J/MNRAS/448/1118ivo://CDS.VizieR/J/MNRAS/448/1118doi:10.26093/cds/vizier.74481118CDSGozdziewski K.Slowikowska A.Dimitrov D.Krzeszowski K.Zejmo M.,Kanbach G.Burwitz V.Rau A.Irawati P.Richichi A.Gawronski M.,Nowak G.Nasiroglu I.Kubicki D.2024-08-14T20:19:54Z2017-11-27T13:56:28ZCDS support team

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

cds-question@unistra.frmultiple-starssolar-system-planetsvariable-starsephemeridesWe study the mid-egress eclipse timing data gathered for the cataclysmic binary HU Aquarii during the years 1993-2014. The (O-C) residuals were previously attributed to a single ~7 Jupiter mass companion in ~5 AU orbit or to a stable two-planet system with an unconstrained outermost orbit. We present 22 new observations gathered between 2011 June and 2014 July with four instruments around the world. They reveal a systematic deviation of ~60-120 s from the older ephemeris. We re-analyse the whole set of the timing data available. Our results provide an erratum to the previous HU Aqr planetary models, indicating that the hypothesis for a third and fourth body in this system is uncertain. The dynamical stability criterion and a particular geometry of orbits rule out coplanar two-planet configurations. A putative HU Aqr planetary system may be more complex, e.g. highly non-coplanar. Indeed, we found examples of three-planet configurations with the middle planet in a retrograde orbit, which are stable for at least 1 Gyr, and consistent with the observations. The (O-C) may be also driven by oscillations of the gravitational quadrupole moment of the secondary, as predicted by the Lanza et al. modification of the Applegate mechanism. Further systematic, long-term monitoring of HU Aqr is required to interpret the (O-C) residuals.2015MNRAS.448.1118Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/448/1118CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/123 : Catalog of Cataclysmic Variables (Downes+ 2001-2006)J/AJ/147/45 : Kepler mission. IV. Eclipse times for close binarieshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/448/1118https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/448/1118http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/448/1118https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/448/1118https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/448/1118http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/448/1118GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/MNRAS/448/1118/tablea1Mid-egress moments available in the literature.recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCycle[0/89340] Cycle number (1)meta.id;meta.mainintMJDThe moment of the mid-egress in Modified Julian Datedtime.epochdoublee_MJDUncertainty in MJDdstat.error;time.epochdoubleInstInstrument used for the observationinstr.setupcharr_Inst[1/6] Instrument reference (2)meta.ref;pos.frameint