J/AJ/152/1ivo://CDS.VizieR/J/AJ/152/1doi:10.26093/cds/vizier.51520001CDSKenyon S.J.Garcia M.R.2017-06-01T08:51:55Z2016-08-19T07:59:48ZCDS support team

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

cds-question@unistra.frspectroscopic-binary-starsradial-velocityWe analyze a roughly 20yr set of spectroscopic observations for the symbiotic binary EG And. Radial velocities derived from echelle spectra are best fit with a circular orbit having an orbital period of P=483.3+/-1.6 days and semi-amplitude K=7.34+/-0.07km/s. Combined with previous data, these observations rule out an elliptical orbit at the 10{sigma} level. Equivalent widths of HI Balmer emission lines and various absorption features vary in phase with the orbital period. Relative to the radius of the red giant primary, the apparent size of the H ii region is consistent with a model where a hot secondary star with effective temperature T_h_~75000K ionizes the wind from the red giant.2016AJ....152....1Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/152/1CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/sb : 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix+ 2004-2014)B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)J/AN/333/242 : Recent photometry of symbiotic stars (Skopal+, 2012)J/PASP/122/35 : Symbiotic stars on Asiago plates (Jurdana-Sepic+, 2010)J/A+AS/146/407 : Symbiotic stars catalogue (Belczynski+, 2000)J/A+A/318/53 : UBV photometry of EG And (Skopal 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/152/1https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/152/1http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/152/1https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/152/1https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/152/1http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/152/1GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/152/1/table1EG And radial velocity datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJD[45243.7/50438.6] Modified Julian Date (JD-2400000)dtime.epochdoublePhase[0/1] Orbital phase (1)time.phasefloatRV[-103.18/-86.95] Radial velocity (v_r_)km/sphys.veloc;pos.heliocentricfloatO-C[-2/1.61] The (O-C) residualkm/sstat.fit.residual;stat.fit.omcfloat