Results 31 to 40 of about 5,356 (321)
Blue Straggler Stars in Galactic Open Clusters and the effect of field star contamination [PDF]
, 2008 We investigate the distribution of Blue Straggler stars in the field of three open star clusters. The main purpose is to highlight the crucial role played by general Galactic disk fore-/back-ground field stars, which are often located in the same region ...
A. Moitinho +27 more
core +5 more sources
Blue stragglers in open clusters [PDF]
Astronomy & Astrophysics, 2001 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
openaire +1 more source
M67 Blue Stragglers with High-resolution Infrared Spectroscopy
The Astronomical Journal, 2023 We report on the first detailed infrared chemical analysis of five binary members (S277, S997, S975, S1031, and S1195) in the open cluster M67 (NGC 2682).
K. E. Brady +7 more
doaj +1 more source
The Astrophysical Journal, 2023 We present the first far-UV (FUV) imaging results of the intermediate-age Galactic open cluster NGC 2818 that has a planetary nebula (PN) within the field using images taken from the Ultra Violet Imaging Telescope (UVIT) aboard AstroSat.
Sharmila Rani +3 more
doaj +1 more source
On the Origin of the Split Main Sequences of the Young Massive Cluster NGC 1856
The Astrophysical Journal, 2023 The detection of split main sequences (MSs) associated with young clusters (≲600 Myr) has attracted a lot of attention. A prevailing scenario is that a bimodality of stellar rotation distribution drives the bifurcation of the MS. Nevertheless, the origin
Li Wang +4 more
doaj +1 more source
The lithium abundance of M67 blue stragglers - A constraint on the blue straggler phenomenon
The Astrophysical Journal, 1991 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
openaire +1 more source
A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster
The Astrophysical Journal Letters, 2023 We report metallicities for three ∼Gyr-old stars in the Milky Way nuclear star cluster (NSC) using high-resolution near-infrared spectroscopy. We derive effective temperatures from a calibration with Sc line strength, which yields results in good ...
B. Thorsbro +8 more
doaj +1 more source
Variable Blue Straggler Stars in the Open Cluster NGC 6819 Observed in the Kepler “Superstamp” Field
The Astronomical Journal, 2023 NGC 6819 is an open cluster of age 2.4 Gyr that was in the NASA Kepler spacecraft’s field of view from 2009 to 2013. The central part of the cluster was observed in a 200 × 200 pixel “superstamp” during these four years in 30 minute cadence photometry ...
Joyce A. Guzik +6 more
doaj +1 more source
The origins of blue stragglers and binarity in globular clusters [PDF]
Monthly Notices of the Royal Astronomical Society, 2012 (abridged) We use newly available empirical binary fractions for globular clusters to carry out a direct test of the binary evolution hypothesis, and of collisional channels that involve binary stars. More specifically, using the previously reported correlation between blue straggler numbers and core mass as a benchmark, we test for correlations with ...
Leigh, N. +5 more
openaire +3 more sources
, 2014 Several possible formation pathways for blue straggler stars have been developed recently, but no one pathway has yet been observationally confirmed for a specific blue straggler.
Geller, Aaron M. +5 more
core +1 more source