1,720,980 research outputs found
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. III. Aperture Masking Interferometric Observations of the Star HIP 65426 at 3.8μm
No full textRay, Shrishmoy et al.-- Full list of authors: Ray, Shrishmoy; Sallum, Steph; Hinkley, Sasha; Sivaramkrishnan, Anand; Cooper, Rachel; Kammerer, Jens; Greebaum, Alexandra Z.; Thatte, Deeparshi; Stolker, Tomas; Lazzoni, Cecilia; Tokovinin, Andrei; de Furio, Matthew; Factor, Samuel; Meyer, Michael; Stone, Jordan M.; Carter, Aarynn; Biller, Beth; Skemer, Andrew; Suárez, Genaro; Leisenring, Jarron M.; Perrin, Marshall D.; Kraus, Adam L.; Absil, Olivier; Balmer, William O.; Boccaletti, Anthony; Bonavita, Mariangela; Bonnefoy, Mickael; Booth, Mark; Bowler, Brendan P.; Briesemeister, Zackery W.; Bryan, Marta L.; Calissendorff, Per; Cantalloube, Faustine; Chauvin, Gael; Chen, Christine H.; Choquet, Elodie; Christiaens, Valentin; Cugno, Gabriele; Currie, Thayne; Danielski, Camilla; Dupuy, Trent J.; Faherty, Jacqueline K.; Fitzgerald, Michael P.; Fortney, Jonathan J.; Franson, Kyle; Girard, Julien H.; Grady, Carol A.; Gonzales, Eileen C.; Henning, Thomas; Hines, Dean C.; Hoch, Kielan K. W.; Hood, Callie E.; Howe, Alex R.; Janson, Markus; Kalas, Paul; Kennedy, Grant M.; Kenworthy, Matthew A.; Kervella, Pierre; Kuzuhara, Masayuki; Lagrange, Anne-Marie; Lagage, Pierre-Olivier; Lawson, Kellen; Lew, Ben W. P.; Liu, Michael C.; Liu, Pengyu; Llop-Sayson, Jorge; Lloyd, James P.; Macintosh, Bruce; Marino, Sebastian; Marley, Mark S.; Marois, Christian; Martinez, Raquel A.; Matthews, Brenda C.; Matthews, Elisabeth C.; Mawet, Dimitri; Mazoyer, Johan; McElwain, Michael W.; Metchev, Stanimir; Meyer, Michael R.; Miles, Brittany E.; Millar-Blanchaer, Maxwell A.; Molliere, Paul; Moran, Sarah E.; Morley, Caroline V.; Mukherjee, Sagnick; Palma-Bifani, Paulina; Pantin, Eric; Patapis, Polychronis; Petrus, Simon; Pueyo, Laurent; Quanz, Sascha P.; Quirrenbach, Andreas; Rebollido, Isabel; Adams Redai, Jea; Ren, Bin B.; Rickman, Emily; Samland, Matthias; Schlieder, Joshua E.; Schneider, Glenn; Stapelfeldt, Karl R.; Tamura, Motohide; Tan, Xianyu; Uyama, Taichi; Vigan, Arthur; Vasist, Malavika; Vos, Johanna M.; Wagner, Kevin; Wang, Jason J.; Ward-Duong, Kimberly; Whiteford, Niall; Wolff, Schuyler G.; Worthen, Kadin; Wyatt, Mark C.; Ygouf, Marie; Zhang, Xi; Zhang, Keming; Zhang, Zhoujian; Zhou, Yifan; Zurlo, Alice; Sargent, B. A.; Theissen, Christopher A.; Manjavacas, Elena; Lueber, Anna; Kitzmann, Daniel; Sutlieff, Ben J.; Betti, Sarah K.We present aperture masking interferometry (AMI) observations of the star HIP 65426 at 3.8 μm, as part of the JWST Direct Imaging Early Release Science program, obtained using the Near Infrared Imager and Slitless Spectrograph instrument. This mode provides access to very small inner working angles (even separations slightly below the Michelson limit of 0.5λ/D for an interferometer), which are inaccessible with the classical inner working angles of the JWST coronagraphs. When combined with JWST's unprecedented infrared sensitivity, this mode has the potential to probe a new portion of parameter space across a wide array of astronomical observations. Using this mode, we are able to achieve a 5σ contrast of ΔmF380M ∼ 7.62 ± 0.13 mag relative to the host star at separations ≳0
07, and the contrast deteriorates steeply at separations ≲0
07. However, we detect no additional companions interior to the known companion HIP 65426b (at separation ∼0
82 or
). Our observations thus rule out companions more massive than 10–12 MJup at separations ∼10–20 au from HIP 65426, a region out of reach of ground- or space-based coronagraphic imaging. These observations confirm that the AMI mode on JWST is sensitive to planetary mass companions at close-in separations (≳0
07), even for thousands of more distant stars at ∼100 pc, in addition to the stars in the nearby young moving groups and associations, as stated in previous works. This result will allow the planning and successful execution of future observations to probe the inner regions of nearby stellar systems, opening an essentially unexplored parameter space. © 2025. The Author(s).This work is based on observations made with the NASA/
ESA/CSA JWST and obtained from the Mikulski Archive for
Space Telescopes at the Space Telescope Science Institute. The
specific observations analyzed can be accessed via 10.17909/
8by2-x206. We are truly grateful for the countless hours that
thousands of people have devoted to the design, construction,
and commissioning of JWST. We thank the anonymous referee
for comments that have been crucial toward the improvement
of this Letter. This project was supported by a grant from
STScI (JWST-ERS-01386) under NASA contract NAS5-
03127. S.R. was supported by the Global Excellence Award
at the University of Exeter. This work is based in part on
observations obtained at the Southern Astrophysical Research
(SOAR) telescope, which is a joint project of the Ministério da
Ciência, Tecnologia e Inovações (MCTI/LNA) of Brasil, the
US National Science Foundation’s NOIRLab, the University of
North Carolina at Chapel Hill (UNC), and Michigan State
University (MSU). This work has also made use of the
SPHERE Data Centre, jointly operated by OSUG/IPAG
(Grenoble), PYTHEAS/LAM/CeSAM (Marseille), OCA/
Lagrange (Nice), Observatoire de Paris/LESIA (Paris), and
Observatoire de Lyon/CRAL, as well as being supported by a
grant from Labex OSUG@2020 (Investissements d’avenir—
ANR10 LABX56). This work has benefited from the 2022
Exoplanet Summer Program in the Other Worlds Laboratory
(OWL) at the University of California, Santa Cruz, a program
funded by the Heising–Simons Foundation.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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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