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We examine high-resolution follow-up imaging data for 84 KOIs with stellar companions detected within 2”. These stars were observed in the optical using speckle interferometry (Gemini/DSSI or WIYN/DSSI) and/or in the near-infrared with adaptive optics imaging (Keck/NIRC2, Palomar/PHARO, or Lick/IRCAL), and all have imaging results in at least two filters. Their companions are all unresolved in the Kepler images, and fall on the same pixel of the Kepler detector; thus the planet radii calculated for planet candidates in these systems are subject to upward revision due to contamination of the target star’s light by the stellar companion. We calculate updated planet radii for these 84 planet candidates, assuming the planet orbits the brighter of the two stars. We also use isochrone models and distance estimates to assess the likelihood that the companion is bound. This analysis complements galaxy models that determine the probability of a chance alignment of a background star for each system (Everett et al., in prep.). Together, these data allow us to isolate a sub-population of Kepler planets and planet candidates that reside in physical binary systems, for comparison to the wider Kepler planet population.
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The NASA K2 mission is finding many high-value exoplanets and world-wide follow-up is ensuing. The NASA TESS mission will soon be launched, requiring additional ground-based observations as well. As a part of the NASA-NSFNN-EXPLORE program to enable exoplanet research, our group is building two new speckle interferometry cameras for the Kitt Peak WIYN 3.5-m telescope and the Gemini-N 8-m telescope. Modeled after the successful DSSI visitor instrument that has been used at these telescopes for many years, speckle observations provide the highest resolution images available today from any ground- or space-based single telescope. They are the premier method through which small, rocky exoplanets can be validated. Available for public use in early 2017, WIYNSPKL and GEMSPKL will obtain simultaneous images in two filters with fast EMCCD readout, "speckle" and “wide-field” imaging modes, and user support for proposal writing, observing, and data reduction. We describe the new cameras, their design, and their benefits for exoplanet follow-up, characterization, and validation. Funding for this project comes from the NASA Exoplanet Exploration Program and NASA HQ.
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The high-spatial-resolution technique of speckle interferometry has been in use at Lowell Observatory's Discovery Channel Telescope since 2014 with the Dual-channel Stellar Speckle Imager (DSSI; Horch et al. 2009) as a visiting instrument. Using its standard bandpasses of 692 and 880nm, we have used highly efficient DSSI instrument to inspect over a thousand stellar systems over the course of 2014 (Horch et al. 2015). We have also demonstrated the usefulness of the DSSI@DCT system for resolved observations of high-altitude (>1,000 miles) man-made satellites in highly non-sidereal rate orbits.
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The Lowell Observatory Discovery Channel Telescope (DCT) has been in full science operation for 2 years (2015 and 2016). Five instruments have been commissioned during that period, and two additional instruments are planned for 2017. These include:+ Large Monolithic Imager (LMI) - a CCD imager (12.6 arcmin FoV)+ DeVeny - a general purpose optical spectrograph (2 arcmin slit length, 10 grating choices)+ NIHTS - a low resolution (R=160) YJHK spectrograph (1.3 arcmin slit)+ DSSI - a two-channel optical speckle imager (5 arcsec FoV)+ IGRINS - a high resolution (45,000) HK spectrograph, on loan from the University of Texas.In the upcoming year, instruments will be delivered from the University of Maryland (RIMAS - a YJHK imager/spectrograph) and from Yale University (EXPRES - a very high resolution stabilized optical echelle for PRV).Each of these instruments will be described, along with their primary science goals.
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How many K dwarfs have “kids?” Stellar multiplicity fractions have been obtained for most spectral types, most recently by Raghavan et al. (2010) and Winters et al. (2015), finding rates of 50% for solar-type stars and 27% for M dwarfs, respectively. These findings will be crucial to improving our understanding of solar-system formation, but there has not yet been a statistically significant survey for K dwarfs to bridge the gap between G and M stars. To create a sample for a robust multiplicity survey, an initial set of 1048 K dwarfs was built using the Hipparcos and 2MASS catalogs, the companions of which are called “K-KIDS.” Future releases from Gaia will help us to expand K-KIDS into a volume-complete sample out to 50-pc, and we project that the final sample will contain over 3000 stars, making this the largest volume-complete multiplicity survey ever undertaken. For observational purposes, the targeted K dwarfs are confined equatorially to -30 < DEC < +30 to ensure all stars are observable from either hemisphere. The survey for K-KIDS is split into three companion-separation regimes: small (0.02 - 2.00 arcseconds), medium (2.00 - 10.00 arcseconds), and distant (10.00+ arcseconds). Small separation companions are resolved using the Differential Speckle Survey Instrument, with which we have observed 964 out of 1048 systems to date, already finding 135 new K-KIDS. Medium separation companions are observed via a series of three observations per star at the CTIO 0.9-m telescope, integrating for 3, 30, and 300 seconds to reveal companions of various brightnesses. Finally, a common proper-motion search is used to find companions at distant separations via blinking of digitialized images in the SuperCOSMOS archive, in addition to a large-scale literature survey for previously-discovered multiples. The small and distant surveys are nearing completion, and continued progress on the medium survey ensures that a statistically significant multiplicity rate for K dwarfs will soon be in achieved. Furthermore, a new RV survey is planned using the CHIRON high-resolution spectrograph to find companions that cannot be directly imaged. This effort has been supported by the NSF through grants AST-1412026 and AST-1517413.
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We have added references to Tables 3 and 8 (last column in each table). Below is a sample of both tables; the full tables are available in machine-readable form.
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Speckle interferometry at Yale started in 1994 with a three-year program of observations at the Yale Southern Observatory at El Leoncito, Argentina. After this experience, we began a long-term program of speckle observations at the WIYN 3.5-m telescope at Kitt Peak National Observatory, first using a MAMA detector, then CCD and finally EMCCD technology. We describe the evolution of the program, its main results in terms of discovered components, orbital parameters and masses. While the Yale program ended in 2013, it provided the springboard for continued speckle efforts at WIYN, the Discovery Channel 4.3-m Telescope, and the Gemini 8.1-m Telescopes for binary star research, exoplanet science, and other projects. An important outcome of this research will be the incorporation of the soon to be released high-precision Gaia parallaxes into our observations.
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We present preliminary fundamental stellar parameters and multiplicity rates of M dwarf stars using a combination of speckle imaging and adaptive optics. Our survey mainly uses the Differential Speckle Survey Instrument (DSSI) at Lowell Observatory's Discovery Channel Telescope (DCT). DSSI observes speckle patterns simultaneously at two separate wavelengths and the data for this project are composed of observations which span from 2016 to 2018. More recently, the speckle data for some of the target stars that have been found to be binary have been supplemented with observations using Adaptive Optics (AO) at Palomar Observatory. The combination of speckle data in the visible and AO data in the near-infrared allows us to make robust determinations of the luminosities and effective temperatures of the components in each case. Using the known Mass-Luminosity Relation, we also estimate the component masses. A discussion of interesting systems will be given.
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While at first glance multi-star systems seem quite extreme, they are in fact the most common type of star system in our galaxy, throughout the stellar mass distribution. In particular, 40 to 50% of exoplanet host stars reside within multiple star systems. Given the degree to which initially undetected multiplicity has skewed Kepler results, high-resolution imaging of our nearby low-mass neighbors is necessary for both accurate characterization of transiting exoplanets, as well as a better understanding of stellar astrophysics. To address this frequent gap in our knowledge of exoplanet hosts, we will utilize speckle interferometry to directly image TESS exoplanet host candidates to complete our knowledge of individual star multiplicity. Our investigation will expand upon the speckle observations taken as a part of the POKEMON speckle survey of nearby M-dwarfs to better constrain the multiplicity of low-mass TESS exoplanet host candidates, and to constrain M-dwarf multiplicity by subtype across the entire M-dwarf sequence.
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QWSSI, the Quad-camera Wavefront-Sensing Speckle Imager, is a next-generation speckle imager that is being developed for Lowell Observatory's 4.3-meter Discovery Channel Telescopes. The principle behind QWSSI is to extend the capabilities of the speckle camera currently resident at Lowell, the Differential Speckle Survey Instrument (DSSI), in two ways. First, while DSSI currently observes in two visible channels, QWSSI will simultaneously observe in six narrow-band channels: four in the visible (0.5-0.9um), and one each in J- and H-band (1.2 and 1.6um). Second, the visible light unused for speckle imaging is carefully preserved and feeds a wavefront sensor (WFS), which is also run simultaneously with the speckle imaging. Simulations by Löbb (2016) indicate WFS data will provide significant gains in exploring stellar multiplicity, with marked improvements in primary-secondary contrast ratios and inner working angle (Horch et al. 2018). QWSSI will also be mountable on one of the three 1-meter telescopes being installed on the NPOI Array for engineering tests and preliminary science observations. QWSSI will expand on the already considerable exoplanetary work of the speckle imagers DSSI, NESSI (@ WIYN), Alopeke (Gemini-N), and Zorro (Gemini-S), improving the discovery space for existing targets, as well opening up new regions of that discovery space with its NIR channels.
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A program of speckle observations at Lowell Observatory's Discovery Channel Telescope (DCT) and the Gemini North and South Telescopes will be described. It has featured the Differential Speckle Survey Instrument (DSSI), built at Southern Connecticut State University in 2008. DSSI is a dual-port system that records speckle images in two colors simultaneously and produces diffraction limited images to V∼ 16.5 mag at Gemini and V∼ 14.5 mag at the DCT. Of the several science projects that are being pursued at these telescopes, three will be highlighted here. The first is high-resolution follow-up observations for Kepler and K2 exoplanet missions, the second is a study of metal-poor spectroscopic binaries in an attempt to resolve these systems and determine their visual orbits en route to making mass determinations, and the third is a systematic survey of nearby late-type dwarfs, where the multiplicity fraction will be directly measured and compared to that of G dwarfs. The current status of these projects is discussed and some representative results are given.
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The Southern Connecticut Stellar Interferometer is an astronomical intensity interferometer consisting of two telescopes. Each is currently equipped with a single-photon avalanche diode (SPAD) detector, and an ultra-fast timing module correlates counts between both photon detectors. The interferometer has previously demonstrated intensity correlations using the 1-pixel SPADs and extremely narrow band pass filters but was limited in the amount of light that could be collected, and therefore the signal-to-noise ratio that could be achieved. SCSU's recent acquisition of an 8-pixel SPAD detector has allowed for a new possibility: a different wavelength of light could be directed towards each of the 8 pixels of the detector, thus conducting 8 independent intensity interferometry experiments at the same time, if this could be implemented at both telescopes. Using materials and resources available in the Astronomical Instrumentation Laboratory at Southern Connecticut State University, an optical system has been developed to work toward this goal but outfitting the first telescope in this way. The light from the telescope is collimated and directed toward a reflective diffraction grating. This is then re-imaged using a second lens and directed onto the pixels of the photon detector. These optical components have been placed inside an aluminum housing and can be mounted to the telescope for test observations. A status report will be given on the observations so far. If this can be replicated at the other telescope, the signal-to-noise ratio achievable with the instrument could be improved by a factor of 2.8.
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This article explores the narrative of parliamentary history in fifteenth-century England, specifically as found in the texts William Caxton printed. It investigates Caxton's approach to history and motivation for choosing texts, his translations and vocabulary, his editorial oversight and his audience. As his confidence in his own skill grew, and as he moved from a continental to an English context, his reading of parliaments changed. Initially it corresponded to his French texts, but by the early 1480s he understood the term ‘parliament’ to mean some variation of the contemporary English Parliament. Caxton's later understanding is reflected in the histories he published. This article emphasises the importance of Caxton's historical narratives to Parliament's legitimacy and to political discourse in a time when few parliaments were held.
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In Black Women Speaking From Within: Essays and Experiences in Higher Education, contributors use intersectional and interdisciplinary lenses to share the ways in which they understand, navigate, resist, and transform student services, learning, teaching, and existing in the academy. This book explores and discusses the following question: How do Black women experience and perceive place and agency in higher education? Black Women Speaking From Within draws upon the influence organizational culture, sense-making, and sisterhood has on praxis and pedagogy and places the Black woman’s stories and experiences at the center of the conversation.
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Abstract It is clear that there is an increasing proportion of the United Kingdom (UK) population who are suffering with food allergies and this combined with an increase in the frequency of eating away from home (where there is less control over the content of food) poses a significant risk. In December 2014, the European Union (EU) introduced legislation which aimed to ensure that customers with food allergens could make informed choices and safely consume food, without the risk of a potentially life-threatening reaction. The research used semi-structured interviews with staff from a BCB, located in the North West of the UK, as the aim of the research was to explore food handlers’ knowledge, attitudes and understanding of food allergens. The findings of the semi-structured interviews identified five themes: E-learning training programmes: the staff felt that these were ineffective and did not take into account individual learning styles. Responsibility: there is a lack of clarity as to who is responsible, with staff believing the key responsibility lies with the customer. Communication: similarly, communication, both within the kitchen and within the company was not clear and likely to give rise to confusion. Need to make a profit: the staff felt that the drive for profit meant that customer safety was being compromised, especially when staff numbers were reduced. Staff awareness: the staff felt confident in their own ability to prepare a safe meal but indicated that staff may be dismissive towards claims of allergen sufferers. In conclusion, these themes illustrate that a significant risk exists for allergen suffers, who rely upon the knowledge, attitudes and understanding of BCB staff to ensure their meals are safely prepared.
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Human service organizations seek bilingual professionals to meet the social and linguistic needs of their increasingly limited English proficient (LEP) clientele. As a result, bilingual professionals often find themselves having to meet overwhelming service delivery expectations. This paper reports on a qualitative study about the work experiences of 27 court employees within a judicial system in the Eastern United States. The study found that bilingual professionals encounter challenges because of their language skills. At the intersection of these challenges are microaggressions that manifest in the judicial system, adversely affecting them professionally and personally.
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The adapted physical educator (APE) at this high school has a tenth grader with epilepsy in his class. The student is assigned a paraprofessional to monitor and assist him. The APE plans an indoor soccer lesson, which allows for easier participation for another student in a wheelchair, as well as better monitoring for the student with epilepsy. With the lesson underway and the paraprofessional positioned nearby, the student has a seizure. Fortunately, the APE has had some training on recognizing seizures, and the paraprofessional is there to help. Wondering what would happen if they were not there when the student began having a seizure and how to explain it to the other students, the APE creates a seizure fact and protocol sheet.
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