J/A+A/461/183ivo://CDS.VizieR/J/A+A/461/183doi:10.26093/cds/vizier.34610183CDSGrankin K.N.Melnikov S.Y.Bouvier J.Herbst W.Shevchenko V.S.2007-02-07T10:11:13Z2007-02-07T11:10:09ZCDS support team

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

cds-question@unistra.frpre-main-sequence-starsinfrared-photometryvisible-astronomybroad-band-photometryWe report the results of a study the long term variability of Classical T Tauri stars (CTTS) over up to 20 years, characterize it from a set of statistical parameters and discuss its origin. We characterize the long term photometric variations of 49 CTTs with sufficient data for allowing a robust statistical analysis and propose an empirical classification scheme. Several patterns of long term photometric variability are identified. The most common pattern, exhibited by a group of 15 stars which includes T Tau itself, consists of low level variability (with V-amplitude less than 0.4mag) with no significant changes occurring from season to season over many years. A related subgroup of 22 stars exhibit a similar stable long term variability pattern, though with larger amplitudes (up to 1.6mag). Besides these representative groups, we identify three smaller groups of 3-5 stars each of which have distinctive photometric properties. The long term variability of most CTTS is fairly stable and merely reflects shorter term variability due to cold and hot surface spots. Only a small fraction of CTTS undergo significant brightness changes on the long term (months, years), which probably arise from slowly varying circumstellar extinction.2007A&A...461..183Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/461/183CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/299/89 : COYOTES II (Bouvier+, 1995)J/A+A/310/143 : Variability of classical T Tauri stars (Fernandez+, 1996)J/A+AS/120/267 : T Tauri stars UBrHalphaz photometry (Osterloh+ 1996)J/A+AS/128/561 : UBVRI photometry of southern T Tauri stars (Batalha+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/461/183https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/461/183http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/461/183https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/461/183https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/461/183http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/461/183GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/461/183/stars (List of the stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/461/183/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/461/183/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/461/183/stars?GETtext/xml+votable180.050000true83.792917-5.7761110.0055555555555555565/292 6/342 1029 1031 1048 1050-1051 1073-1075 1081 1083 1111 1114-1115 1124 1136 1156 3038 13786 13981 14306 14700 15363 15368 15409 16129 21435-21436 21438 22805 23548-23549 23551 23646 23704 23727 23738-23739 23970 24201 29201 30741 42977 42981 42992 42994 44317 44379 47828https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/461/183?format=asciiOpticalInfrareddefaultJ/A+A/461/183/starsList of the starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSimbad namemeta.id;meta.maincharRAJ2000Simbad Hour of Right Ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Simbad Degree of Declination (J2000.0)pos.eq.dec;meta.mainBmag? Simbad B band magnitudemagphot.mag;em.opt.BfloatnullableVmag? Simbad V band magnitudemagphot.mag;em.opt.VfloatnullableSpTypeSimbad MK spectral typesrc.spTypecharFileNameData file name, in "phot" subdirectorymeta.id;meta.filechar