Results 1 to 10 of about 200,990 (159)

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

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

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

Chemical Composition of RR Lyn – an Eclipsing Binary System with Am and λ Boo Type Components [PDF]

Journal of Astronomy and Space Sciences, 2017
High-resolution spectroscopic observations of the eclipsing binary system RR Lyn were made using the 1.8 m telescope at the Bohuynsan Optical Astronomical Observatory in Korea.
Yeuncheol Jeong, Alexander V. Yushchenko, Dmytry N. Doikov, Vira F. Gopka, Volodymyr O. Yushchenko   +4 more
doaj   +1 more source

Calcareous Nannofossils Biostratigraphy of Late Cretaceous–Paleocene Successions from Northern Jordan and Their Implications for Basin Analysis

Geosciences, 2023
Local geological and tectonic processes have been pivotal in shaping the diverse sedimentation patterns observed in Jordan, forming sub-basins characterized by elevated organic matter content (TOC). This study aims to characterize the Maastrichtian basin,
Albesher Hussein, Osama M. Al-Tarawneh, Mohammad Alqudah   +2 more
doaj   +1 more source

Light Elements in the Universe

Frontiers in Astronomy and Space Sciences, 2021
Due to their production sites, as well as to how they are processed and destroyed in stars, the light elements are excellent tools to investigate a number of crucial issues in modern astrophysics: from stellar structure and non-standard processes at work
Sofia Randich, Laura Magrini
doaj   +1 more source

Integral Field Spectroscopy of Planetary Nebulae with MUSE

Galaxies, 2020
The Multi-Unit Spectroscopic Explorer (MUSE) is a large integral field unit mounted on the ESO Very Large Telescope. Its spatial (60 arcsecond field) and wavelength (4800–9300Å) coverage is well suited to detailed imaging spectroscopy of extended ...
Jeremy R. Walsh, Ana Monreal-Ibero
doaj   +1 more source