J/MNRAS/478/5091ivo://CDS.VizieR/J/MNRAS/478/5091doi:10.26093/cds/vizier.74785091CDSFroebrich D.Campbell-White J.Scholz A.Eisloffel J.Zegmott T.,Billington S.J.Donohoe J.Makin S.V.Hibbert R.Newport R.J.,Pickard R.Quinn N.Rodda T.Piehler G.Shelley M.Parkinson S.,Wiersema K.Walton I.2024-08-18T20:20:19Z2021-12-10T14:52:49ZCDS support team

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

cds-question@unistra.frvariable-starsinfrared-photometryvisible-astronomyphotometryVariability in young stellar objects (YSOs) is one of their primary characteristics. Long-term, multifilter, high-cadence monitoring of large YSO samples is the key to understand the partly unusual light curves that many of these objects show. Here we introduce and present the first results of the HOYS-CAPS citizen science project that aims to perform such monitoring for nearby (d<1kpc) and young (age<10Myr) clusters and star-forming regions, visible from the northern hemisphere, with small telescopes. We have identified and characterized 466 variable (413 confirmed young) stars in eight young, nearby clusters. All sources vary by at least 0.2mag in V, have been observed at least 15 times in V, R, and I in the same night over a period of about 2 yr, and have a Stetson index of larger than 1. This is one of the largest samples of variable YSOs observed over such a time span and cadence in multiple filters. About two-thirds of our sample are classical T-Tauri stars, while the rest are objects with depleted or transition discs. Objects characterized as bursters show by far the highest variability. Dippers and objects whose variability is dominated by occultations from normal interstellar dust or dust with larger grains (or opaque material) have smaller amplitudes. We have established a hierarchical clustering algorithm based on the light-curve properties that allows the identification of the YSOs with the most unusual behaviour and to group sources with similar properties. We discuss in detail the light curves of the unusual objects V2492 Cyg, V350 Cep, and 2MASS J21383981+5708470.2018MNRAS.478.5091Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/478/5091CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/478/5091https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/478/5091http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/478/5091https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/478/5091https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/478/5091http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/478/5091GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/478/5091/tablea1 (Individual properties of all stars investigated in the paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/478/5091/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/478/5091/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/478/5091/tablea1?GETtext/xml+votable180.050000true52.045916931.291470.0055555555555555566/859 862 1539 14029 14031 14040 14042 14685 14687 15368 15370 15476 15478-15479 15484 15759 15781 22249 22252 23636-23637 23639https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/478/5091?format=asciiOpticalInfrareddefaultJ/MNRAS/478/5091/tablea1Individual properties of all stars investigated in the paperSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharRegionRegionmeta.notecharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainNvarNumber of points in the lightcurve used to determine the slope alpha in the V vs V-I diagrammeta.numberintalphaSlope of a linear fit in the V vs V-Idegstat.fit.paramfloatrmsrms of the datapoints from the fitmagphot.mag;meta.modelledfloatMAsymmetry indexsrc.morph.paramfloatSStetson indexmeta.code;spect.indexfloatGGroup in the dendrogram the source is associated withmeta.idintDVRange of magnitude in V band light curvemagsrc.var.amplitudefloate_Vrms of the V band light curvemagstat.error;pos.cartesian.yfloatDRRange of magnitude in R band light curvemagsrc.var.amplitudefloate_Rrms of the R band light curvemagstat.errorfloatDIRange of magnitude in I band light curvemagsrc.var.amplitudefloate_Irms of the I band light curvemagstat.errorfloat