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Related papers: Chromospherically young, kinematically old stars

200 papers

The cooling theory of neutron stars is corroborated by its comparison with observations of thermally emitting isolated neutron stars and accreting neutron stars in binary systems. An important ingredient for such an analysis is the age of…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Ramandeep Gill , Jeremy S. Heyl

Observations of Young Star Cluster ({\bf YSC}) systems in interacting galaxies are reviewed with particular emphasis on their Luminosity Functions ({\bf LF}) and colour distributions. A few spectroscopic abundance measurements are…

Astrophysics · Physics 2007-05-23 Uta Fritze-v. Alvensleben

Asteroseismology, as a tool to use the indirect information contained in stellar oscillations to probe the stellar interiors, is an active field of research presently. Stellar age, as a fundamental property of star apart from its mass, is…

Astrophysics · Physics 2009-11-13 Y. K. Tang , S. L. Bi , N. Gai

Many characteristics of dwarf carbon stars are broadly consistent with a binary origin, including mass transfer from an evolved companion. While the population overall appears to have old-disc or halo kinematics, roughly 2$\,$per cent of…

Solar and Stellar Astrophysics · Physics 2021-08-04 L. J. Whitehouse , J. Farihi , I. D. Howarth , S. Mancino , N. Walters , A. Swan , T. G. Wilson , J. Guo

We provide a status report on the determination of stellar ages from asteroseismology for stars of various masses and evolutionary stages. The ability to deduce the ages of stars with a relative precision of typically 10 to 20% is a unique…

Solar and Stellar Astrophysics · Physics 2015-08-06 Conny Aerts

Orbits of 44 close and fast visual binaries are computed using the latest speckle observations; 23 orbits are determined for the first time, the rest are revisions, some quite substantial. Six combined orbits use radial velocities. The…

Solar and Stellar Astrophysics · Physics 2017-08-30 Andrei Tokovinin

Stellar chromospheric activity serves as a valuable proxy for estimating stellar ages, though its applicable range and accurate functional form are still debated. In this study, utilizing the LAMOST spectra we compiled a catalog of open…

Solar and Stellar Astrophysics · Physics 2026-01-27 Henggeng Han , Song Wang , Xue Li , Chuanjie Zheng , Jiahui Wang , Jifeng Liu

Long-term photometric measurements in a sample of ultrashort-period (P~0.5 days or less) single and binary stars of different interior structures are analysed. A loose correlation exists between the rotational rate and cycle lengths of…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. Vida , L. Kriskovics , K. Oláh

Age is an important characteristic of a planetary system, but also one that is difficult to determine. Assuming that the host star and the planets are formed at the same time, the challenge is to determine the stellar age. Asteroseismology…

Solar and Stellar Astrophysics · Physics 2018-12-05 Joergen Christensen-Dalsgaard , Victor Silva Aguirre

Chromospheric activity is widely used as an age indicator for solar-type stars based on the early evidence that there is a smooth evolution from young and active to old and inactive stars. We analysed chromospheric activity in five…

Solar and Stellar Astrophysics · Physics 2010-05-07 G. Pace , J. Melendez , L. Pasquini , G. Carraro , J. Danziger , P. Francois , F. Matteucci , N. C. Santos

Aims: We present a compilation of spectroscopic data from a survey of 144 chromospherically active young stars in the solar neighborhood which may be used to investigate different aspects of the formation and evolution of the solar…

A calibration of H-alpha as both a chromospheric diagnostic and an age indicator is presented, complementing the works previously done on this subject (Herbig 1985, Pasquini & Pallavicini 1991. The chromospheric diagnostic was built with a…

Astrophysics · Physics 2015-06-24 W. Lyra , G. F. Porto de Mello

Nucleocosmochronology involves the use of the abundances of radioactive nuclear species and their radiogenic decay daughters to establish the finite age of the elements and the time scale for their formation. While there exist radioactive…

Astrophysics · Physics 2007-05-23 J. W. Truran , S. Burles , J. J. Cowan , C. Sneden

Stellar ages are extremely difficult to determine and often subject to large uncertainties, especially for field low-mass stars. We plan to carry out a calibration of the decrease in high-energy emissions of low-mass GKM stars with time,…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. Garcés , S. Catalán , I. Ribas

We show that there is a relationship between the age excess, defined as the difference between the stellar isochrone and chromospheric ages, and the metallicity as measured by the index [Fe/H] for late-type dwarfs. The chromospheric age…

Astrophysics · Physics 2016-08-30 H. J. Rocha-Pinto , W. J. Maciel

The past two decades have seen dramatic progress in our knowledge of the population of young stars of age <200 Myr that lie within 150 pc of the Sun. These nearby, young stars, most of which are found in loose, comoving groups, provide the…

Solar and Stellar Astrophysics · Physics 2019-03-06 Joel Kastner , Matthieu Chalifour , Alex Binks , David Rodriguez , Kristina Punz , G. G. Sacco

Age is a fundamental parameter of stars, yet in many cases ages of individual stars are presented without robust estimates of the uncertainty. We have developed a Bayesian framework, BAFFLES, to produce the age posterior for a star from its…

Solar and Stellar Astrophysics · Physics 2020-10-07 S Adam Stanford-Moore , Eric L. Nielsen , Robert J. De Rosa , Bruce Macintosh , Ian Czekala

Stars with convective envelopes display magnetic activity, which decreases over time due to the magnetic braking of the star. This age-dependence of magnetic activity is well-studied for younger stars, but the nature of this dependence for…

Solar and Stellar Astrophysics · Physics 2017-08-16 R. S. Booth , K. Poppenhaeger , C. A. Watson , V. Silva Aguirre , S. J. Wolk

We present an analysis of the positions and ages of young star clusters in eight local galaxies to investigate the connection between the age difference and separation of cluster pairs. We find that star clusters do not form uniformly but…

Context: Knowledge of the age distribution of stars in young clusters and associations is crucial to constrain models of star formation. HR diagrams of different young clusters and associations suggest the presence of age spreads, but the…

Astrophysics · Physics 2009-11-11 G. G. Sacco , S. Randich , E. Franciosini , R. Pallavicini , F. Palla