Stahn, Thorsten

[["dc.bibliographiccitation.artnumber","A96"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","543"],["dc.contributor.author","Escobar, M. E."],["dc.contributor.author","Théado, S."],["dc.contributor.author","Vauclair, S."],["dc.contributor.author","Ballot, J."],["dc.contributor.author","Charpinet, S."],["dc.contributor.author","Dolez, N."],["dc.contributor.author","Hui-Bon-Hoa, A."],["dc.contributor.author","Vauclair, G."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Mathur, Saurabh"],["dc.contributor.author","Quirion, P.-O."],["dc.contributor.author","Stahn, Thorsten"],["dc.date.accessioned","2017-09-07T11:48:39Z"],["dc.date.available","2017-09-07T11:48:39Z"],["dc.date.issued","2012"],["dc.identifier.doi","10.1051/0004-6361/201218969"],["dc.identifier.fs","596686"],["dc.identifier.gro","3146982"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9609"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4736"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Precise modeling of the exoplanet host star and CoRoT main target HD 52265"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","231"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Astrophysics and Space Science"],["dc.bibliographiccitation.lastpage","242"],["dc.bibliographiccitation.volume","329"],["dc.contributor.author","Schuh, Sonja"],["dc.contributor.author","Silvotti, Roberto"],["dc.contributor.author","Lutz, Ronny"],["dc.contributor.author","Loeptien, Bjoern"],["dc.contributor.author","Green, Elizabeth M."],["dc.contributor.author","Ostensen, Roy H."],["dc.contributor.author","Leccia, Silvio"],["dc.contributor.author","Kim, Seung-Lee"],["dc.contributor.author","Fontaine, Gilles"],["dc.contributor.author","Charpinet, Stephane"],["dc.contributor.author","Francoeur, Myriam"],["dc.contributor.author","Randall, Suzanna"],["dc.contributor.author","Rodriguez-Lopez, Cristina"],["dc.contributor.author","van Grootel, Valerie"],["dc.contributor.author","Odell, Andrew P."],["dc.contributor.author","Paparo, Margit"],["dc.contributor.author","Bognar, Zsofia"],["dc.contributor.author","Papics, Peter"],["dc.contributor.author","Nagel, Thorsten"],["dc.contributor.author","Beeck, Benjamin"],["dc.contributor.author","Hundertmark, Markus"],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Hessman, Frederic V."],["dc.contributor.author","Dall'Ora, Massimo"],["dc.contributor.author","Mancini, Dario"],["dc.contributor.author","Cortecchia, Fausto"],["dc.contributor.author","Benatti, Serena"],["dc.contributor.author","Claudi, Riccardo"],["dc.contributor.author","Janulis, Rimvydas"],["dc.date.accessioned","2018-11-07T08:38:16Z"],["dc.date.available","2018-11-07T08:38:16Z"],["dc.date.issued","2010"],["dc.description.abstract","In 2007, a companion with planetary mass was found around the pulsating subdwarf B star V391 Pegasi with the timing method, indicating that a previously undiscovered population of substellar companions to apparently single subdwarf B stars might exist. Following this serendipitous discovery, the EXOTIME (http://www.na.astro.it/similar to silvotti/exotime/)) monitoring program has been set up to follow the pulsations of a number of selected rapidly pulsating subdwarf B stars on time scales of several years with two immediate observational goals: (1) determine (P)over dot of the pulsational periods P (2) search for signatures of substellar companions in O-C residuals due to periodic light travel time variations, which would be tracking the central star's companion-induced wobble around the centre of mass These sets of data should therefore, at the same time, on the one hand be useful to provide extra constraints for classical asteroseismological exercises from the P. ( comparison with \"local\" evolutionary models), and on the other hand allow one to investigate the preceding evolution of a target in terms of possible \"binary\" evolution by extending the otherwise unsuccessful search for companions to potentially very low masses. While timing pulsations may be an observationally expensive method to search for companions, it samples a different range of orbital parameters, inaccessible through orbital photometric effects or the radial velocity method: the latter favours massive close-in companions, whereas the timing method becomes increasingly more sensitive toward wider separations. In this paper we report on the status of the on-going observations and coherence analysis for two of the currently five targets, revealing very well-behaved pulsational characteristics in HS 0444+0458, while showing HS 0702+6043 to be more complex than previously thought."],["dc.identifier.doi","10.1007/s10509-010-0356-4"],["dc.identifier.isi","000282823200038"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7631"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18728"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0004-640X"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","EXOTIME: searching for planets around pulsating subdwarf B stars"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A82"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","601"],["dc.contributor.author","White, Timothy R."],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Aguirre, Victor Silva"],["dc.contributor.author","Ball, Warrick H."],["dc.contributor.author","Bedding, Timothy R."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Christensen-Dalsgaard, Joergen"],["dc.contributor.author","Garcia, R. A."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Stello, Dennis"],["dc.contributor.author","Aigrain, S."],["dc.contributor.author","Antia, H. M."],["dc.contributor.author","Appourchaux, T."],["dc.contributor.author","Bazot, M."],["dc.contributor.author","Campante, Tiago L."],["dc.contributor.author","Creevey, O. L."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Elsworth, Yvonne P."],["dc.contributor.author","Gaulme, P."],["dc.contributor.author","Handberg, Rasmus"],["dc.contributor.author","Hekker, Saskia"],["dc.contributor.author","Houdek, Gunter"],["dc.contributor.author","Howe, R."],["dc.contributor.author","Huber, D."],["dc.contributor.author","Karoff, Christoffer"],["dc.contributor.author","Marques, J. P."],["dc.contributor.author","Mathur, S."],["dc.contributor.author","McQuillan, A."],["dc.contributor.author","Metcalfe, T. S."],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Nielsen, M. B."],["dc.contributor.author","Regulo, C."],["dc.contributor.author","Salabert, D."],["dc.contributor.author","Stahn, Thorsten"],["dc.date.accessioned","2018-11-07T10:24:05Z"],["dc.date.available","2018-11-07T10:24:05Z"],["dc.date.issued","2017"],["dc.description.abstract","Binary star systems are important for understanding stellar structure and evolution, and are especially useful when oscillations can be detected and analysed with asteroseismology. However, only four systems are known in which solar-like oscillations are detected in both components. Here, we analyse the fifth such system, HD 176465, which was observed by Kepler. We carefully analysed the system's power spectrum to measure individual mode frequencies, adapting our methods where necessary to accommodate the fact that both stars oscillate in a similar frequency range. We also modelled the two stars independently by fitting stellar models to the frequencies and complementary parameters. We are able to cleanly separate the oscillation modes in both systems. The stellar models produce compatible ages and initial compositions for the stars, as is expected from their common and contemporaneous origin. Combining the individual ages, the system is about 3.0 +/- 0.5 Gyr old. The two components of HD 176465 are young physically-similar oscillating solar analogues, the first such system to be found, and provide important constraints for stellar evolution and asteroseismology."],["dc.identifier.doi","10.1051/0004-6361/201628706"],["dc.identifier.isi","000402313500082"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42591"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Edp Sciences S A"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/338251/EU//STELLARAGES"],["dc.relation.issn","1432-0746"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Kepler observations of the asteroseismic binary HD 176465"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","L25"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","L28"],["dc.bibliographiccitation.volume","448"],["dc.contributor.author","Nagel, T."],["dc.contributor.author","Schuh, Sonja"],["dc.contributor.author","Kusterer, D. J."],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Hugelmeyer, S. D."],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Gansicke, B. T."],["dc.contributor.author","Schreiber, M. R."],["dc.date.accessioned","2018-11-07T10:09:39Z"],["dc.date.available","2018-11-07T10:09:39Z"],["dc.date.issued","2006"],["dc.description.abstract","Aims. The archival spectrum of SDSS J212531.92- 010745.9 shows not only the typical signature of a PG1159 star, but also indicates the presence of a companion. Our aim was the proof of the binary nature of this object and the determination of its orbital period. Methods. We performed time-series photometry of SDSS J212531.92-010745.9. We observed the object during 10 nights, spread over one month, with the Tubingen 80 cm and the Gottingen 50 cm telescopes. We fitted the observed light curve with a sine and simulated the light curve of this system with the nightfall program. Furthermore, we compared the spectrum of SDSS J212531.92-010745.9 with NLTE models, the results of which also constrain the light curve solution. Results. An orbital period of 6.95616(33) h with an amplitude of 0.354(3) mag is derived from our observations. A pulsation period could not be detected. For the PG1159 star we found, as preliminary results from comparison with our NLTE models, T-eff similar to 90 000 K, log g similar to 7.60, and the abundance ratio C C/He similar to 0.05 by number fraction. For the companion we obtained with a mean radius of 0.4 +/- 0.1 R-., amass of 0.4 +/- 0.1 M-., and a temperature of 8200 K on the irradiated side, good agreement between the observed light curve and the, nightfall simulation, but we do not regard those values as final."],["dc.identifier.doi","10.1051/0004-6361:200600009"],["dc.identifier.isi","000235777700005"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7679"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/39691"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","SDSS J212531.92-010745.9 - the first definite PG 1159 close binary system"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","469"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","473"],["dc.bibliographiccitation.volume","496"],["dc.contributor.author","Lutz, R."],["dc.contributor.author","Schuh, Sonja"],["dc.contributor.author","Silvotti, Roberto"],["dc.contributor.author","Bernabei, S."],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Huegelmeyer, S. D."],["dc.date.accessioned","2018-11-07T08:31:50Z"],["dc.date.available","2018-11-07T08:31:50Z"],["dc.date.issued","2009"],["dc.description.abstract","Context. A noticeable fraction of subdwarf B stars shows either short-period (p-mode) or long-period (g-mode) luminosity variations, with two objects so far known to exhibit hybrid behaviour, i.e. showing both types of modes at the same time. The pulsating subdwarf B star V 391 Pegasi (or HS 2201+2610), which is close to the two known hybrid pulsators in the log g-T(eff) plane, has recently been discovered to host a planetary companion. Aims. In order to learn more about the planetary companion and its possible influence on the evolution of its host star (subdwarf B star formation is still not well understood), an accurate characterisation of the host star is required. As part of an ongoing effort to significantly improve the asteroseismic characterisation of the host star, we investigate the low-frequency behaviour of HS 2201+2610. Methods. We obtained rapid high signal-to-noise photometric CCD (B-filter) and PMT (clear-filter) data at 2m-class telescopes and carried out a careful frequency analysis of the light curves. Results. In addition to the previously known short-period luminosity variations in the range 342 s-367 s, we find a long-period variation with a period of 54 mn and an amplitude of 0.15 per cent. This can most plausibly be identified with a g-mode pulsation, so that HS 2201+2610 is a new addition to the short list of hybrid sdB pulsators. Conclusions. Along with the previously known pulsating subdwarf B stars HS 0702+6043 and Balloon 090100001 showing hybrid behaviour, the new hybrid HS 2201+2610 is the third member of this class. This important property of HS 2201+2610 can lead to a better characterisation of this planet-hosting star, helping the characterisation of its planetary companion as well. Current pulsation models cannot yet reproduce hybrid sdBV stars particularly well and improved pulsation models for this object have to include the hybrid behaviour."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [SCHU 2249/3-1]"],["dc.identifier.doi","10.1051/0004-6361/20079257"],["dc.identifier.fs","573288"],["dc.identifier.isi","000264405300019"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7675"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17209"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","The planet-hosting subdwarf B star V 391 Pegasi is a hybrid pulsator"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A27"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","564"],["dc.contributor.author","Deheuvels, S."],["dc.contributor.author","Doğan, G."],["dc.contributor.author","Goupil, M. J."],["dc.contributor.author","Appourchaux, Thierry"],["dc.contributor.author","Benomar, O."],["dc.contributor.author","Bruntt, H."],["dc.contributor.author","Campante, T. L."],["dc.contributor.author","Casagrande, L."],["dc.contributor.author","Ceillier, T."],["dc.contributor.author","Davies, G. R."],["dc.contributor.author","Cat, P. de"],["dc.contributor.author","Fu, J. N."],["dc.contributor.author","García, R. A."],["dc.contributor.author","Lobel, A."],["dc.contributor.author","Mosser, B."],["dc.contributor.author","Reese, D. R."],["dc.contributor.author","Regulo, C."],["dc.contributor.author","Schou, J."],["dc.contributor.author","Stahn, Thorsten"],["dc.contributor.author","Thygesen, A. O."],["dc.contributor.author","Yang, X. H."],["dc.contributor.author","Chaplin, W. J."],["dc.contributor.author","Christensen-Dalsgaard, J."],["dc.contributor.author","Eggenberger, P."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Mathur, Saurabh"],["dc.contributor.author","Molenda-Żakowicz, J."],["dc.contributor.author","Pinsonneault, M."],["dc.date.accessioned","2017-09-07T11:49:44Z"],["dc.date.available","2017-09-07T11:49:44Z"],["dc.date.issued","2014"],["dc.identifier.doi","10.1051/0004-6361/201322779"],["dc.identifier.fs","609656"],["dc.identifier.gro","3147416"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10916"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5002"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Seismic constraints on the radial dependence of the internal rotation profiles of sixKeplersubgiants and young red giants"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]