J/AJ/149/30ivo://CDS.VizieR/J/AJ/149/30doi:10.26093/cds/vizier.51490030CDSSamec R.G.Koenke S.S.Faulkner D.R.2017-07-04T07:09:15Z2015-02-03T14:41:32ZCDS support team

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

cds-question@unistra.freclipsing-binary-starsinfrared-photometryvisible-astronomybroad-band-photometryA 2012 follow up to the analysis of 2009 observations is presented for the very short period (~0.43days) precontact W UMa binary (PCWB) V1001 Cassiopeia. Its short period, similar to the majority of W UMa binaries, and its distinct EA light curve make it a very rare and interesting system for continuing photometric investigation. Previous photometric VRI standard magnitudes give a K4 spectral type. Our solutions of light curves separated by some three years give approximately the same physical parameters. However, the spots have radically changed in temperature, area, and position. While only one dark spot was used to model the first curves, two hot spots are now needed. This affects the overall shape of the light curve, especially in the secondary eclipses in B and V. Additional eclipse timings now show that the orbital period is changing. We conclude that spots are very active on this solar-type dwarf system and that it may mimic its larger cousins, the RS CVn binaries. The conclusion is that analysis now needs to be directed at the continuous time evolution of PCWBs.2015AJ....149...30Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/149/30CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)J/AJ/142/117 : UBVrcIc differential photometry of V1853 Ori (Samec+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/149/30https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/149/30http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/149/30https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/149/30https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/149/30http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/149/30GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/149/30/table1Photometry of V1001 CasrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBandObserved band (Johnson-Cousins BVRI)instr.bandpasscharDmagDelta magnitude in filter (in the sense of variable minus comparison star)magphot.mag;arith.difffloatHJDHeliocentric Julian Date (HJD-2456190)dtime.epochfloat