Ball, Warrick Heinz

[["dc.bibliographiccitation.artnumber","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal Supplement Series"],["dc.bibliographiccitation.volume","210"],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Huber, D."],["dc.contributor.author","Serenelli, A."],["dc.contributor.author","Casagrande, L."],["dc.contributor.author","Silva Aguirre, V."],["dc.contributor.author","Ball, Warrick H."],["dc.contributor.author","Creevey, O. L."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Handberg, R."],["dc.contributor.author","Karoff, C."],["dc.contributor.author","Lutz, R."],["dc.contributor.author","Marques, J. P."],["dc.contributor.author","Miglio, A."],["dc.contributor.author","Stello, D."],["dc.contributor.author","Suran, M. D."],["dc.contributor.author","Pricopi, D."],["dc.contributor.author","Metcalfe, T. S."],["dc.contributor.author","Monteiro, M. J. P. F. G."],["dc.contributor.author","Molenda-Żakowicz, J."],["dc.contributor.author","Appourchaux, Thierry"],["dc.contributor.author","Christensen-Dalsgaard, J."],["dc.contributor.author","Elsworth, Y."],["dc.contributor.author","García, R. A."],["dc.contributor.author","Houdek, G."],["dc.contributor.author","Kjeldsen, H."],["dc.contributor.author","Bonanno, A."],["dc.contributor.author","Campante, T. L."],["dc.contributor.author","Corsaro, E."],["dc.contributor.author","Gaulme, P."],["dc.contributor.author","Hekker, S."],["dc.contributor.author","Mathur, Saurabh"],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Régulo, C."],["dc.contributor.author","Salabert, D."],["dc.date.accessioned","2017-09-07T11:48:39Z"],["dc.date.available","2017-09-07T11:48:39Z"],["dc.date.issued","2013"],["dc.description.abstract","We use asteroseismic data obtained by the NASA Kepler mission to estimate the fundamental properties of more than 500 main-sequence and sub-giant stars. Data obtained during the first 10 months of Kepler science operations were used for this work, when these solar-type targets were observed for one month each in survey mode. Stellar properties have been estimated using two global asteroseismic parameters and complementary photometric and spectroscopic data. Homogeneous sets of effective temperatures, T eff, were available for the entire ensemble from complementary photometry; spectroscopic estimates of T eff and [Fe/H] were available from a homogeneous analysis of ground-based data on a subset of 87 stars. We adopt a grid-based analysis, coupling six pipeline codes to 11 stellar evolutionary grids. Through use of these different grid-pipeline combinations we allow implicitly for the impact on the results of stellar model dependencies from commonly used grids, and differences in adopted pipeline methodologies. By using just two global parameters as the seismic inputs we are able to perform a homogenous analysis of all solar-type stars in the asteroseismic cohort, including many targets for which it would not be possible to provide robust estimates of individual oscillation frequencies (due to a combination of low signal-to-noise ratio and short dataset lengths). The median final quoted uncertainties from consolidation of the grid-based analyses are for the full ensemble (spectroscopic subset) approximately 10.8% (5.4%) in mass, 4.4% (2.2%) in radius, 0.017 dex (0.010 dex) in log g, and 4.3% (2.8%) in mean density. Around 36% (57%) of the stars have final age uncertainties smaller than 1 Gyr. These ages will be useful for ensemble studies, but should be treated carefully on a star-by-star basis. Future analyses using individual oscillation frequencies will offer significant improvements on up to 150 stars, in particular for estimates of the ages, where having the individual frequency data is most important."],["dc.identifier.doi","10.1088/0067-0049/210/1/1"],["dc.identifier.gro","3146975"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4735"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","0067-0049"],["dc.title","Asteroseismic Fundamental Properties of Solar-Type Stars Observes by the NASA Kepler Mission"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1038"],["dc.bibliographiccitation.issue","956"],["dc.bibliographiccitation.journal","Publications of the Astronomical Society of the Pacific"],["dc.bibliographiccitation.lastpage","1044"],["dc.bibliographiccitation.volume","127"],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Lund, M. N."],["dc.contributor.author","Handberg, R."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Buchhave, L. A."],["dc.contributor.author","Campante, T. L."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Huber, D."],["dc.contributor.author","Latham, D. W."],["dc.contributor.author","Latham, C. A."],["dc.contributor.author","Serenelli, A."],["dc.contributor.author","Antia, H. M."],["dc.contributor.author","Appourchaux, Thierry"],["dc.contributor.author","Ball, Warrick H."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Casagrande, L."],["dc.contributor.author","Christensen-Dalsgaard, J."],["dc.contributor.author","Coelho, H. R."],["dc.contributor.author","Creevey, O. L."],["dc.contributor.author","Elsworth, Y."],["dc.contributor.author","García, R. A."],["dc.contributor.author","Gaulme, P."],["dc.contributor.author","Hekker, S."],["dc.contributor.author","Kallinger, T."],["dc.contributor.author","Karoff, C."],["dc.contributor.author","Kawaler, S. D."],["dc.contributor.author","Kjeldsen, H."],["dc.contributor.author","Lundkvist, M. S."],["dc.contributor.author","Marcadon, F."],["dc.contributor.author","Mathur, Saurabh"],["dc.contributor.author","Miglio, A."],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Régulo, C."],["dc.contributor.author","Roxburgh, I. W."],["dc.contributor.author","Silva Aguirre, V."],["dc.contributor.author","Stello, D."],["dc.contributor.author","Verma, K."],["dc.contributor.author","White, T. R."],["dc.contributor.author","Bedding, T. R."],["dc.contributor.author","Barclay, T."],["dc.contributor.author","Buzasi, D. L."],["dc.contributor.author","Dehuevels, S."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Houdek, G."],["dc.contributor.author","Howell, S. B."],["dc.contributor.author","Salabert, D."],["dc.contributor.author","Soderblom, D. R."],["dc.date.accessioned","2017-09-07T11:49:45Z"],["dc.date.available","2017-09-07T11:49:45Z"],["dc.date.issued","2015"],["dc.description.abstract","We present the first detections by the NASA K2 mission of oscillations in solar-type stars, using short-cadence data collected during K2 Campaign 1 (C1). We understand the asteroseismic detection thresholds for C1-like levels of photometric performance, and we can detect oscillations in subgiants having dominant oscillation frequencies around 1000 μHz. Changes to the operation of the fine-guidance sensors are expected to give significant improvements in the high-frequency performance from C3 onwards. A reduction in the excess high-frequency noise by a factor of 2.5 in amplitude would bring main-sequence stars with dominant oscillation frequencies as high as sime2500 μHz into play as potential asteroseismic targets for K2."],["dc.identifier.doi","10.1086/683103"],["dc.identifier.gro","3147413"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4998"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-6280"],["dc.title","Asteroseismology of Solar-Type Stars with K2: Detection of Oscillations in C1 Data"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4777"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Monthly Notices of the Royal Astronomical Society"],["dc.bibliographiccitation.lastpage","4788"],["dc.bibliographiccitation.volume","464"],["dc.contributor.author","Howe, R."],["dc.contributor.author","Basu, S."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Ball, Warrick H."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Elsworth, Yvonne P."],["dc.contributor.author","Komm, R."],["dc.date.accessioned","2018-11-07T10:27:47Z"],["dc.date.available","2018-11-07T10:27:47Z"],["dc.date.issued","2017"],["dc.description.abstract","The solar-cycle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic modes includes a significant frequency-dependent term known as the surface term, which is also related to the inverse mode inertia. We parametrize both the surface term and the frequency variations for low-degree solar data from Birmingham Solar-Oscillations Network (BiSON) and medium-degree data from the Global Oscillations Network Group (GONG) using the mode inertia together with cubic and inverse frequency terms. We find that for the central frequency of rotationally split multiplets, the cubic term dominates both the average surface term and the temporal variation, but for the medium-degree case, the inverse term improves the fit to the temporal variation. We also examine the variation of the even-order splitting coefficients for the medium-degree data and find that, as for the central frequency, the latitude-dependent frequency variation, which reflects the changing latitudinal distribution of magnetic activity over the solar cycle, can be described by the combination of a cubic and an inverse function of frequency scaled by inverse mode inertia. The results suggest that this simple parametrization could be used to assess the activity-related frequency variation in solar-like asteroseismic targets."],["dc.identifier.doi","10.1093/mnras/stw2668"],["dc.identifier.isi","000393780500073"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43297"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Oxford Univ Press"],["dc.relation.issn","1365-2966"],["dc.relation.issn","0035-8711"],["dc.title","Parametrizing the time variation of the 'surface term' of stellar p-mode frequencies: application to helioseismic data"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]