J/A+A/426/247ivo://CDS.VizieR/J/A+A/426/247doi:10.26093/cds/vizier.34260247CDSChapellier E.Mathias P.Garrido R.Le Contel J.-M.Sareyan J.-P.,Ribas I.Parrao L.Moya A.Pena J.H.Alvarez M.2017-06-01T08:52:04Z2005-01-01T23:06:37ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frvariable-starsradial-velocityvisible-astronomymedium-band-photometryWe present spectroscopic and photometric observations of the star HD 173977. It appears that the star is part of a double line binary system, with a period of 1.801d, corresponding to twice the period of the photometric variations. Hence the star is an ellipsoidal variable. The system is probably synchronized. The physical parameters of both components were derived through two independent methods, one based on evolutionary tracks, the other being the result of the behaviour of light curves in a close binary system. After removing the ellipsoidal variations, 3 frequencies are detected in the photometric data: 8.56, 14.51 and 16.42d^-1^, while 2 additional frequencies are also possible: 10.96 and 12.11d^-1^. In accordance with its position in the HR diagram, the primary component of HD 173977 should be considered as a delta Scuti star and no longer as a gamma Doradus star. In addition, HD 173844, used as a check star, is discovered variable with a 15.79d^-1^ frequency and is classified as a delta Scuti star.2004A&A...426..247Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/426/247CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/426/247https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/426/247http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/426/247https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/426/247https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/426/247http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/426/247GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/426/247/table1Radial velocity data for the star and its companionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intHJDHeliocentric Julian dateddoubleHRV1? Heliocentric radial velocity of component 1km/sfloatnullableHRV2? Heliocentric radial velocity of component 2km/sfloatnullableJ/A+A/426/247/table2Photometric data (HD 173977 - HD 173663) in Stroemgren filtersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intHJDHeliocentric Julian dateddoublevmagStroemgren differential v magnitudemagfloatbmagStroemgren differential b magnitudemagfloatymagStroemgren differential y magnitudemagfloat