host stars of TESS exoplanet candidates using the 'Alopeke and Zorro speckle cameras at Gemini North and South. The sample consists mainly of bright F, G, K stars at distances of less than 500pc. Our speckle observations span angular resolutions of ~20mas out to 1.2", yielding spatial resolutions of <10-500au for most stars, and our contrast limits can detect companion stars 5-9mag fainter than the primary at optical wavelengths. We detect 102 close stellar companions and determine the separation, magnitude difference, mass ratio, and estimated orbital period for each system. Our observations of exoplanet host star binaries reveal that they have wider separations than field binaries, with a mean orbital semimajor axis near 100 au. Other imaging studies have suggested this dearth of very closely separated binaries in systems which host exoplanets, but incompleteness at small separations makes it difficult to disentangle unobserved companions from a true lack of companions. With our improved angular resolution and sensitivity, we confirm that this lack of close exoplanet host binaries is indeed real. We also search for a correlation between planetary orbital radii versus binary star separation; but, given the very short orbital periods of the TESS planets, we do not find any clear trend. We do note that in exoplanet systems containing binary host stars, there is an observational bias against detecting Earth-size planet transits due to transit depth dilution caused by the companion star.
