1,721,209 research outputs found
Detection and characterisation of a 106-day transiting Jupiter : TOI-2449 b / NGTS-36 b
No full textUlmer-Moll, S. et al.[Context] Only a handful of transiting giant exoplanets with orbital periods longer than 100 days are known. These warm exoplanets are valuable objects, as their radius and mass can be measured and lead to an in-depth characterisation of the planet’s properties. Thanks to low levels of stellar irradiation and large orbital distances, the atmospheric properties and orbital parameters of warm exoplanets remain relatively unaltered by their host star, giving new insights into planetary formation and evolution.[Aims] Our aim is to increase the sample of warm giant exoplanets with precise radii and masses. Our goal is to identify suitable candidates in the Transiting Exoplanet Survey Satellite data and perform follow-up observations with ground-based instruments.[Methods] We used the Next Generation Transit Survey (NGTS) to detect additional transits of planetary candidates in order to pinpoint their orbital period. We also monitored the target with several high-resolution spectrographs to measure the planetary mass and eccentricity. We studied the planet’s interior composition with a planetary evolution code to determine the planet’s metallicity.[Results] We report the discovery of a 106-day period Jupiter-sized planet around the G-type star TOI-2449/NGTS-36. We jointly modelled the photometric and radial velocity data and find that the planet has a mass of 0.70−0.04+0.05 MJ and a radius of 1.001 ± 0.009 RJ. The planetary orbit has a semi-major axis of 0.449 au and is slightly eccentric (e = 0.0098−0.030+0.028). We detected an additional 3-year signal in the radial velocity data that is likely due to the stellar magnetic cycle. Based on the planetary evolution models considered here, we find that TOI-2449 b/NGTS-36 b contains 11−5+6 M⊕ of heavy elements and has a marginal planet-to-star metal enrichment of 3.3−1.8+2.5. Assuming a Jupiter-like bond albedo, TOI-2449 b/NGTS-36 b has an equilibrium temperature of 400 K and is a good target for understanding nitrogen chemistry in cooler atmospheres.This work has been carried out within the framework of the National Centre of Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF) under grants 51NF40_182901 and 5INF40_205606. The authors acknowledge the financial support of the SNSF This work is based on data collected under the NGTS project at the ESO Paranal Observatory. The NGTS facility is operated by a consortium institutes with support from the UK Science and Technology Facilities Council (STFC) under projects ST/M001962/1, ST/S002642/1 and ST/W003163/1. The contributions at the University of Warwick by SG, DB, PJW, RGW and DA have been supported by STFC through consolidated grants ST/P000495/1, STT000406/1 and ST/X001121/1. KA acknowledges support from the SNSF under the Post-doc Mobility grant P500PT_230225. ML acknowledges support of the SNSF under grant number PCEFP2194576. This paper made use of data collected by the TESS mission and are publicly available from the Mkulski Archive for Space Telescopes (MAST) operated by the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by NASA’s Science Mission Directorate. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Super-computing (NAS) Division at Ames Research Center for the production of the SPOC data products. KAC acknowledges support from the TESS mission via subaward s3449 from MIT. R.B. acknowledges support from FONDECYT Project 1241963 and from ANID – Millennium Science Initiative – ICNI2_009. This work was funded by the Data Observatory Foundation. A.De. acknowledges financial support from the Swiss National Science Foundation (SNSF) for project 200021_200726. A.J. acknowledges support from ANID – Mllennium Science Initiative – ICNI2_009, AIM23-0001 and from FONDECYT project 1210718. M.T.P. acknowledges support from Fondecyt-ANID fellowship no. 3210253 and ASTRON-0037. A.P acknowledges support from the Unidad de Excelencia María de Maeztu CEX2020-001058-M programme and from the Generalitat de Catalunya/CERCA. The results reported herein benefitted from collaborations and/or information exchange within NASA’s Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA’s Science Mission Directorate under Agreement No. 80NSSC21K0593 for the program “Alien Earths”. GV has received support from the European Research Council (ERC) under the European Union s Horizon 2020 research and innovation programme (Grant Agreement No. 947660). Some of the observations in this paper made use of the High-Resolution Imaging instrument Zorro and were obtained under Gemini LLP Proposal Number: GN/S-2021A-LP-105. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini South telescope of the international Gemini Observatory, a program of NSF’s OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). C.A.W. would like to acknowledge support from the UK Science and Technology Facilities Council (STFC, grant number ST/X00094X/1). JSJ greatfully acknowledges support by FONDECYT grant 1240738 and from the ANID BASAL project FB210003. The contributions at the Mullard Space Science Laboratory by EMB have been supported by STFC through the consolidated grant ST/W001136/1. TR is supported by an STFC studentship.With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (CEX2020-001058-M)Peer reviewe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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