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Elliott P Horch - One of the best experts on this subject based on the ideXlab platform.
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observations of binary stars with the differential speckle Survey Instrument vi measures during 2014 at the discovery channel telescope
The Astronomical Journal, 2015Co-Authors: Elliott P Horch, Gerard T Van Belle, James W Davidson, Lindsay A Ciastko, Mark E Everett, K S BjorkmanAbstract:We present the results of 938 speckle measures of double stars and suspected double stars drawn mainly from the Hipparcos Catalog, as well as 208 observations where no companion was noted. One hundred fourteen pairs have been resolved for the first time. The data were obtained during four observing runs in 2014 using the Differential Speckle Survey Instrument at Lowell Observatory's Discovery Channel Telescope. The measurement precision obtained when comparing to ephemeris positions of binaries with very well-known orbits is generally less than 2 mas in separation and 05 in position angle. Differential photometry is found to have internal precision of approximately 0.1 mag and to be in very good agreement with Hipparcos measures in cases where the comparison is most relevant. We also estimate the detection limit in the cases where no companion was found. Visual orbital elements are derived for six systems.
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observations of binary stars with the differential speckle Survey Instrument vi measures during 2014 at the discovery channel telescope
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Elliott P Horch, Gerard T Van Belle, James W Davidson, Lindsay A Ciastko, Mark E Everett, K S BjorkmanAbstract:We present the results of 938 speckle measures of double stars and suspected double stars drawn mainly from the Hipparcos Catalogue, as well as 208 observations where no companion was noted. One hundred fourteen pairs have been resolved for the first time. The data were obtained during four observing runs in 2014 using the Differential Speckle Survey Instrument (DSSI) at Lowell Observatory's Discovery Channel Telescope. The measurement precision obtained when comparing to ephemeris positions of binaries with very well-known orbits is generally less than 2 mas in separation and 0.5 degrees in position angle. Differential photometry is found to have internal precision of approximately 0.1 magnitudes and to be in very good agreement with Hipparcos measures in cases where the comparison is most relevant. We also estimate the detection limit in the cases where no companion was found. Visual orbital elements are derived for 6 systems.
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observations of binary stars with the differential speckle Survey Instrument v toward an empirical metal poor mass luminosity relation
The Astronomical Journal, 2015Co-Authors: Elliott P Horch, William F Van Altena, Steve B Howell, David R Ciardi, Mark E Everett, Pierre Demarque, Johanna Teske, Todd J Henry, Jennifer G WintersAbstract:In an effort to better understand the details of the stellar structure and evolution of metal-poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and six stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. The mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory.
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observations of binary stars with the differential speckle Survey Instrument v toward an empirical metal poor mass luminosity relation
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Elliott P Horch, William F Van Altena, Steve B Howell, David R Ciardi, Mark E Everett, Pierre Demarque, Johanna Teske, Todd J Henry, Jennifer G WintersAbstract:In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and 6 stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. Mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory.
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observations of binary stars with the differential speckle Survey Instrument iii measures below the diffraction limit of the wiyn telescope
The Astronomical Journal, 2011Co-Authors: Elliott P Horch, William F Van Altena, William Sherry, Steve B Howell, David R CiardiAbstract:In this paper, we study the ability of CCD- and electron-multiplying-CCD-based speckle imaging to obtain reliable astrometry and photometry of binary stars below the diffraction limit of the WIYN 3.5 m Telescope. We present a total of 120 measures of binary stars, 75 of which are below the diffraction limit. The measures are divided into two groups that have different measurement accuracy and precision. The first group is composed of standard speckle observations, that is, a sequence of speckle images taken in a single filter, while the second group consists of paired observations where the two observations are taken on the same observing run and in different filters. The more recent paired observations were taken simultaneously with the Differential Speckle Survey Instrument, which is a two-channel speckle imaging system. In comparing our results to the ephemeris positions of binaries with known orbits, we find that paired observations provide the opportunity to identify cases of systematic error in separation below the diffraction limit and after removing these from consideration, we obtain a linear measurement uncertainty of 3-4 mas. However, if observations are unpaired or if two observations taken in the same filter are paired, it becomes harder to identify cases of systematic error, presumably because the largest source of this error is residual atmospheric dispersion, which is color dependent. When observations are unpaired, we find that it is unwise to report separations below approximately 20 mas, as these are most susceptible to this effect. Using the final results obtained, we are able to update two older orbits in the literature and present preliminary orbits for three systems that were discovered by Hipparcos.
Paul D. Blanc - One of the best experts on this subject based on the ideXlab platform.
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Designing a gamma hydroxybutyrate (GHB) structured telephone-administered Survey Instrument
Journal of Medical Toxicology, 2007Co-Authors: Jo E. Dyer, Ilene B. Anderson, Susan Y. Kim, Judith C. Barker, Paul D. BlancAbstract:Introduction As part of a larger study assessing the covariates and outcomes of GHB use, we developed a telephone-Survey Instrument for hospitalized GHB exposed patients identified through poison control center surveillance and for self-identified GHB users recruited from the general public. Methods We used an iterative review process with an interdisciplinary team, including pharmacists, a physician, and a medical anthropologist. In designing the structured, telephone-Survey Instrument, we prioritized inclusion of validated, drug-specific, and generic questionnaire batteries or individual items related to GHB or to other drugs of abuse. Only one published Survey Instrument specific to GHB use was identified, which we extensively expanded and modified. We also developed a number of GHB-specific items new to this Survey. Finally, we included items from the National Survey on Drug Use & Health, CAGE questionnaire items on alcohol abuse, the SF-12 Instrument, and selected National Health Interview items. Results The final questionnaire consisted of 272 content items, the majority of which required simple yes or no responses. The bulk of the items (74%) were GHB-specific. The questionnaire was easily administered using computer-assisted telephone interview (CATI) software. A total of 131 interviews were administered with a mean administration time of 33±10 minutes. The Instrument can also be used in other interview formats. Conclusion Developing a successful questionnaire calls for a multidisciplinary and systematic process. Structured, telephone administered Surveys are particularly suited to expand and explore the basic information obtained by poison centers for case management.
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Designing a gamma hydroxybutyrate (GHB) structured telephone-administered Survey Instrument.
Journal of medical toxicology : official journal of the American College of Medical Toxicology, 2007Co-Authors: Jo E. Dyer, Ilene B. Anderson, Susan Y. Kim, Judith C. Barker, Paul D. BlancAbstract:Introduction As part of a larger study assessing the covariates and outcomes of GHB use, we developed a telephone-Survey Instrument for hospitalized GHB exposed patients identified through poison control center surveillance and for self-identified GHB users recruited from the general public.
David R Ciardi - One of the best experts on this subject based on the ideXlab platform.
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observations of binary stars with the differential speckle Survey Instrument v toward an empirical metal poor mass luminosity relation
The Astronomical Journal, 2015Co-Authors: Elliott P Horch, William F Van Altena, Steve B Howell, David R Ciardi, Mark E Everett, Pierre Demarque, Johanna Teske, Todd J Henry, Jennifer G WintersAbstract:In an effort to better understand the details of the stellar structure and evolution of metal-poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and six stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. The mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory.
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observations of binary stars with the differential speckle Survey Instrument v toward an empirical metal poor mass luminosity relation
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Elliott P Horch, William F Van Altena, Steve B Howell, David R Ciardi, Mark E Everett, Pierre Demarque, Johanna Teske, Todd J Henry, Jennifer G WintersAbstract:In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and 6 stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. Mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory.
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observations of binary stars with the differential speckle Survey Instrument iii measures below the diffraction limit of the wiyn telescope
The Astronomical Journal, 2011Co-Authors: Elliott P Horch, William F Van Altena, William Sherry, Steve B Howell, David R CiardiAbstract:In this paper, we study the ability of CCD- and electron-multiplying-CCD-based speckle imaging to obtain reliable astrometry and photometry of binary stars below the diffraction limit of the WIYN 3.5 m Telescope. We present a total of 120 measures of binary stars, 75 of which are below the diffraction limit. The measures are divided into two groups that have different measurement accuracy and precision. The first group is composed of standard speckle observations, that is, a sequence of speckle images taken in a single filter, while the second group consists of paired observations where the two observations are taken on the same observing run and in different filters. The more recent paired observations were taken simultaneously with the Differential Speckle Survey Instrument, which is a two-channel speckle imaging system. In comparing our results to the ephemeris positions of binaries with known orbits, we find that paired observations provide the opportunity to identify cases of systematic error in separation below the diffraction limit and after removing these from consideration, we obtain a linear measurement uncertainty of 3-4 mas. However, if observations are unpaired or if two observations taken in the same filter are paired, it becomes harder to identify cases of systematic error, presumably because the largest source of this error is residual atmospheric dispersion, which is color dependent. When observations are unpaired, we find that it is unwise to report separations below approximately 20 mas, as these are most susceptible to this effect. Using the final results obtained, we are able to update two older orbits in the literature and present preliminary orbits for three systems that were discovered by Hipparcos.
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observations of binary stars with the differential speckle Survey Instrument ii hipparcos stars observed in 2010 january and june
The Astronomical Journal, 2011Co-Authors: Elliott P Horch, Shamilia C Gomez, William Sherry, Steve B Howell, David R Ciardi, Lisa M AndersonAbstract: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 3.5 m 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 1-2 mas in separation and better than 0°.6 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.
William F Van Altena - One of the best experts on this subject based on the ideXlab platform.
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observations of binary stars with the differential speckle Survey Instrument v toward an empirical metal poor mass luminosity relation
The Astronomical Journal, 2015Co-Authors: Elliott P Horch, William F Van Altena, Steve B Howell, David R Ciardi, Mark E Everett, Pierre Demarque, Johanna Teske, Todd J Henry, Jennifer G WintersAbstract:In an effort to better understand the details of the stellar structure and evolution of metal-poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and six stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. The mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory.
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observations of binary stars with the differential speckle Survey Instrument v toward an empirical metal poor mass luminosity relation
arXiv: Solar and Stellar Astrophysics, 2015Co-Authors: Elliott P Horch, William F Van Altena, Steve B Howell, David R Ciardi, Mark E Everett, Pierre Demarque, Johanna Teske, Todd J Henry, Jennifer G WintersAbstract:In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and 6 stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. Mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory.
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observations of binary stars with the differential speckle Survey Instrument iii measures below the diffraction limit of the wiyn telescope
The Astronomical Journal, 2011Co-Authors: Elliott P Horch, William F Van Altena, William Sherry, Steve B Howell, David R CiardiAbstract:In this paper, we study the ability of CCD- and electron-multiplying-CCD-based speckle imaging to obtain reliable astrometry and photometry of binary stars below the diffraction limit of the WIYN 3.5 m Telescope. We present a total of 120 measures of binary stars, 75 of which are below the diffraction limit. The measures are divided into two groups that have different measurement accuracy and precision. The first group is composed of standard speckle observations, that is, a sequence of speckle images taken in a single filter, while the second group consists of paired observations where the two observations are taken on the same observing run and in different filters. The more recent paired observations were taken simultaneously with the Differential Speckle Survey Instrument, which is a two-channel speckle imaging system. In comparing our results to the ephemeris positions of binaries with known orbits, we find that paired observations provide the opportunity to identify cases of systematic error in separation below the diffraction limit and after removing these from consideration, we obtain a linear measurement uncertainty of 3-4 mas. However, if observations are unpaired or if two observations taken in the same filter are paired, it becomes harder to identify cases of systematic error, presumably because the largest source of this error is residual atmospheric dispersion, which is color dependent. When observations are unpaired, we find that it is unwise to report separations below approximately 20 mas, as these are most susceptible to this effect. Using the final results obtained, we are able to update two older orbits in the literature and present preliminary orbits for three systems that were discovered by Hipparcos.
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observations of binary stars with the differential speckle Survey Instrument i Instrument description and first results
The Astronomical Journal, 2009Co-Authors: Elliott P Horch, Daniel R Veillette, Roberto Baena Galle, Sagar C Shah, Grant Orielly, William F Van AltenaAbstract:First results of a new speckle imaging system, the Differential Speckle Survey Instrument, are reported. The Instrument is designed to take speckle data in two filters simultaneously with two independent CCD imagers. This feature results in three advantages over other speckle cameras: (1) twice as many frames can be obtained in the same observation time which can increase the signal-to-noise ratio for astrometric measurements, (2) component colors can be derived from a single observation, and (3) the two colors give substantial leverage over atmospheric dispersion, allowing for subdiffraction-limited separations to be measured reliably. Fifty-four observations are reported from the first use of the Instrument at the Wisconsin-Indiana-Yale-NOAO 3.5 m Telescope9The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories. in 2008 September, including seven components resolved for the first time. These observations are used to judge the basic capabilities of the Instrument.
Jo E. Dyer - One of the best experts on this subject based on the ideXlab platform.
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Designing a gamma hydroxybutyrate (GHB) structured telephone-administered Survey Instrument
Journal of Medical Toxicology, 2007Co-Authors: Jo E. Dyer, Ilene B. Anderson, Susan Y. Kim, Judith C. Barker, Paul D. BlancAbstract:Introduction As part of a larger study assessing the covariates and outcomes of GHB use, we developed a telephone-Survey Instrument for hospitalized GHB exposed patients identified through poison control center surveillance and for self-identified GHB users recruited from the general public. Methods We used an iterative review process with an interdisciplinary team, including pharmacists, a physician, and a medical anthropologist. In designing the structured, telephone-Survey Instrument, we prioritized inclusion of validated, drug-specific, and generic questionnaire batteries or individual items related to GHB or to other drugs of abuse. Only one published Survey Instrument specific to GHB use was identified, which we extensively expanded and modified. We also developed a number of GHB-specific items new to this Survey. Finally, we included items from the National Survey on Drug Use & Health, CAGE questionnaire items on alcohol abuse, the SF-12 Instrument, and selected National Health Interview items. Results The final questionnaire consisted of 272 content items, the majority of which required simple yes or no responses. The bulk of the items (74%) were GHB-specific. The questionnaire was easily administered using computer-assisted telephone interview (CATI) software. A total of 131 interviews were administered with a mean administration time of 33±10 minutes. The Instrument can also be used in other interview formats. Conclusion Developing a successful questionnaire calls for a multidisciplinary and systematic process. Structured, telephone administered Surveys are particularly suited to expand and explore the basic information obtained by poison centers for case management.
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Designing a gamma hydroxybutyrate (GHB) structured telephone-administered Survey Instrument.
Journal of medical toxicology : official journal of the American College of Medical Toxicology, 2007Co-Authors: Jo E. Dyer, Ilene B. Anderson, Susan Y. Kim, Judith C. Barker, Paul D. BlancAbstract:Introduction As part of a larger study assessing the covariates and outcomes of GHB use, we developed a telephone-Survey Instrument for hospitalized GHB exposed patients identified through poison control center surveillance and for self-identified GHB users recruited from the general public.
