Results 71 to 80 of about 837,700 (191)

Calibration of the [C/N] and [Y/Mg] chemical clocks with asteroseismic ages from the TESS space mission

Astronomy & Astrophysics
Context. Stellar ages are typically very difficult to estimate for field stars. New empirical methods, based on abundance ratios of chemical elements, are emerging and need to be calibrated. Aims.
Pakštienė E., Tautvaišienė G., Bagdonas V., Kjeldsen H., Winther M. L., Drazdauskas A., Viscasillas Vázquez C., Chorniy Y., Mikolaitis Š., Minkevičiūte R., Stonkutė E.   +10 more
doaj   +1 more source

The APO-K2 Catalog. II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way

The Astronomical Journal
We present stellar age determinations for 4661 red giant branch stars in the APO-K2 catalog, derived using mass estimates from K2 asteroseismology from the K2 Galactic Archaeology Program and elemental abundances from the Apache Point Galactic Evolution ...
Jack T. Warfield, Joel C. Zinn, Jessica Schonhut-Stasik, James W. Johnson, Marc H. Pinsonneault, Jennifer A. Johnson, Dennis Stello, Rachael L. Beaton, Yvonne Elsworth, Rafael A. García, Savita Mathur, Benoît Mosser, Aldo Serenelli, Jamie Tayar   +13 more
doaj   +1 more source

A New Asteroseismic Kepler Benchmark Constrains the Onset of Weakened Magnetic Braking in Mature Sun-like Stars

The Astrophysical Journal
Stellar spin down is a critical yet poorly understood component of stellar evolution. In particular, results from the Kepler Mission imply that mature age, solar-type stars have inefficient magnetic braking, resulting in a stalled spin-down rate. However,
Vanshree Bhalotia, Daniel Huber, Jennifer L. van Saders, Travis S. Metcalfe, Keivan G. Stassun, Timothy R. White, Víctor Aguirre Børsen-Koch, Warrick H. Ball, Sarbani Basu, Aldo M. Serenelli, Erica Sawczynec, Joyce A. Guzik, Andrew W. Howard, Howard Isaacson   +13 more
doaj   +1 more source

The Evolution of Flare Activity with Stellar Age

The Astrophysical Journal, 2019
Abstract Using a recent census of flare stars from the Kepler survey, we have explored how flare activity evolves across stellar main-sequence lifetimes. We utilize a sample of 347 stars with robust flare activity detections and which have rotation periods measured via starspot modulations in their Kepler light curves.
James R. A. Davenport, Kevin R. Covey, Riley W. Clarke, Austin C. Boeck, Jonathan Cornet, Suzanne L. Hawley   +5 more
openaire   +2 more sources

Final report on the STELLAR Delphi study: Future directions for TEL and TEL research: areas of tension, core research areas and grand challenge problems

, 2012
In this report on the STELLAR Delphi study, we present the results of the final global survey, that is the 4th STELLAR Delphi round, and illustrate the elaboration and dissemination of these results (5th STELLAR Delphi round).
Spada, Hans, Plesch, Christine, Wiedmann, Michael   +2 more
core   +2 more sources

Ages and Age Spreads in Young Stellar Clusters

, 2017
I review progress towards understanding the time-scales of star and cluster formation and of the absolute ages of young stars. I focus in particular on the areas in which Francesco Palla made highly significant contributions - interpretation of the Hertzsprung-Russell diagrams of young clusters and the role of photospheric lithium as an age diagnostic.
openaire   +2 more sources

The Relationship between Accretion Disc Age and Stellar Age and its Consequences for Proto-Stellar Discs

, 2011
11 pages, 10 figures, 2 ...
Jones, Michael, Pringle, Jim, Alexander, Richard   +2 more
openaire   +2 more sources

Finding Ages for Old Stellar Populations [PDF]

Symposium - International Astronomical Union, 1996
We are far from being able to populate a histogram of star formation versus time for an elliptical galaxy based solely on observations of its spectrum, but the path toward such a dream is becoming more clear. Still, we are denied the easiest paths, and most of what I have been thinking about in the last six months are the obstacles rather than the ...
openaire   +1 more source

Intermediate report on the Delphi study: Findings from the 2nd and the 3rd STELLAR Delphi rounds: Areas of tension and core research areas

, 2011
This intermediate report on the STELLAR Delphi study closes the gap between the first deliverable on the Delphi study D1.3 (Spada et al. 2010) which was published in July 2010 and the second and final deliverable D1.6 which is planned for January 2012 ...
Spada, Hans, Plesch, Christine, Kaendler, Celia   +2 more
core   +2 more sources

Kinematic Ages of the Tucana–Horologium, Columba, and Carina Associations

The Astrophysical Journal
The traceback method allows the computation of the kinematic age of nearby young associations from astrometric and kinematic data alone, circumventing the need for stellar evolution models.
Dominic Couture, Jonathan Gagné, René Doyon   +2 more
doaj   +1 more source