1,729,770 research outputs found
NGC 2659: a probable binary cluster
Get PDFPresentamos y discutimos datos fotométricos, movimientos propios y paralajes en un campo de 30’x30’ centrado en el área ocupada por el cúmulo abierto NGC 2659 en la región de Vela. En trabajos recientes sobre la misma región se han reportado evidencias de la presencia de otro cúmulo cerca del noreste de NGC 2659.
Los datos se extrajeron de Gaia EDR3 y se emplearon en combinación con el paquete ASteCA para investigar la estructura dimensional de la región ocupada por este grupo. Sorprendentemente, al combinar paralajes y movimientos propios, identificamos dos grupos de estrellas superpuestos a lo largo de la línea de visión y separados entre sí por aproximadamente 100 pe, en lugar de solo uno como se sugiere en la literatura pasada y presente.
Uno de ellos, el más joven, se identificó históricamente como NGC 2659, mientras que el otro es un cúmulo abierto relativamente viejo que cubre un área más grande pero se ubica frente a NGC 2659 y se lo identifica como Pismis 9. Después de evaluar la pertenencia a grupos individuales, derivamos su cinemática (componentes del movimiento propio medio), distancias, edades y también el contenido de metales.We present and discuss photometric data, proper motions and parallaxes in a field of a 30’x30’ centred in the area centered in the open cluster NGC 2659 in the region of Vela. In recent papers on the same region evidences of the presence of another cluster close to the north-east of NGC 2659 have been reported. Data were extracted from Gaia EDR3 and have been employed in combination with ASteCA package to investigate the dimensional structure of the region occupied by this cluster. Surprisingly, by combining parallaxes and proper motions we identify two star groups superposed along the line of sight, and separated from each other by about 100 pc, instead of just one as suggested in the past and present literature. One of them, the younger one, has been historically identified as NGC 2659 while the other is a relatively old open cluster covering a larger area but placed in front of NGC 2659 and is identified as Pismis 9. After assessing individual group membership, we derive their kinematics (mean proper motion components), distances, ages and also the metal content.Asociación Argentina de AstronomíaInstituto de Astrofísica de La Plat
NGC 2659: a probable binary cluster
Get PDFPresentamos y discutimos datos fotométricos, movimientos propios y paralajes en un campo de 30’x30’ centrado en el área ocupada por el cúmulo abierto NGC 2659 en la región de Vela. En trabajos recientes sobre la misma región se han reportado evidencias de la presencia de otro cúmulo cerca del noreste de NGC 2659.
Los datos se extrajeron de Gaia EDR3 y se emplearon en combinación con el paquete ASteCA para investigar la estructura dimensional de la región ocupada por este grupo. Sorprendentemente, al combinar paralajes y movimientos propios, identificamos dos grupos de estrellas superpuestos a lo largo de la línea de visión y separados entre sí por aproximadamente 100 pe, en lugar de solo uno como se sugiere en la literatura pasada y presente.
Uno de ellos, el más joven, se identificó históricamente como NGC 2659, mientras que el otro es un cúmulo abierto relativamente viejo que cubre un área más grande pero se ubica frente a NGC 2659 y se lo identifica como Pismis 9. Después de evaluar la pertenencia a grupos individuales, derivamos su cinemática (componentes del movimiento propio medio), distancias, edades y también el contenido de metales.We present and discuss photometric data, proper motions and parallaxes in a field of a 30’x30’ centred in the area centered in the open cluster NGC 2659 in the region of Vela. In recent papers on the same region evidences of the presence of another cluster close to the north-east of NGC 2659 have been reported. Data were extracted from Gaia EDR3 and have been employed in combination with ASteCA package to investigate the dimensional structure of the region occupied by this cluster. Surprisingly, by combining parallaxes and proper motions we identify two star groups superposed along the line of sight, and separated from each other by about 100 pc, instead of just one as suggested in the past and present literature. One of them, the younger one, has been historically identified as NGC 2659 while the other is a relatively old open cluster covering a larger area but placed in front of NGC 2659 and is identified as Pismis 9. After assessing individual group membership, we derive their kinematics (mean proper motion components), distances, ages and also the metal content.Asociación Argentina de AstronomíaInstituto de Astrofísica de La Plat
Dean, Harry Moseley, 1884-1958 (SC 2659)
Get PDFFinding aid only for Manuscripts Small Collection 2659. A volume of Harry Moseley Dean\u27s poetry compiled by Gayle R. Carver
Block Card 2659 Southwood Road
No full textThis image was produced by the Auditor's Office in Lucas County, Ohio for tax assessment purposes. Associated dates are approximate. Descriptive terms related to this photograph include: Craftsman Style | 2659 Southwood Road (Toledo, Ohio) | Dwelling | Southwood Park Addition (Toledo, Ohio) | South Toledo Area (Toledo, Ohio
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
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
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