Suchergebnisse

Monteiro, Mario J. P. F. G./0000-0003-0513-8116; Suarez, Juan Carlos/0000-0003-3649-8384; Serenelli, Aldo/0000-0001-6359-2769; Jiang, Chen/0000-0002-7614-1665; Slumstrup, Ditte/0000-0003-4538-9518; Mathur, Savita/0000-0002-0129-0316; Christensen-Dalsgaard, Jorgen/0000-0001-5137-0966; Bodi, Attila/0000-0002-8585-4544; Pereira, Filipe/0000-0002-2157-7146; YILDIZ, Mutlu/0000-0002-7772-7641; Di Mauro, Maria Pia/0000-0001-7801-7484; Ball, Warrick/0000-0002-4773-1017; Spitoni, Emanuele/0000-0001-9715-5727; Handberg, Rasmus/0000-0001-8725-4502; Lustosa de Moura, Bruno/0000-0001-6295-3526; Lund, Mikkel Norup/0000-0001-9214-5642; Rodriguez Diaz, Luisa Fernanda/0000-0002-0588-1375; Basu, Sarbani/0000-0002-6163-3472; Stokholm, Amalie/0000-0002-5496-365X; Cunha, Margarida/0000-0001-8237-7343; miglio, andrea/0000-0001-5998-8533; BUGNET, Lisa/0000-0003-0142-4000; Buzasi, Derek/0000-0002-1988-143X; Van Eylen, Vincent/0000-0001-5542-8870; Stello, Dennis/0000-0002-4879-3519; Lysgaard Rorsted, Jakob/0000-0001-9234-430X; Angelou, George/0000-0003-4463-1907; Mosser, Benoit/0000-0002-7547-1208; Verma, Kuldeep/0000-0003-0970-6440; Kuszlewicz, James/0000-0002-3322-5279; Bell, Keaton/0000-0002-0656-032X; Huber, Daniel/0000-0001-8832-4488; Lundkvist, Mia Sloth/0000-0002-8661-2571 ; WOS: 000520956000001 ; Since the onset of the "space revolution" of high-precision high-cadence photometry, asteroseismology has been demonstrated as a powerful tool for informing Galactic archeology investigations. the launch of the NASA Transiting Exoplanet Survey Satellite (TESS) mission has enabled seismic-based inferences to go full sky-providing a clear advantage for large ensemble studies of the different Milky Way components. Here we demonstrate its potential for investigating the Galaxy by carrying out the first asteroseismic ensemble study of red giant stars observed by TESS. We use a sample of 25 stars for which we measure their global asteroseimic observables and estimate their fundamental stellar properties, such as radius, mass, and age. Significant improvements are seen in the uncertainties of our estimates when combining seismic observables from TESS with astrometric measurements from the Gaia mission compared to when the seismology and astrometry are applied separately. Specifically, when combined we show that stellar radii can be determined to a precision of a few percent, masses to 5%-10%, and ages to the 20% level. This is comparable to the precision typically obtained using end-of-mission Kepler data. ; NASA's Science Mission directorate; Danish National Research FoundationDanmarks Grundforskningsfond [DNRF106]; ESA PRODEXEuropean Space Agency [PEA 4000119301]; Stellar Astrophysics Centre (SAC) at Aarhus University; Independent Research Fund Denmark [7027-00096B]; FCT/MCTESPortuguese Foundation for Science and Technology [UID/FIS/04434/2019, PTDC/FIS-AST/30389/2017, POCI-01-0145-FEDER-030389, CEECIND/02619/2017]; FEDER through COMPETE2020 [UID/FIS/04434/2019, PTDC/FIS-AST/30389/2017, POCI-01-0145-FEDER-030389, CEECIND/02619/2017]; CNES/PLATO grant; NASANational Aeronautics & Space Administration (NASA) [NNX16AB76G]; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreementEuropean Union (EU) [792848, 664931]; ESA PRODEX programme; Premiale 2015 MITiC; National Science FoundationNational Science Foundation (NSF) [AST-1903828]; Carlsberg FoundationCarlsberg Foundation [CF17-0760]; European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant [338251]; European Research CouncilEuropean Research Council (ERC) [772293]; MINECO [ESP2017-82674R]; Spanish public funds for research [ESP2017-87676-2-2]; Spanish Ministry of Science and EducationSpanish Government [RYC-2012-09913] ; This Letter includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA's Science Mission directorate. Funding for the TESS Asteroseismic Science Operations Centre is provided by the Danish National Research Foundation (grant agreement No. DNRF106), ESA PRODEX (PEA 4000119301), and Stellar Astrophysics Centre (SAC) at Aarhus University. V.S. A. acknowledges support from the Independent Research Fund Denmark (Research grant 7027-00096B). D.B. is supported in the form of work contract FCT/MCTES through national funds and by FEDER through COMPETE2020 in connection to these grants: UID/FIS/04434/2019; PTDC/FIS-AST/30389/2017 & POCI-01-0145-FEDER-030389. L.B., R.A.G., and B.M. acknowledge the support from the CNES/PLATO grant. D.B. acknowledges NASA grant NNX16AB76G. T.L.C. acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.792848 (PULSATION). This work was supported by FCT/MCTES through national funds (UID/FIS/04434/2019). E.C. is funded by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 664931. R.H. and M.N.L. acknowledge the support of the ESA PRODEX programme. T.S.R. acknowledges financial support from Premiale 2015 MITiC (PI B. Garilli). K.J.B. is supported by the National Science Foundation under Award AST-1903828. M. S.L. is supported by the Carlsberg Foundation (grant agreement No. CF17-0760). M.C. is funded by FCT//MCTES through national funds and by FEDER through COMPETE2020 through these grants: UID/FIS/04434/2019, PTDC/FIS-AST/30389/2017 & POCI-01-0145-FEDER-030389, CEECIND/02619/2017. the research leading to the presented results has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no 338251 (StellarAges). A.M. acknowledges support from the European Research Council Consolidator Grant funding scheme (project ASTEROCHRONOMETRY, grant agreement No. 772293,.http://www.asterochronometry.eu).A.M.S.is partially supported by MINECO grant ESP2017-82674R. J.C.S. acknowledges funding support from Spanish public funds for research under projects ESP2017-87676-2-2, and from project RYC-2012-09913 under the `Ramon y Cajal' program of the Spanish Ministry of Science and Education. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products.

[Contact] The large quantity of high-quality asteroseismic data that have been obtained from space-based photometric missions and the accuracy of the resulting frequencies motivate a careful consideration of the accuracy of computed oscillation frequencies of stellar models, when applied as diagnostics of the model properties. ; [Aims] Based on models of red-giant stars that have been independently calculated using different stellar evolution codes, we investigate the extent to which the differences in the model calculation affect the model oscillation frequencies and other asteroseismic diagnostics. ; [Methods] For each of the models, which cover four different masses and different evolution stages on the red-giant branch, we computed full sets of low-degree oscillation frequencies using a single pulsation code and, from these frequencies, typical asteroseismic diagnostics. In addition, we carried out preliminary analyses to relate differences in the oscillation properties to the corresponding model differences. ; [Results] In general, the differences in asteroseismic properties between the different models greatly exceed the observational precision of these properties. This is particularly true for the nonradial modes whose mixed acoustic and gravity-wave character makes them sensitive to the structure of the deep stellar interior and, hence, to details of their evolution. In some cases, identifying these differences led to improvements in the final models presented here and in Paper I; here we illustrate particular examples of this. ; [Conclusions] Further improvements in stellar modelling are required in order fully to utilise the observational accuracy to probe intrinsic limitations in the modelling and improve our understanding of stellar internal physics. However, our analysis of the frequency differences and their relation to stellar internal properties provides a striking illustration of the potential, in particular, of the mixed modes of red-giant stars for the diagnostics of stellar interiors. ; Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement No. DNRF106). The research was supported by the ASTERISK project (ASTERoseismic Investigations with SONG and Kepler) funded by the European Research Council (Grant agreement No. 267864). This research was supported in part by the National Science Foundation under Grant No. NSF PHY-1748958. VSA acknowledges support from VILLUM FONDEN (research grant 10118) and the Independent Research Fund Denmark (Research grant 7027-00096B). DS is the recipient of an Australian Research Council Future Fellowship (project number FT1400147). SC acknowledges support from Premiale INAF MITiC, from INAF "Progetto mainstream" (PI: S. Cassisi), and grant AYA2013-42781P from the Ministry of Economy and Competitiveness of Spain. AMS is partially supported by grants ESP2017-82674-R (Spanish Government) and 2017-SGR-1131 (General-itat de Catalunya). TC acknowledges support from the European Research Council AdG No 320478-TOFU and the STFC Consolidated Grant ST/R000395/1. SH received funding for this research from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no 338251 (StellarAges). AM acknowledges the support of the Government of India, Department of Atomic Energy, under Project No. 12-R&D-TFR-6.04-0600. DB is supported in the form of work contract FCT/MCTES through national funds and by FEDER through COMPETE2020 in connection to these grants: UID/FIS/04434/2019; PTDC/FIS-AST/30389/2017 & POCI-01-0145-FEDER-030389.