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Related papers: A method to estimate stellar ages from kinematical…

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The orbit distribution of young stars in the Galactic disk is highly structured, from well-defined clusters to streams of stars that may be widely dispersed across the sky, but are compact in orbital action-angle space. The age distribution…

Astrophysics of Galaxies · Physics 2023-11-20 Verena Fürnkranz , Hans-Walter Rix , Johanna Coronado , Rhys Seeburger

We explore the connections between stellar age, chemistry, and kinematics across a Galactocentric distance of $7.5 < R\,(\mathrm{kpc}) < 9.0$, using a sample of $\sim 12\,000$ intermediate-mass (FGK) turnoff stars observed with the RAdial…

Accurate stellar ages are essential for our understanding of the star formation history of the Milky Way, Galactic chemical evolution, and to constrain exoplanet formation models. Gyrochronology, a relationship between stellar rotation and…

Solar and Stellar Astrophysics · Physics 2022-05-11 Tomomi Otani , Ted von Hippel , Derek Buzasi , T. D. Oswalt , Alexander Stone-Martinez , Patrice Majewski

Determining the sequence of events in the formation of stars and planetary systems and their time-scales is essential for understanding those processes, yet establishing ages is fundamentally difficult because we lack direct indicators. In…

Solar and Stellar Astrophysics · Physics 2015-06-18 David R. Soderblom , Lynne A. Hillenbrand , Rob D. Jeffries , Eric E. Mamajek , Tim Naylor

We determine detailed elemental abundances in stars belonging to the so-called Group 1 of the Geneva-Copenhagen survey (GCS) and compare the chemical composition with the Galactic thin- and thick-disc stars, with the GCS Group 2 and Group 3…

Solar and Stellar Astrophysics · Physics 2015-06-23 R. Ženovienė , G. Tautvaišienė , B. Nordström , E. Stonkutė , G. Barisevičius

With the advent of dedicated photometric space missions, the ability to rapidly process huge catalogues of stars has become paramount. Bellinger and Angelou et al. (2016) recently introduced a new method based on machine learning for…

Solar and Stellar Astrophysics · Physics 2017-11-08 Earl P. Bellinger , George C. Angelou , Saskia Hekker , Sarbani Basu , Warrick H. Ball , Elisabeth Guggenberger

Age is the most difficult fundamental stellar parameter to infer for isolated stars. While isochrone-based ages are in general imprecise for both main sequence dwarfs and red giants, precise isochrone-based ages can be obtained for stars on…

Solar and Stellar Astrophysics · Physics 2024-07-29 David M. Nataf , Kevin C. Schlaufman , Henrique Reggiani , Isabel Hahn

We present our new, fully-automated method to detect and measure the ages of star clusters in nearby galaxies, where individual stars can be resolved. The method relies purely on statistical analysis of observations and Monte-Carlo…

We present recent progress on quantitative estimation of stellar ages using ind icators such as theoretical evolutionary tracks, rotation, rotation-driven chrom ospheric and coronal activity, and lithium depletion. Our focus is on roughly…

We combine photometric metallicities with astrometry from Gaia DR3 to examine the chemodynamic structure of ~250,000 K dwarfs in the Solar Neighborhood (SN). In kinematics, we observe ridges/clumps of "kinematic groups", like studies of…

Astrophysics of Galaxies · Physics 2023-02-15 Ilija Medan , Sébastien Lépine

Stellar ages are key for determining the formation history of the Milky Way, but are difficult to measure precisely. Furthermore, methods that use chemical abundances to infer ages may entangle the intrinsic evolution of stars with the…

Astrophysics of Galaxies · Physics 2023-05-26 Jeff Shen , Joshua S. Speagle , J. Ted Mackereth , Yuan-Sen Ting , Jo Bovy

We aim to develop a model-driven deep learning approach to age determination, by training neural networks on stellar evolutionary grids. Contrary to the usual data-driven deep learning approach of using prior age estimates as training data,…

Astrophysics of Galaxies · Physics 2026-04-15 T. Boin , L. Casamiquela , M. Haywood , P. Di Matteo , Y. Lebreton , M. Uddin , D. R. Reese

Ages, metallicities, space velocities, and Galactic orbits of stars in the Solar neighbourhood are fundamental observational constraints on models of galactic disk evolution. We aim to consolidate the calibrations of uvby photometry into…

Astrophysics · Physics 2009-11-13 J. Holmberg , B. Nordstrom , J. Andersen

We present a catalog of ~100,000 periodic variable stars in TESS FFI data among members of widely distributed moving groups identified with Gaia in the previous papers in the series. By combining the periods from our catalog attributable to…

Solar and Stellar Astrophysics · Physics 2022-09-21 Marina Kounkel , Keivan G. Stassun , Luke G. Bouma , Kevin Covey , Lynne A. Hillenbrand , Jason Lee Curtis

We have observed and spatially resolved a set of seven A-type stars in the nearby Ursa Major moving group with the Classic, CLIMB, and PAVO beam combiners on the CHARA Array. At least four of these stars have large rotational velocities ($v…

Reliable stellar age estimates are fundamental for testing several problems in modern astrophysics, in particular since they set the time scales of Galactic dynamical and chemical evolution. In this study, we determine ages using only Gaia…

Astrophysics of Galaxies · Physics 2024-12-18 L. Casamiquela , D. R. Reese , Y. Lebreton , M. Haywood , P. Di Matteo , F. Anders , R. Jash , D. Katz , V. Cerqui , T. Boin , G. Kordopatis

We present a statistical approach for estimating the age of Globular Clusters by measurement of the likelihood between the observed cluster sequences in the Colour--Magnitude Diagram and the synthetic cluster sequences computed from stellar…

Astrophysics · Physics 2009-11-07 Miriam Rengel , Gustavo Bruzual

The stellar kinematics of the Galactic disk are main factors for constraining disk formation and evolution processes in the Milky Way (MW) Galaxy. In this paper we investigate a statistical relation between stellar Mass, Age and Velocity…

Astrophysics of Galaxies · Physics 2023-03-15 Hossein Fatheddin , Sedighe Sajadian

We investigated the age-metallicity relation using a sample of 5691 F and G type dwarfs from RAVE DR3 by applying several constraints: i) We selected stars with surface gravities log g < 3.8 and effective temperatures in the…

Astrophysics of Galaxies · Physics 2015-06-16 S. Duran , S. Ak , S. Bilir , S. Karaali , T. Ak , Z. F. Bostanci , B. Coskunoglu

We present Gemini/GNIRS cross-dispersed near-infrared spectra of 12 nearby early-type galaxies, with the aim of testing commonly used stellar population synthesis models. We select a subset of galaxies from the atlas/ sample which span a…

Astrophysics of Galaxies · Physics 2017-12-06 C. M. Baldwin , R. M. McDermid , H. Kuntschner , C. Maraston , C. Conroy