J/A+A/693/A268ivo://CDS.VizieR/J/A+A/693/A268doi:10.26093/cds/vizier.36930268CDSRanaivomanana P.Uzundag M.Johnston C.Groot P.J.Kupfer T.Aerts C.2025-03-03T20:01:26Z2025-01-27T09:22:15ZCDS support team

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

cds-question@unistra.frvariable-starssubdwarf-starsorbitsvisible-astronomyHot sub-luminous stars represent a population of stripped and evolved red giants located at the Extreme Horizontal Branch (EHB). Since they exhibit a wide range of variability due to pulsations or binary interactions, unveiling their intrinsic and extrinsic variability is crucial for understanding the physical processes responsible for their formation. In the Hertzsprung-Russell diagram, they overlap with interacting binaries such as Cataclysmic Variables (CVs). By leveraging cutting-edge clustering algorithm tools, we investigate the variability of 1,576 hot subdwarf variable candidates using comprehensive data from Gaia DR3 multi-epoch photometry and Transiting Exoplanet Survey Satellite (TESS) observations. We present a novel approach that utilises the t-distributed stochastic neighbor embedding (t-SNE) and the Uniform Manifold Approximation and Projection (UMAP) dimensionality reduction algorithms to facilitate the identification and classification of different populations of variable hot subdwarfs and Cataclysmic Variables in a large dataset. In addition to the publicly available Gaia time-series statistics table, we adopt extra statistical features that enhance the performance of the algorithms. The clustering results lead to the identification of 85 new hot subdwarf variables based on Gaia and TESS lightcurves and 108 new variables based on Gaia lightcurves alone, including reflection-effect systems, HW Vir, ellipsoidal variables, and high-amplitude pulsating variables. A significant number of known Cataclysmic Variables (140) distinctively cluster in the 2-D feature space among an additional 152 objects that we consider new Cataclysmic Variable candidates. This study paves the way for more efficient and comprehensive analyses of stellar variability from both ground and space-based observations, as well as the application of machine learning classifications of variable star candidates in large surveys.2025A&A...693A.268Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/693/A268CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/693/A268https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/693/A268http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/693/A268https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/693/A268https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/693/A268http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/693/A268GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/693/A268/tablea4 (Variability of 63 confirmed hot subdwarfs identified from Gaia and TESS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A268/tablea4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A268/tablea4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A268/tablea4?GETtext/xml+votable180.050000true210.48072-75.226080.005555555555555556Cone search capability for table J/A+A/693/A268/tablea5 (Variability of 78 candidate hot subdwarfs identified from Gaia and TESS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A268/tablea5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A268/tablea5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A268/tablea5?GETtext/xml+votable180.050000true128.4624-82.183320.005555555555555556Cone search capability for table J/A+A/693/A268/tablea6 (New variables (134) identified from candidate hot subdwarfs with Gaia lightcurves alone)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A268/tablea6?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A268/tablea6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A268/tablea6?GETtext/xml+votable180.050000true156.23465-79.524870.005555555555555556Cone search capability for table J/A+A/693/A268/tablea7 (New variables (15) identified from known hot subdwarfs with Gaia lightcurves alone)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A268/tablea7?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A268/tablea7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A268/tablea7?GETtext/xml+votable180.050000true179.10219-62.295060.005555555555555556Cone search capability for table J/A+A/693/A268/tablea8 (List of 140 known CVs from Cluster 2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A268/tablea8?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A268/tablea8?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A268/tablea8?GETtext/xml+votable180.050000true76.97458-79.856230.005555555555555556Cone search capability for table J/A+A/693/A268/tablea9 (List of 152 candidate CVs from Cluster 2 identified in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A268/tablea9?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A268/tablea9?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A268/tablea9?GETtext/xml+votable180.050000true173.78942-88.599870.0055555555555555566/557 1109 1559 1685 1810 1900 2033 2073 2154 2544 2591 2674 2686 2715 2717 2731 2753 2766 2781 2783 2793 2806 2867 2906 3091 3139 3224 3440 3541 3620 3815 3835 3923 4011 4020 4040 4052 4367 4757 5650 5809 5883 6075 6247 6254 6456 6637 6784 6817 6860 6864 6902 6973 7007 7036 7046 7072 7100 7306 7577 7812 7830 7906 8006 8042 8044 8088 8111 8173 8474 8596 8977 9425 9578 9589 9672 9774-9775 9998 10024 10226 10799 10958 11084 11485 12048 12164 12186 12334 12411 12537 12556 12568 12804 12810 12835 12844 12876 12896 12911 12927 12941 13002 13012 13015 13064 13071 13084 13092 13097 13108 13245 13252 13255 13258 13264 13269 13283 13285 13358 13417 13474 13477 13497 13542 13601 13646 13682 13819 13896 13917 13988 14004 14016 14033 14056 14099 14109 14121 14132 14171 14175 14184 14212 14214 14217 14232-14233 14241 14392 14430 14439 14476 14485 14501 14535 14542 14573 14578 14591 14624 14700 14731-14732 14735 14761 14775 14779 14781 14835 14844 14846 14867 14943 14947 14964 14972 15001 15014 15042 15053 15106-15107 15110 15122 15163 15324 15340 15364 15491 15500 15504 15523 15531 15567 15603 15693 15770 15784 15855 15894 16053 16076 16214-16215 16252 16280 16550 18881 19180 19950 19984 20002 20221 20314 20351 20410 20522 20553 20581 20589 20592 20673 20687 20694 20719 20737 20755 20765 20798 20812 20868 20891 20911 20943 21041 21099 21196 21245 21269 21285 21366 21476 21504 21508 21517 21534 21544 21567 21605 21607 21613 21629 21696 21756 21809 21907-21908 21991 21994 22280 22296 22360 22363 22804 22813 22863 22890 23510 23726 23807 23982 24377 24466 24471 24522 24534 24636 24675 24819 24964 26112 26416 26609 28047 28637 28678 28706 28721 28935 29066 29222 29365 29386 29728 29808 30001 30095 30112 30140 30168 30173 30483 30490 30519 30570 30574 30662 30684 31065 31684 31740 31765 31781 31887 31967 32015 32025 32034 32046 32131 32212 32222 32409 32537 32551 32581 32584 32666 32845 33097 33491 33621 33822 33856 33866 34250 34336 35025 35181 35752 36180 36307 36865 36920 36941-36942 36987 37067 37120 37163 37203 37244 37288 37319 37322 37325 37328 37356 37420 37432 37535 37578-37579 37587 37589 37601 37633 37653-37654 37659-37660 37679 37694 37764 37903 37905 37907 37910 37954 37994 38000 38006 38041 38085 38105 38112 38128 38149 38164 38188 38267 38296 38301 38323 38483 38507 38519 38579 38587 38613 38656 38694 38721 38727 38745 38804 38857 38980 39033 39037 39045-39046 39057 39063 39077 39189 39195 39209 39236 39272 39314 39320 39371 39410 39453 39478 39495 39510 39520 39545 39591 39625 39671 39678 39696 39720 39738 39750-39751 39767 39803 39836 39873-39874 39902 39930-39931 39933 39946 39950 40013 40093 40122 40227 40301 40463 40485 40514 40568 40571 40576 40587 40589 40617 40631 40686 40883 40897 40916 41119 41142 41182 41192 41204 41244 41251 41259 41263 41270 41278 41350 41383 41423 41452 41461 41514 41564 41611 41667 41685 41707 41710 41724 41727 41768 41841 41936 41940 41972 41978 42004 42034 42059 42064 42078 42106 42128 42156 42241 42311 42417 42531 42536 42633 42794 42838 42907 43039 43050 43126 43156 43168 43175 43194 43226 43232 43268 43333 43542 43659 43695 43760 43763 43929 44026 44036 44311 44323 44439 45143 45226 45234 45487 45681 45817 45927 46109 46182 46220 46378 46430 46458 46692 46727 46990 47063 47106 47272 47293 47425 47437 47498 47528 47645 47657 47731 47737 47777 48212 48215 48348 48635 48662 48687 48765 48769 48842 48944 48972https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/693/A268?format=asciiOpticaldefaultJ/A+A/693/A268/tablea4Variability of 63 confirmed hot subdwarfs identified from Gaia and TESSGaiaDR3Gaia DR3 source IDmeta.id;meta.mainRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainPerGGaia G-band perioddtime.perioddoublee_PerGGaia G-band period uncertainty0.01dstat.errordoublePerTTESS perioddtime.perioddoublee_PerTTESS period uncertainty0.01dstat.errordoubleRefReference (G1)meta.ref;pos.framecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSimbadSimbad column added by the CDSmeta.ref.urlcharTypeVariability typemeta.notecharJ/A+A/693/A268/tablea5Variability of 78 candidate hot subdwarfs identified from Gaia and TESSRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainPerGGaia G-band perioddtime.perioddoublee_PerGGaia G-band period uncertainty0.01dstat.errordoublePerTTESS perioddtime.perioddoublee_PerTTESS period uncertainty0.01dstat.errordoubleTypeVariability typemeta.notecharRefReference (g1)meta.ref;pos.framecharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 source IDmeta.id;meta.mainJ/A+A/693/A268/tablea6New variables (134) identified from candidate hot subdwarfs with Gaia lightcurves alonerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSimbadSimbad column added by the CDSmeta.ref.urlcharGaiaDR3Gaia DR3 source IDmeta.id;meta.mainRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainPerGGaia G-band perioddtime.perioddoublee_PerGGaia G-band period uncertainty0.01dstat.errordoubleTypeVariability typemeta.notecharJ/A+A/693/A268/tablea7New variables (15) identified from known hot subdwarfs with Gaia lightcurves alonee_PerGGaia G-band period uncertainty0.01dstat.errordoubleTypeVariability typemeta.notecharRefReference (G1)meta.ref;pos.framecharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 source IDmeta.id;meta.mainRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainPerGGaia G-band perioddtime.perioddoubleJ/A+A/693/A268/tablea8List of 140 known CVs from Cluster 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 source IDmeta.id;meta.mainRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharTypeCV typemeta.code;src.varcharPerT? TESS perioddtime.perioddoublenullablee_PerT? TESS period uncertainty0.01dstat.errordoublenullablePorb? Orbital period from the literaturedtime.perioddoublenullableRefReference (G1)meta.ref;pos.framecharJ/A+A/693/A268/tablea9List of 152 candidate CVs from Cluster 2 identified in this workSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 source IDmeta.id;meta.mainRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainPerT? TESS perioddtime.perioddoublenullablee_PerT? TESS period uncertainty0.01dstat.errordoublenullable