Results 1 to 10 of about 584,997 (333)

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

Chemical Composition of RM_1-390 - Large Magellanic Cloud Red Supergiant [PDF]

Journal of Astronomy and Space Sciences, 2017
A high resolution spectroscopic observation of the red supergiant star RM_1-390 in the Large Magellanic Cloud was made from a 3.6 m telescope at the European Southern Observatory. Spectral resolving power was R=20,000, with a signal-to-noise ratio S/N >
Alexander V. Yushchenko, Yeuncheol Jeong, Vira F. Gopka, Svetlana V. Vasil’eva, Sergey M. Andrievsky, Volodymyr O. Yushchenko   +5 more
doaj   +1 more source

Nucleosynthesis, Mixing Processes, and Gas Pollution from AGB Stars

Universe, 2022
We discuss the evolution of stars through the asymptotic giant branch, focusing on the physical mechanisms potentially able to alter the surface chemical composition and on how changes in the chemistry of the external regions affect the physical ...
Paolo Ventura, Flavia Dell’Agli, Marco Tailo, Marco Castellani, Ester Marini, Silvia Tosi, Marcella Di Criscienzo   +6 more
doaj   +1 more source

Structure formation cosmic rays: Identifying observational constraints [PDF]

Serbian Astronomical Journal, 2005
Shocks that arise from baryonic in-fall and merger events during the structure formation are believed to be a source of cosmic rays. These "structure formation cosmic rays" (SFCRs) would essentially be primordial in composition, namely, mostly made of ...
Prodanović T., Fields B.D.
doaj   +1 more source

Magellanic Clouds Cepheids: Thorium Abundances [PDF]

Journal of Astronomy and Space Sciences, 2018
The analysis of the high-resolution spectra of 31 Magellanic Clouds Cepheid variables enabled the identification of thorium lines. The abundances of thorium were found with spectrum synthesis method. The calculated thorium abundances exhibit correlations
Yeuncheol Jeong, Alexander V. Yushchenko, Vira F. Gopka, Volodymyr O. Yushchenko, Valery V. Kovtyukh, Svetlana V. Vasil’eva   +5 more
doaj   +1 more source

The Record-Warm Barents Sea and 0-Group Fish Response to Abnormal Conditions

Frontiers in Marine Science, 2020
The Barents Sea is a nursery area for many commercially and ecologically important fish stocks, and this whole region is presently subject to rapid climatic change from a cold period in the 1980s to a record warm period in the latest decade, with a peak ...
Elena Eriksen, Espen Bagøien, Espen Strand, Raul Primicerio, Raul Primicerio, Tatiana Prokhorova, Alexander Trofimov, Irina Prokopchuk   +7 more
doaj   +1 more source

Theoretical Predictions of Surface Light Element Abundances in Protostellar and Pre-Main Sequence Phase

Frontiers in Astronomy and Space Sciences, 2021
Theoretical prediction of surface stellar abundances of light elements–lithium, beryllium, and boron–represents one of the most interesting open problems in astrophysics.
E. Tognelli, E. Tognelli, S. Degl’Innocenti, S. Degl’Innocenti, P. G. Prada Moroni, P. G. Prada Moroni, L. Lamia, L. Lamia, L. Lamia, R. G. Pizzone, A. Tumino, A. Tumino, C. Spitaleri, C. Spitaleri, A. Chiavassa   +14 more
doaj   +1 more source

Neon and Sulfur Abundances of Planetary Nebulae in the Magellanic Clouds [PDF]

, 2007
The chemical abundances of neon and sulfur for 25 planetary nebulae (PNe) in the Magellanic Clouds are presented. These abundances have been derived using mainly infrared data from the Spitzer Space Telescope.
Aller L. H., de Graauw T., Feldman U., Fluks M. A., Grevesse N., J. Bernard‐Salas, J. R. Houck, Monk D. J., P. W. Morris, Pena M., S. Gutenkunst, S. R. Pottasch, Zijlstra A. A.   +12 more
core   +4 more sources

Close Binaries and the Abundance Discrepancy Problem in Planetary Nebulae

Galaxies, 2018
Motivated by the recent establishment of a connection between central star binarity and extreme abundance discrepancies in planetary nebulae, we have carried out a spectroscopic survey targeting planetary nebula with binary central stars and previously ...
R. Wesson, D. Jones, J. García-Rojas, H. M. J. Boffin, R. L. M. Corradi   +4 more
doaj   +1 more source

Indirect Measurements of n- and p-Induced Reactions of Astrophysical Interest on Oxygen Isotopes

Frontiers in Astronomy and Space Sciences, 2020
Observations of abundances and isotopic ratio determinations in stars yield powerful constraints on stellar models. In particular, the oxygen isotopic ratios are of particular interest because they are affected not only by nucleosynthesis but also by ...
M. L. Sergi, M. L. Sergi, G. L. Guardo, G. L. Guardo, M. La Cognata, M. Gulino, M. Gulino, J. Mrazek, S. Palmerini, S. Palmerini, C. Spitaleri, C. Spitaleri, M. Wiescher   +12 more
doaj   +1 more source