J/MNRAS/521/1700ivo://CDS.VizieR/J/MNRAS/521/1700doi:10.26093/cds/vizier.75211700CDSMoulton T.Hodgkin S.T.Smith G.D.Briegal J.T.Gillen E.Acton J.S.,Battley M.P.Burleigh M.R.Casewell S.L.Gill S.Goad M.R.,Henderson B.A.Kendall A.Ramsay G.Tilbrook R.H.Wheatley P.J.2024-08-22T20:17:06Z2023-05-23T10:22:12ZCDS support team

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

cds-question@unistra.frmolecular-cloudspre-main-sequence-starsvariable-starsinfrared-photometryvisible-astronomyThe dipper is a novel class of young stellar object associated with large drops in flux on the order of 10-50 per cent lasting for hours to days. Too significant to arise from intrinsic stellar variability, these flux drops are currently attributed to disk warps, accretion streams, and/or transiting circumstellar dust. Dippers have been previously studied in young star forming regions including the Orion Complex. Using Next Generation Transit Survey (NGTS) data, we identified variable stars from their lightcurves. We then applied a machine learning random forest classifier for the identification of new dipper stars in Orion using previous variable classifications as a training set. We discover 120 new dippers, of which 83 are known members of the Complex. We also investigated the occurrence rate of disks in our targets, again using a machine learning approach. We find that all dippers have disks, and most of these are full disks. We use dipper periodicity and model-derived stellar masses to identify the orbital distance to the inner disk edge for dipper objects, confirming that dipper stars exhibit strongly extended sublimation radii, adding weight to arguments that the inner disk edge is further out than predicted by simple models. Finally, we determine a dipper fraction (the fraction of stars with disks which are dippers) for known members of 27.8+/-2.9 per cent. Our findings represent the largest population of dippers identified in a single cluster to date.2023MNRAS.521.1700Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/521/1700CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/521/1700https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/521/1700http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/521/1700https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/521/1700https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/521/1700http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/521/1700GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/521/1700/ngtsvar (All variable NGTS sources analyzed in the paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/521/1700/ngtsvar?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/521/1700/ngtsvar?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/521/1700/ngtsvar?GETtext/xml+votable180.050000true85.0576093191652-4.00350342917190.0055555555555555565/5359 5701 6/21430-21431 21433-21435 21480 21482-21483 22801 22813 22848-228508.157980699529898e-21 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/521/1700?format=asciiOpticalInfrareddefaultJ/MNRAS/521/1700/ngtsvarAll variable NGTS sources analyzed in the paperrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[0/2099] Running numbermeta.idintNGTS[34/35795] NGTS identification numbermeta.id;meta.mainintRAJ2000Right Ascension from NGTS (J2000)degpos.eq.ra;meta.mainDEJ2000Declination from NGTS (J2000)degpos.eq.dec;meta.mainmagmeanMean NGTS magnitude (MEAN-MAG)magphot.mag;em.optdoublemagrmsNGTS magnitude RMS (MAG-RMS)magstat.errordoubleFluxAsymMFlux asymmetry of the lightcurve (M statistic) (Flux-Asymmetry-M)src.var.amplitudedoubleLSperiodLomb-Scargle period (LS-period)dtime.perioddoubleLSpdgmstddevStandard deviation of the Lomb-Scargle periodogram (LS-pdgm-std-dev)stat.stdevdoubleLSmaxPowerMaximum power of the Lomb-Scargle periodogram (LS-MAX-Power)src.var.indexdoublestddevStandard deviation of the lightcurve (std-dev)stat.stdevdoubleAperQAperiodicity of the lightcurve (Q statistic) (Aperiodicity-Q)src.var.indexdoubleamp9010Difference between the 90th and 10th percentile of the lightcurve (amp9010)src.var.amplitudedoubleMADMedian absolute deviation of the lightcurve (MAD)stat.stdevdoubledtavDifference between the mean and the median of the lightcurve (dtav)src.var.amplitudedoubleBLSPerBox least squares period (BLS-Period)dtime.perioddoubleBLSmaxPowerMaximum power of the BLS periodogram (BLS-Max-power)src.var.indexdoubleBLSdurBLS duration of the transit (BLS-duration)dtime.durationdoubleBLSdepthBLS depth of the transit (BLS-depth)magphys.absorption.opticalDepthdoubleK-W2K-W2 colour indexmagphot.color;em.IR;em.IRdoubleGmag? Gaia G magnitudemagphot.mag;em.optdoublenullableBPmag? Gaia BP magnitudemagphot.mag;em.opt.BdoublenullableRPmag? Gaia RP magnitudemagphot.mag;em.opt.RdoublenullableJmag? 2MASS J magnitudemagphot.mag;em.IR.JdoublenullableHmag? 2MASS H magnitudemagphot.mag;em.IR.HdoublenullableKmag? 2MASS K magnitudemagphot.mag;em.IR.KdoublenullableW1mag? WISE W1 magnitudemagphot.mag;em.IR.3-4umdoublenullableW2mag? WISE W2 magnitudemagphot.mag;em.IR.4-8umdoublenullableW3mag? WISE W3 magnitudemagphot.flux.density;em.IR.8-15umdoublenullableW4mag? WISE W4 magnitudemagphot.flux.density;em.IR.15-30umdoublenullableP-Prob? Periodic probability (P-Probability)stat.fit.goodnessdoublenullableD-Prob? Dipper Probability (D-Probability)stat.fit.goodnessdoublenullableEB-Prob? Eclipsing Binary probability (EB-Probability)stat.fit.goodnessdoublenullableClassAssigned Class (D, P or EB) (1)src.classcharTIC? TIC identification numbermeta.idnullabler_Class? Source of training set classification from the literature (Original-Classification-Source)meta.ref;pos.framechar