J/ApJ/751/73ivo://CDS.VizieR/J/ApJ/751/73doi:10.26093/cds/vizier.17510073CDSMehner A.Davidson K.Humphreys R.M.Ishibashi K.Martin J.C.,Ruiz M.T.Walter F.M.2017-06-21T08:21:52Z2014-02-03T13:06:21ZCDS support team

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

cds-question@unistra.frvariable-starsline-intensitiesStellar wind-emission features in the spectrum of eta Carinae have decreased by factors of 1.5-3 relative to the continuum within the last 10 years. We investigate a large data set from several instruments (STIS, GMOS, UVES) obtained between 1998 and 2011 and analyze the progression of spectral changes in direct view of the star, in the reflected polar-on spectra at FOS4, and at the Weigelt knots. We find that the spectral changes occurred gradually on a timescale of about 10 years and that they are dependent on the viewing angle. The line strengths declined most in our direct view of the star. About a decade ago, broad stellar wind-emission features were much stronger in our line-of-sight view of the star than at FOS4. After the 2009 event, the wind-emission line strengths are now very similar at both locations. High-excitation He I and N II absorption lines in direct view of the star strengthened gradually. The terminal velocity of Balmer P Cyg absorption lines now appears to be less latitude dependent, and the absorption strength may have weakened at FOS4. Latitude-dependent alterations in the mass-loss rate and the ionization structure of eta Carinae's wind are likely explanations for the observed spectral changes.2012ApJ...751...73Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/751/73CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/A+A/540/A133 : {eta} Car emission spectrum (1700-10400{AA}) (Zethson+, 2012)J/other/NewA/15.108 : UBVRIHa of {eta} Car in 2009 (Fernandez-Lajus+ 2010)J/ApJS/181/473 : Analysis of the spectrum of {eta} Car (Nielsen+, 2009)J/A+A/493/1093 : BVRI light curves of {eta} Car (Fernandez-Lajus+, 2009)J/AJ/135/1249 : The early spectra of eta Carinae (Humphreys+, 2008)J/ApJS/168/289 : NUV spectrum of eta Car in 2003.5 (Nielsen+, 2007)J/ApJS/163/173 : UV spectrum of eta Car in 2003.5 (Gull+, 2006)J/ApJS/157/138 : UV spectrum of eta Car (Nielsen+, 2005)J/AJ/129/2018 : RXTE scaled fluxes of eta Car (Corcoran+, 2005)J/A+A/419/215 : Emission lines of Sr filament near {eta} Car (Hartman+, 2004)J/A+A/343/847 : Geneva Photometry of Eta Car (van Genderen+ 1999)J/A+AS/133/299 : Long-term spectroscopy of eta Carinae (Damineli+ 1998)J/A+A/304/415 : uvby-Hb photometry of Eta Car 1992-94 (van Genderen+, 1995)J/ApJS/71/983 : UV spectrum of eta Car (Viotti+ 1989)http://etacar.umn.edu/ : HST Treasury Program on eta Carinaehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/751/73https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/751/73http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/751/73https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/751/73https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/751/73http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/751/73GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/751/73/table1*Equivalent widths of broad stellar wind-emission features (1998-2012)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintInstInstrument code (G1)meta.code;instrcharNameName (G2)meta.id;meta.mainchart2Link(s) to Halpha, Hdelta EWs (table 2)meta.numberintnullableDateObservation datetime.epoch;obsnullableMJDModified Julian Datedtime.epochfloatPhase[0.03/2.6] Phase in spectroscopic cycle (G3)time.phasefloatEW458[2.5/17.3]? EW of 4570-4600{AA} feature (1)0.1nmspect.line.eqWidthfloatnullablee_EW458[0/3.4]? EW458 uncertainty (1)0.1nmstat.errorfloatnullableEW463[0.1/16.2]? EW of 4614-4648{AA} feature (1)0.1nmspect.line.eqWidthfloatnullablee_EW463[0/3.8]? EW463 uncertainty (1)0.1nmstat.errorfloatnullableEW458p[0.3/6.7]? EW of 4570-4600{AA} feature at the FOS4 location (1)0.1nmspect.line.eqWidthfloatnullablee_EW458p[0/1.3]? EW458p uncertainty (1)0.1nmstat.errorfloatnullableJ/ApJ/751/73/table2Equivalent widths of H{alpha} and H{delta} (1998-2012)InstInstrument code (G1)meta.code;instrcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (G2)meta.id;meta.mainchart1Link(s) to EWs of broad stellar wind-emission features (table 1)meta.numberintnullableDateObservation datetime.epoch;obsnullableMJDModified Julian Datedtime.epochfloatPhase[0/2.6]? Phase in spectroscopic cycle (G3)time.phasefloatnullableEWHa[459/945]? H{alpha} EW of star (1)0.1nmspect.line.eqWidthfloatnullablee_EWHa[3/83]? EWHa uncertainty (1)0.1nmstat.errorfloatnullableEWHap[26/653]? H{alpha} EW of FOS4 (1)0.1nmspect.line.eqWidthfloatnullablee_EWHap[0.13/97.38]? EWHap uncertainty (1)0.1nmstat.errorfloatnullableEWHd[14/36]? H{delta} EW of star (2)0.1nmspect.line.eqWidthfloatnullablee_EWHd[0.01/3.02]? EWHd uncertainty (2)0.1nmstat.errorfloatnullableEWHdp[14.95/21.52]? H{delta} EW of FOS4 (2)0.1nmspect.line.eqWidthfloatnullablee_EWHdp[0.17/2.27]? EWHdp uncertainty (2)0.1nmstat.errorfloatnullable