Results 21 to 30 of about 1,487,013 (249)
The lithium abundance of M67 blue stragglers - A constraint on the blue straggler phenomenon
Upper limits have been placed on the line strength of the 6707 A Li I resonance doublet in seven blue stragglers in M67. The corresponding upper limits on abundances range from log N(Li) less than about 1.3 to less than about 2.3. This result is significantly below the level of log N(Li) about 3.1 + or {minus} 0.1 found in field main-sequence stars of ...
C. J. Pritchet, J. W. Glaspey
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Blue stragglers in open clusters [PDF]
We performed for the rst time a detailed LTE spectroscopic study of a sample of blue straggler stars in the moderately old open cluster NGC 7789. For eight stars the parameters and abundances of several elements were determined. The cluster members show a remarkable surface magnesium deciency which is quite unusual for late B - early A stars.
D. Schönberner +2 more
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Blue Straggler Stars in Globular Clusters: A Powerful Tool to Probe the Internal Dynamical Evolution of Stellar Systems [PDF]
This chapter presents an overview of the main observational results obtained to date about Blue Straggler Stars (BSSs) in Galactic Globular Clusters (GCs).
Alessio Mucciarelli +10 more
core +1 more source
Blue Straggler Formation in Clusters [PDF]
Blue stragglers are thought to be formed from the merger or coalescence of two stars, but the details of their formation in clusters has been difficult to disentangle. We discuss the two main formation mechanisms for blue stragglers (stellar collisions or mass transfer in a binary system).
Alison Sills +2 more
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Blue straggler stars in Galactic open clusters and the effect of field star contamination [PDF]
Context: We investigate the distribution of blue straggler stars in the field of three open star clusters. Aims: The main purpose is to highlight the crucial role played by general Galactic disk fore-/back-ground field stars, which are often located in ...
Moitinho, A. +7 more
core +1 more source
The Blue Straggler F190: A Case for Mass Transfer [PDF]
The blue straggler F190 is a member of the old open cluster M67. We argue that F190 may still be in the final stages of the mass transfer that has made it into a blue straggler. We use the turnoff mass of the cluster and the mass function derived from the spectroscopic orbit for F190 to constrain the masses of each member of the binary, both before ...
Alejandra A. E. Milone, David W. Latham
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Young blue straggler stars in the Galactic field [PDF]
In this study we present an analysis of a sample of field blue straggler (BS) stars that show high ultra violet emission in their spectral energy distributions (SED): indication of a hot white dwarf (WD) companion to BS. Using photometry available in the Sloan Digital Sky Survey (SDSS) and Galaxy Evolution Explorer (GALEX ) surveys we identified 80 ...
Ekanayake, Gemunu, Wilhelm, Ronald
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FORMATION AND EVOLUTION OF BLUE STRAGGLERS IN 47 TUCANAE [PDF]
ABSTRACT Blue stragglers (BSS) are stars whose position in the color–magnitude diagram (CMD) places them above the main sequence (MS) turn-off (TO) point of a star cluster. Using data from the core of 47 Tuc in the ultraviolet (UV), we have identified various stellar populations in the CMD, and used their radial distributions to study ...
Javiera Parada +4 more
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Chemical composition of a palomar 12 blue straggler
ABSTRACT With the equivalent area of a 16-m telescope, ESPRESSO in 4UT mode allows to inaugurate high resolution spectroscopy for solar-type stars belonging to extragalactic globular clusters. We determine the chemical composition of an extragalactic blue straggler (BS).
L Pasquini +7 more
openaire +4 more sources
Blue Straggler Bimodality: A Brownian Motion Model [PDF]
Abstract The shape of the radial distribution of blue straggler stars (BSS), when normalized to a reference population of horizontal branch (HB) stars, has been found to be a powerful indicator of the dynamical evolution reached by a globular cluster (GC).
Pasquato +5 more
openaire +3 more sources

