Results 31 to 40 of about 3,286 (161)

ISO Results on Star Formation and Early Stellar Evolution [PDF]

Highlights of Astronomy, 1998
With all its instruments, ISO is sensitive to temperatures in the range ~ 30 – 2000 K. This range is particularly adapted to studies of dense interstellar matter (gas and dust) in cold clouds, and to material associated with very early stages of stellar evolution: circumstellar matter around low-mass stars (disks, envelopes), outflows generated by them
Thierry Montmerle, Lennart Nordh
openaire   +1 more source

Stellar evolution with rotation [PDF]

Astronomy & Astrophysics, 2002
We calculate a grid of star models with and without the effects of axial rotation for stars in the mass range between 2 and 60 M$_{\odot}$ for the metallicity $Z = 10^{-5}$. Star models with initial masses superior or equal to 9 M$_\odot$ were computed up to the end of the carbon--burning phase.
Meynet, Georges, Maeder, Andre
openaire   +2 more sources

Impact of Population III homogeneous stellar evolution on early cosmic reionisation

Astronomy & Astrophysics, 2022
Context. Population III (Pop III) stars may be fast rotating. An expected consequence of fast rotation is strong internal mixing that deeply affects their evolutionary tracks in the Hertzsprung-Russell diagram and hence their ionising power. Aims. We investigate the impact on the ionising power of Pop III stars in an extreme case of internal mixing ...
Y. Sibony, B. Liu, C. Simmonds, G. Meynet, V. Bromm   +4 more
openaire   +2 more sources

Stellar Evolution and Convection in 3D Hydrodynamic Simulations of a Complete Burning Phase

Galaxies
Our understanding of stellar evolution and nucleosynthesis is limited by the uncertainties coming from the complex multi-dimensional processes in stellar interiors, such as convection and nuclear burning. Three-dimensional stellar models can improve this
Federico Rizzuti, Raphael Hirschi, Vishnu Varma, William David Arnett, Cyril Georgy, Casey Meakin, Miroslav Mocák, Alexander StJ. Murphy, Thomas Rauscher   +8 more
doaj   +1 more source

Analysis of DQZ White Dwarf Evolution through Procyon

The Astrophysical Journal
Procyon is a great system to probe stellar evolution of noninteracting binaries. We present an extensive grid of Modules for Experiments in Stellar Astrophysics evolutionary tracks to constrain the evolution of Procyon A and B. We systematically vary the
Momin Y. Khan, Barbara G. Castanheira
doaj   +1 more source

Evolution of Stellar Activity in Early Post-Main-Sequence Phases [PDF]

International Astronomical Union Colloquium, 1993
We present preliminary observational evidences on the variation of the activity level in late type stars, during the evolutionary phases on the main sequence and beyond. We have selected a sample of 51 stars (Fig. 1), lying mostly along evolutionary tracks between 1.3 and 1.7 solar masses, which have been observed in soft X-rays with the Einstein ...
A. Maggio, S. Sciortino, L. Bianchi, F.R. Harnden, R. Rosner   +4 more
openaire   +1 more source

A Stellar Bar Hidden in an Extreme Gas-rich Disk Galaxy at z = 4.055

The Astrophysical Journal Letters
The classical picture for the formation of stellar bars—key dynamical drivers of the evolution of galaxies—is through secular evolution of instability in gas-poor, stellar-dominated disks. The detection with the James Webb Space Telescope of stellar bars
Leindert A. Boogaard, Luca Costantin, Thor Tepper-García, Joss Bland-Hawthorn, Jacqueline A. Hodge, Cheng-Lin Liao, Mahmoud Hamed, Luis Colina, Fabian Walter, Oscar Agertz, Arjan Bik, Alejandro Crespo Gómez, Emanuele Daddi, Georgios E. Magdis, Pablo G. Pérez-González, Hannah Übler, Axel Weiss   +16 more
doaj   +1 more source

Early phases in the stellar and substellar formation and evolution [PDF]

Astronomy & Astrophysics, 2018
Aims. The early evolutionary stage of brown dwarfs (BDs) is not very well characterized, especially during the embedded phase. Our goal is to gain insight into the dominant formation mechanism of very low-mass objects and BDs. Methods. We have conducted deep observations at 870 μm obtained with the LABOCA bolometer at the APEX telescope in order to ...
D. Barrado, I. de Gregorio Monsalvo, N. Huélamo, M. Morales-Calderón, A. Bayo, A. Palau, M. T. Ruiz, P. Rivière-Marichalar, H. Bouy, Ó. Morata, J. R. Stauffer, C. Eiroa, A. Noriega-Crespo   +12 more
openaire   +4 more sources

TESS Hunt for Young and Maturing Exoplanets (THYME). XIV. A Comoving-based Age Constraint for KELT-20

The Astronomical Journal
Young stellar moving groups offer unique opportunities to investigate the early evolution of stellar and planetary systems. In continuation of an ongoing effort to age-date compelling planetary systems, we provide an in-depth age analysis of KELT-20—a ...
Adam Distler, Melinda Soares-Furtado, Andrew W. Mann, Adam L. Kraus, Jonathan Gagné, Juliette Becker, Ritvik Sai Narayan, Max Clark, Andrew Vanderburg, Joseph E. Rodriguez, Laura K. Rogers, Ronan Kerr   +11 more
doaj   +1 more source

Early-type Galaxies on the Star Formation Main Sequence: Internal Star Formation Geometries Revealed with MaNGA and Their Environmental Origin

The Astrophysical Journal
Star-forming galaxies on the main sequence (MS) are often regarded as a uniform population characterized by similar global star formation properties. However, there exists a diversity in galaxy morphologies at a fixed stellar mass and star formation rate.
Shuhei Koyama, Yusei Koyama, Takuji Yamashita, Masahiro Konishi, Kosuke Kushibiki, Kentaro Motohara   +5 more
doaj   +1 more source