Results 71 to 80 of about 876,778 (355)

High-precision abundances of elements in solar twin stars - Trends with stellar age and elemental condensation temperature [PDF]

, 2015
Context. High-precision determinations of abundances of elements in the atmospheres of the Sun and solar twin stars indicate that the Sun has an unusually low ratio between refractory and volatile elements.
P. Nissen
semanticscholar   +1 more source

The Interaction Between Accretion from the Interstellar Medium and Accretion from the Evolved Binary Component in Barium Stars [PDF]

Journal of Astronomy and Space Sciences, 2018
The reanalysis of the previously published abundance pattern of mild barium star HD202109 (ζ Cyg) and the chemical compositions of 129 thin disk barium stars facilitated the search for possible correlations of different stellar parameters with second ...
Yeuncheol Jeong, Alexander V. Yushchenko, Dmytry N. Doikov   +2 more
doaj   +1 more source

ON THE CARBON-TO-OXYGEN RATIO MEASUREMENT IN NEARBY SUN-LIKE STARS: IMPLICATIONS FOR PLANET FORMATION AND THE DETERMINATION OF STELLAR ABUNDANCES [PDF]

, 2012
Recent high-resolution spectroscopic analysis of nearby FGK stars suggests that a high C/O ratio of greater than 0.8, or even 1.0, is relatively common. Two published catalogs find C/O > 0.8 in 25%–30% of systems, and C/O > 1.0 in ∼6%–10%.
J. Fortney
semanticscholar   +1 more source

The abundance of helium and stellar pulsation

Astronomical & Astrophysical Transactions, 1998
Radial gradient of relative amplitude of the light variation FV for galactic classical Cepheids is found. The gradient has different signs for two cases: P > 8d and P < 8d. For P > 8d the gradient is negative. This gradient is caused by gradient of helium content in the primordial clouds, where Cepheids were born.
openaire   +4 more sources

Stellar Abundance Observations

, 1998
10 pages, 6 figures To appear in the Proceedings of the Second Oak Ridge Symposium on Atomic & Nuclear ...
Cowan, John J, Sneden, Christopher, Truran, James W, Burris, Debra L   +3 more
openaire   +2 more sources

The unpredictably eruptive dynamics of spruce budworm populations in eastern Canada

Population Ecology, EarlyView.
We examine historical population data for spruce budworm from several locations through the period 1930–1997, and use density‐dependent recruitment curves to test whether the pattern of population growth over time is more consistent with Royama's (1984; Ecological Monographs 54:429–462) linear R(t) model of harmonic oscillation at Green River New ...
Barry J. Cooke, Jacques Régnière
wiley   +1 more source

Observable Signatures of Planet Accretion in Red Giant Stars I: Rapid Rotation and Light Element Replenishment

, 2012
The orbital angular momentum of a close-orbiting giant planet can be sufficiently large that, if transferred to the envelope of the host star during the red giant branch (RGB) evolution, it can spin-up the star's rotation to unusually large speeds.
Alexander, Balachandran, Bard, Bard, Bizyaev, Blackwell, Blackwell, Blackwell, Blackwell, Blackwell, Blaise, Boothroyd, Busso, Butler, Böhm-Vitense, Carlberg, Carlberg, Carlberg, Carlberg, Carney, Castelli, Castilho, Chanamé, Charbonnel, Charbonnel, da Silva, Davis, de Medeiros, de Medeiros, Denissenkov, Denissenkov, Drake, Duquennoy, Eggleton, Frink, Fuhr, Fulbright, Ghezzi, Glebocki, Gratton, Griffin, Griffin, Hinkle, Houdashelt, Høg, Joleen K. Carlberg, Katia Cunha, Kumar, Kumar, Kurucz, Kurucz, Kurucz, Kurucz, Kurucz, Lodders, Majewski, Mandell, Massarotti, Mitchell, Mousis, Nordhaus, Palmerini, Paxton, Pilachowski, Piskunov, Raassen, Rabl, Raghavan, Reddy, Reddy, Ruchti, Sackmann, Sato, Schlegel, Shetrone, Smith, Smith, Sneden, Steven R. Majewski, Strassmeier, Uesugi, Verne V. Smith, Vogt, Wasserburg   +83 more
core   +1 more source

A Systematic NLTE Study of Very Metal-poor Stars with Metallicity down to −4.3 dex. I. Global Stellar Parameters Based on High-resolution Spectra

The Astrophysical Journal
Very metal-poor (VMP) stars provide a record of the chemical composition and dynamics of the early Galaxy. Based on the high-resolution and high signal-to-noise ratio spectra from the Subaru Telescope for 103 VMP stars, in this series of papers we ...
Jianrong Shi, Gang Zhao, Shuai Liu, Zeming Zhou, Haining Li, Hongliang Yan, Sofya Alexeeva, Huawei Zhang, Wako Aoki, Tadafumi Matsuno, Jingkun Zhao, Huiling Chen, Yufu Shen   +12 more
doaj   +1 more source

Network topology drives population temporal variability in experimental habitat networks

Population Ecology, EarlyView.
Habitat patches connected by dispersal pathways form habitat networks. We explored how network topology affects population outcomes in laboratory experiments using a model species (Daphnia carinata). Central habitat nodes in complex lattice networks exhibited lower temporal variability in population sizes, suggesting they support more stable ...
Yiwen Xu, J. Angus Webb, William D. Bovill, Elise L. King   +3 more
wiley   +1 more source

Chemical consequences of low star formation rates: stochastically sampling the IMF

, 2008
When estimating the abundances which result from a given star formation event, it is customary to treat the IMF as a series of weight factors to be applied to the stellar yields, as a function of mass, implicitly assuming one is dealing with an infinite ...
Anders, Asplund, Carigi, Carigi, Carigi, Carigi, Carigi, Cerviño, Cerviño, Cerviño, Cescutti, Fenner, Geisler, Gilmore, Goodwin, Greggio, Greggio, Hernandez, Hirschi, Ikuta, Kniazev, Koeppen, Kroupa, Kroupa, L. Carigi, Lanfranchi, Lanfranchi, Maeder, Maeder, Maeder, Marcolini, Marigo, Marigo, Massey, Matteucci, McWilliam, Meynet, Pagel, Portinari, Sbordone, Shetrone, Shetrone, Thielemann, Tonry, van Zee, Venn, Weidner, Weidner, Woosley, X. Hernandez   +49 more
core   +1 more source