1,721,487 research outputs found
Characterization of the HD 17156 Planetary System
Get PDFAims. We present data to improve the known parameters of the HD 17156 system (peculiar due to the eccentricity and long orbital period of its transiting planet) and constrain the presence of stellar companions.
Methods. Photometric data were acquired for 4 transits, and high precision radial velocity measurements were simultaneously acquired with the SARG spectrograph at TNG for one transit. The template spectra of HD 17156 was used to derive effective temperature, gravity, and metallicity. A fit of the photometric and spectroscopic data was performed to measure the stellar and planetary radii, and the spin-orbit alignment. Planet orbital elements and ephemeris were derived from the fit. Near infrared adaptive optic images were acquired with the AdOpt module of TNG.
Results. We found that the star has a radius of RS = 1.440.03 and the planet RP = 1.020.08 RJ. The transit ephemeris is Tc = 2 454 756.73134 0.00020 + N 21.21663 0.00045 BJD. Analysis of the Rossiter-Mclaughlin effect shows that the system is spin orbit aligned with an angle = 4.8°5.3°. The analysis of high resolution images did not reveal any stellar companion with a projected separation between of 150 and 1 000 AU from HD 17156.AstronomyAccepted Manuscrip
Improved Measurement of the Rossiter-McLaughlin Effect in the Exoplanetary System HD 17156
Get PDFWe present an improved measurement of the Rossiter-McLaughlin effect for the exoplanetary system HD 17156, based on radial-velocity data gathered with the Subaru 8.2m telescope throughout the planetary transit of UT 2008 November 7. The data allow for a precise and independent determination of the projected spin-orbit angle of this system: λ = 10[° over .]0 ± 5[° over .]1. This result supersedes the previous claim of λ = 62° ± 25° by Narita et al., which was based on lower-precision data with poor statistics. Thus the stellar spin and planetary orbital axes of the HD 17156 system are likely to be well-aligned, despite the planet's large orbital eccentricity suggesting a history of strong dynamical interactions
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Coordinated X-Ray and Optical Observations of Star-Planet Interaction in HD 17156
Get PDFA.M. and the GAPS project team acknowledge support from the “Progetti Premiali” funding scheme of the Italian Ministry of Education, University, and Research. I.P. acknowledges support from the European Union Seventh Framework Programme FP7/2007–2013, under the grant agreement No. 267251 “Astronomy Fellowships in Italy” (AstroFIt). Facilities: XMM-Newton (EPIC) , TNG (HARPS-N) .The large number of close-in Jupiter-size exoplanets prompts the question whether star-planet interaction (SPI) effects can be detected. We focused our attention on the system HD 17156, having a Jupiter-mass planet in a very eccentric orbit. Here we present results of the XMM-Newton observations and of a five month coordinated optical campaign with the HARPS-N spectrograph. We observed HD 17156 with XMM-Newton when the planet was approaching the apoastron and then at the following periastron passage, quasi-simultaneously with HARPS-N. We obtained a clear (≈ 5.5σ ) X-ray detection only at the periastron visit, accompanied by a significant increase of the R'_HK chromospheric index. We discuss two possible scenarios for the activity enhancement: magnetic reconnection and flaring or accretion onto the star of material tidally stripped from the planet. In any case, this is possibly the first evidence of a magnetic SPI effect caught in action.A.M. and the GAPS project team acknowledge support from the “Progetti Premiali” funding scheme of the Italian Ministry of Education, University, and Research. I.P. acknowledges support from the European Union Seventh Framework Programme FP7/2007–2013, under the grant agreement No. 267251 “Astronomy Fellowships in Italy” (AstroFIt)
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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