Stahn, Thorsten

[["dc.bibliographiccitation.artnumber","L10"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","748"],["dc.contributor.author","Metcalfe, T. S."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Appourchaux, Thierry"],["dc.contributor.author","García, R. A."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Brandão, I. M."],["dc.contributor.author","Creevey, O. L."],["dc.contributor.author","Deheuvels, S."],["dc.contributor.author","Doğan, G."],["dc.contributor.author","Eggenberger, P."],["dc.contributor.author","Karoff, C."],["dc.contributor.author","Miglio, A."],["dc.contributor.author","Stello, D."],["dc.contributor.author","Yıldız, M."],["dc.contributor.author","Çelik, Z."],["dc.contributor.author","Antia, H. M."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Howe, R."],["dc.contributor.author","Régulo, C."],["dc.contributor.author","Salabert, D."],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Bedding, T. R."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Elsworth, Y."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Hekker, S."],["dc.contributor.author","Mathur, Saurabh"],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Bryson, S. T."],["dc.contributor.author","Still, M. D."],["dc.contributor.author","Christensen-Dalsgaard, J."],["dc.contributor.author","Gilliland, R. L."],["dc.contributor.author","Kawaler, S. D."],["dc.contributor.author","Kjeldsen, H."],["dc.contributor.author","Ibrahim, K. A."],["dc.contributor.author","Klaus, T. C."],["dc.contributor.author","Li, J."],["dc.date.accessioned","2017-09-07T11:49:58Z"],["dc.date.available","2017-09-07T11:49:58Z"],["dc.date.issued","2012"],["dc.description.abstract","The evolved solar-type stars 16 Cyg A and B have long been studied as solar analogs, yielding a glimpse into the future of our own Sun. The orbital period of the binary system is too long to provide meaningful dynamical constraints on the stellar properties, but asteroseismology can help because the stars are among the brightest in the Kepler field. We present an analysis of three months of nearly uninterrupted photometry of 16 Cyg A and B from the Kepler space telescope. We extract a total of 46 and 41 oscillation frequencies for the two components, respectively, including a clear detection of octupole (l = 3) modes in both stars. We derive the properties of each star independently using the Asteroseismic Modeling Portal, fitting the individual oscillation frequencies and other observational constraints simultaneously. We evaluate the systematic uncertainties from an ensemble of results generated by a variety of stellar evolution codes and fitting methods. The optimal models derived by fitting each component individually yield a common age (t = 6.8 ± 0.4 Gyr) and initial composition (Z i = 0.024 ± 0.002, Y i = 0.25 ± 0.01) within the uncertainties, as expected for the components of a binary system, bolstering our confidence in the reliability of asteroseismic techniques. The longer data sets that will ultimately become available will allow future studies of differential rotation, convection zone depths, and long-term changes due to stellar activity cycles."],["dc.identifier.doi","10.1088/2041-8205/748/1/l10"],["dc.identifier.gro","3147458"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5016"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","2041-8205"],["dc.title","Asteroseismology of the Solar Aanalogs 16 Cyg A and B from Kepler Observations"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","257"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Space Science Reviews"],["dc.bibliographiccitation.lastpage","258"],["dc.bibliographiccitation.volume","156"],["dc.contributor.author","Gizon, L."],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Baldner, C. S."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Birch, A. C."],["dc.contributor.author","Bogart, R. S."],["dc.contributor.author","Braun, D. C."],["dc.contributor.author","Cameron, R. H."],["dc.contributor.author","Duvall Jr., T. L."],["dc.contributor.author","Hanasoge, S. M."],["dc.contributor.author","Jackiewicz, J."],["dc.contributor.author","Roth, M."],["dc.contributor.author","Stahn, T."],["dc.contributor.author","Thompson, M. J."],["dc.contributor.author","Zharkov, S."],["dc.date.accessioned","2017-09-07T11:48:39Z"],["dc.date.available","2017-09-07T11:48:39Z"],["dc.date.issued","2010"],["dc.identifier.doi","10.1007/s11214-010-9688-1"],["dc.identifier.gro","3146992"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4741"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.eissn","1572-9672"],["dc.relation.iserratumof","/handle/2/4740"],["dc.relation.issn","0038-6308"],["dc.title","Erratum to: Helioseismology of Sunspots: A Case Study of NOAA Region 9787"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.subtype","erratum_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","249"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Space Science Reviews"],["dc.bibliographiccitation.lastpage","273"],["dc.bibliographiccitation.volume","144"],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Baldner, C. S."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Birch, Aaron C."],["dc.contributor.author","Bogart, R. S."],["dc.contributor.author","Braun, D. C."],["dc.contributor.author","Cameron, R. H."],["dc.contributor.author","Duvall, Thomas L."],["dc.contributor.author","Hanasoge, Shravan M."],["dc.contributor.author","Jackiewicz, J."],["dc.contributor.author","Roth, M."],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Thompson, M. J."],["dc.contributor.author","Zharkov, S."],["dc.date.accessioned","2017-09-07T11:48:39Z"],["dc.date.available","2017-09-07T11:48:39Z"],["dc.date.issued","2008"],["dc.identifier.doi","10.1007/s11214-008-9466-5"],["dc.identifier.gro","3146991"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4740"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.publisher","Springer Nature"],["dc.relation.haserratum","/handle/2/4741"],["dc.relation.issn","0038-6308"],["dc.title","Helioseismology of Sunspots: A Case Study of NOAA Region 9787"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","19"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","756"],["dc.contributor.author","Deheuvels, S."],["dc.contributor.author","Garcia, R. A."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Antia, H. M."],["dc.contributor.author","Appourchaux, T."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Elsworth, Yvonne P."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Goupil, M. J."],["dc.contributor.author","Reese, Daniel R."],["dc.contributor.author","Regulo, C."],["dc.contributor.author","Schou, Jesper"],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Casagrande, Luca"],["dc.contributor.author","Christensen-Dalsgaard, Joergen"],["dc.contributor.author","Fischer, D."],["dc.contributor.author","Hekker, Saskia"],["dc.contributor.author","Kjeldsen, Hans"],["dc.contributor.author","Mathur, S."],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Pinsonneault, M."],["dc.contributor.author","Valenti, Jeff A."],["dc.contributor.author","Christiansen, Jessie L."],["dc.contributor.author","Kinemuchi, K."],["dc.contributor.author","Mullally, F."],["dc.date.accessioned","2018-11-07T09:06:21Z"],["dc.date.available","2018-11-07T09:06:21Z"],["dc.date.issued","2012"],["dc.description.abstract","Rotation is expected to have an important influence on the structure and the evolution of stars. However, the mechanisms of angular momentum transport in stars remain theoretically uncertain and very complex to take into account in stellar models. To achieve a better understanding of these processes, we desperately need observational constraints on the internal rotation of stars, which until very recently was restricted to the Sun. In this paper, we report the detection of mixed modes-i.e., modes that behave both as g modes in the core and as p modes in the envelope-in the spectrum of the early red giant KIC 7341231, which was observed during one year with the Kepler spacecraft. By performing an analysis of the oscillation spectrum of the star, we show that its non-radial modes are clearly split by stellar rotation and we are able to determine precisely the rotational splittings of 18 modes. We then find a stellar model that reproduces very well the observed atmospheric and seismic properties of the star. We use this model to perform inversions of the internal rotation profile of the star, which enables us to show that the core of the star is rotating at least five times faster than the envelope. This will shed new light on the processes of transport of angular momentum in stars. In particular, this result can be used to place constraints on the angular momentum coupling between the core and the envelope of early red giants, which could help us discriminate between the theories that have been proposed over the last few decades."],["dc.identifier.doi","10.1088/0004-637X/756/1/19"],["dc.identifier.gro","3147417"],["dc.identifier.isi","000309044300019"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/25539"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1538-4357"],["dc.relation.issn","0004-637X"],["dc.title","Seismic Evidence for a Rapidly Rotating Core in a Lower-Giant-Branch Star Observed with Kepler"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","L10"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","748"],["dc.contributor.author","Metcalfe, T. S."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Appourchaux, T."],["dc.contributor.author","Garcia, R. A."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Brandao, Ines"],["dc.contributor.author","Creevey, O. L."],["dc.contributor.author","Deheuvels, S."],["dc.contributor.author","Dogan, G."],["dc.contributor.author","Eggenberger, P."],["dc.contributor.author","Karoff, Christoffer"],["dc.contributor.author","Miglio, Andrea"],["dc.contributor.author","Stello, Dennis"],["dc.contributor.author","Yildiz, M."],["dc.contributor.author","Celik, Z."],["dc.contributor.author","Antia, H. M."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Howe, R."],["dc.contributor.author","Regulo, C."],["dc.contributor.author","Salabert, D."],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Bedding, Timothy R."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Elsworth, Yvonne P."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Hekker, Saskia"],["dc.contributor.author","Mathur, S."],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Bryson, Steven T."],["dc.contributor.author","Still, M. D."],["dc.contributor.author","Christensen-Dalsgaard, Joergen"],["dc.contributor.author","Gilliland, Ronald L."],["dc.contributor.author","Kawaler, Steven D."],["dc.contributor.author","Kjeldsen, Hans"],["dc.contributor.author","Ibrahim, K. A."],["dc.contributor.author","Klaus, Todd C."],["dc.contributor.author","Li, J."],["dc.date.accessioned","2018-11-07T09:12:15Z"],["dc.date.available","2018-11-07T09:12:15Z"],["dc.date.issued","2012"],["dc.description.abstract","The evolved solar-type stars 16 Cyg A and B have long been studied as solar analogs, yielding a glimpse into the future of our own Sun. The orbital period of the binary system is too long to provide meaningful dynamical constraints on the stellar properties, but asteroseismology can help because the stars are among the brightest in the Kepler field. We present an analysis of three months of nearly uninterrupted photometry of 16 Cyg A and B from the Kepler space telescope. We extract a total of 46 and 41 oscillation frequencies for the two components, respectively, including a clear detection of octupole (l = 3) modes in both stars. We derive the properties of each star independently using the Asteroseismic Modeling Portal, fitting the individual oscillation frequencies and other observational constraints simultaneously. We evaluate the systematic uncertainties from an ensemble of results generated by a variety of stellar evolution codes and fitting methods. The optimal models derived by fitting each component individually yield a common age (t = 6.8 +/- 0.4 Gyr) and initial composition (Z(i) = 0.024 +/- 0.002, Y-i = 0.25 +/- 0.01) within the uncertainties, as expected for the components of a binary system, bolstering our confidence in the reliability of asteroseismic techniques. The longer data sets that will ultimately become available will allow future studies of differential rotation, convection zone depths, and long-term changes due to stellar activity cycles."],["dc.identifier.doi","10.1088/2041-8205/748/1/L10"],["dc.identifier.isi","000301297500010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26907"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","2041-8205"],["dc.title","Asteroseismology of the Solar Analogs 16 Cyg A and B from Kepler Observations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]