Results 81 to 90 of about 4,407 (194)

WIYN Open Cluster Study. XC. Radial-velocity Measurements and Spectroscopic Binary Orbits in the Open Cluster NGC 2506

open access: yesThe Astronomical Journal
NGC 2506 is a rich, intermediate-age (2.0 Gyr), metal-poor ([Fe/H] ∼ −0.2) open cluster. This work presents the results of 12,157 spectroscopic radial-velocity measurements of 2442 stars in the NGC 2506 field obtained over 41 yr, made as part of the WIYN
Evan Linck   +2 more
doaj   +1 more source

Discovery of a Barium Blue Straggler Star in M67 and “Sighting” of Its White Dwarf Companion

open access: yesThe Astrophysical Journal Letters
We report the discovery of a barium blue straggler star (BSS) in M67, exhibiting enhancements in slow neutron-capture ( s -)process elements. Spectroscopic analysis of two BSSs (WOCS 9005 & WOCS 1020) and four stars located near the main-sequence turn ...
Harshit Pal   +3 more
doaj   +1 more source

New parameters for star-cluster dynamics: Observational results

open access: yesAstronomy & Astrophysics
We recently used a large set of Monte Carlo simulations of globular clusters (GCs) to define new, fully empirical parameters (named A51, P51, and S2.5) able to trace the internal dynamical evolution of dense stellar systems.
Lanzoni B., Ferraro F. R., Vesperini E.
doaj   +1 more source

A proper motion study of the globular cluster M55

open access: yes, 2011
We have derived the absolute proper motion (PM) of the globular cluster M55 using a large set of CCD images collected with the du Pont telescope between 1997 and 2008. We find (PM_RA*cos(DEC), PM_DEC) = (-3.31 +/- 0.10, -9.14 +/- 0.15) mas/yr relative to
Anderson   +25 more
core   +1 more source

Stellar Encounters with Multiple Star Systems and the Blue Straggler Problem

open access: yes, 2010
We present a technique to identify the most probable dynamical formation scenario for an observed binary or triple system containing one or more merger products or, alternatively, to rule out the possibility of a dynamical origin. Our method relies on an
Leigh, Nathan, Sills, Alison
core   +1 more source

A Thorough Exploration of the Metal-rich Massive Open Cluster NGC 6253: Focusing on Membership, Binaries, Stragglers, and Mass Function

open access: yesThe Astrophysical Journal
This study provides an in-depth analysis of the ancient open galactic cluster NGC 6253, characterized by the presence of both blue and yellow straggler stars.
Huanbin Chi, Feng Wang
doaj   +1 more source

Trends in the decapod crustacean community at the southernmost estuary of the Atlantic coast of Europe. [PDF]

open access: yesSci Rep, 2023
González-Ortegón E   +4 more
europepmc   +1 more source

Mergers of close primordial binaries

open access: yes, 2005
We study the production of main sequence mergers of tidally-synchronized primordial short-period binaries. The principal ingredients of our calculation are the angular momentum loss rates inferred from the spindown of open cluster stars and the ...
Ahumada J.   +18 more
core   +1 more source

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