J/A+A/304/415ivo://CDS.VizieR/J/A+A/304/415doi:10.26093/cds/vizier.33040415CDSvan Genderen A.M.Sterken C.de Groot M.Stahl O.Andersen J.,Andersen M.I.Caldwell J.A.R.Casey B.Clement R.Corradi W.J.B.,Cuypers J.Debehogne H.Garcia de Maria J.M.Joench-Soerensen H.,Vaz L.P.R.Stefl S.Suso Lopez J.Beele D.Eggenkamp I.M.M.G.,Goecking K.-D.Jorissen A.de Koff S.Kuss C.Schoenmakers A.P.,Vink J.Waelde E.1997-12-09T16:38:06Z1997-12-09T17:38:03ZCDS support team

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

cds-question@unistra.frvariable-starssupergiant-starsvisible-astronomymedium-band-photometryWe present and analyze two seasons of intense photometric monitoring in the Stroemgren uvbyH{beta} system of {eta} Carinae (October 1992-August 1994). The luminous blue variable (LBV) in the core did not show much S Dor activity, i.e. it was in a relatively quiescent stage. This situation was very favourable for studying its optical micro variations. It appears that the central LBV pulsates (presumably in a non-radial mode) like other massive evolved stars, the {alpha} Cyg variables. The quasi-period is 58.56d. The linear ephemeris is: JD_max_=2448875.0 +58.56 E. Support was found for the existence of the presumed periodicity of 52.4d of the so-called "dimples", shallow dips in the light curve which only last for a few days. The cause may be the eclipse of a small companion or of a hot spot in an accretion disk. The H{beta} index became bluer by ~0.07mag during the last 11/2 years and shows an oscillation in anti-phase with the 58.56d pulsation, suggesting that the HII region(s) responsible for the hydrogen line emission has a relatively high luminosity. This is another reason to suppose that a second luminous source, perhaps a luminous disk (with a hot spot), may be present in the {eta} Car system. Objects concerned: -------------------------------------------------- RA (2000) DE Name(s) -------------------------------------------------- 10 45 03.6 -59 41 03 eta Car = HR 4210 = HD 93308 --------------------------------------------------1995A&A...304..415Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/304/415CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJS/71/983 : UV spectrum of eta Car (Viotti+ 1989)J/A+A/304/415 : uvby-Hbeta photometry of Eta Car 1992-94 (van Genderen+, 1995)J/A+A/343/847 : Geneva Photometry of Eta Car (van Genderen+ 1999)J/A+A/419/215 : Emission lines of eta Car (Hartman+, 2004)J/AJ/129/2018 : RXTE scaled fluxes of eta Car (Corcoran+, 2005)J/ApJS/157/138 : UV spectrum of eta Car (Nielsen+, 2005)J/ApJS/163/173 : UV spectrum of eta Car in 2003.5 (Gull+, 2006)J/ApJS/168/289 : NUV spectrum of eta Car in 2003.5 (Nielsen+, 2007)J/A+A/493/1093 : BVRI light curves of eta Car (Fernandez-Lajus+, 2009)J/ApJS/181/473 : Eta Carinae: visible and near-IR analysis (Nielsen+, 2009)J/other/NewA/15.108 : UBVRIHalpha of eta Car in 2009 (Fernandez-Lajus+ 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/304/415https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/304/415http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/304/415https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/304/415https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/304/415http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/304/415GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/304/415/table1Stroemgren uvbyH-beta photometry of Eta CarrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian datedtime.epochdoubleu_JD[:] Uncertainty flag on JDmeta.code.errorcharymag[]? y Stroemgren magnitudemagphot.mag;em.opt.Vfloatbmag[]? b Stroemgren magnitudemagphot.mag;em.opt.Bfloatvmag[]? v Stroemgren magnitudemagphot.mag;em.opt.Bfloatumag[]? u Stroemgren magnitudemagphot.mag;em.opt.UfloatHbmag[]? H{beta} Stroemgren magnitudemagspect.indexfloat