J/A+A/672/A69ivo://CDS.VizieR/J/A+A/672/A69doi:10.26093/cds/vizier.36720069CDSRanaivomanana P.Johnston C.Groot P.J.Aerts C.Lees R.IJspeert L.,Bloemen S.Klein-Wolt M.Woudt P.Kording E.Le Poole R.Pieterse D.2024-11-06T20:03:44Z2023-03-30T10:11:12ZCDS support team

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

cds-question@unistra.frdwarf-starsvariable-starsphotometryvisible-astronomyColour-magnitude diagrams reveal a population of blue (hot) subluminous objects with respect to the main sequence. These hot subluminous stars are the result of evolutionary processes that require stars to expel their obscuring, hydrogen-rich envelopes to reveal the hot helium core. As such, these objects offer a direct window into the hearts of stars that are otherwise inaccessible to direct observation. We showcase MeerLICHT's capabilities of detecting faint hot subdwarfs and identifying the dominant frequency in the photometric variability of these compact hot stars, in comparison to their Gaia DR3 data. We hunt for oscillations as an essential ingredient for future asteroseismology to accurately probe their stellar interior. Comparative MeerLICHT and Gaia colour-magnitude diagrams are presented as a way to select hot subdwarfs from our sample. A dedicated frequency determination technique is developed and applied to the selected candidates to determine their dominant variability using time-series data from MeerLICHT and Gaia DR3. We explore the power of both datasets in determining the dominant frequency. Using the g-i colour, MeerLICHT offers a colour-magnitude diagram that is comparable in quality to that of Gaia DR3. The former, however, is more sensitive to fainter objects. The MeerLICHT colour-colour diagrams allow for the study of different stellar populations. The frequency analysis of MeerLICHT and Gaia DR3 data demonstrates the superiority of our MeerLICHT multi-colour photometry to estimate the dominant frequency compared to the sparse Gaia DR3 data. MeerLICHT's multiband photometry leads to the discovery of high-frequency faint subdwarfs. Continued observations tuned to asteroseismology will allow for mode identification using the method of amplitude ratios. Our MeerLICHT results are a proof-of-concept for the capacity of the BlackGEM instrument currently in commissioning at ESO's La Silla Observatory in Chile.2023A&A...672A..69Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/672/A69CatalogResearchIsServedByTAP 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/672/A69https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/672/A69http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/672/A69https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/672/A69https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/672/A69http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/672/A69GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/672/A69/tablea1 (A full list of the candidates with their derived periods)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/672/A69/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/672/A69/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/672/A69/tablea1?GETtext/xml+votable180.050000true0.08377-33.249930.0055555555555555565/8239 8263 8269 8274-8275 8278 8281 6/4255 16435 16444 16647 20742 22913 25634 33047 33051 33073 33089-33094 33104-33105 33120-33121 33123 33129 33136-33137 33187 33293-33295 33298 33304-33306 33316-33317 33319 33328 33330 33984 34493 34539 39829 43806 43825 43828 45420https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/672/A69?format=asciiOpticaldefaultJ/A+A/672/A69/tablea1A full list of the candidates with their derived periods_RA.icrsRight ascension (ICRS) at Epoch=J2016. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2016. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/610] Source identifiermeta.id;meta.mainintRA_ICRSRight ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainqmag? MeerLICHT q-band magnitudemagphot.mag;em.optfloatnullableumag? MeerLICHT u-band magnitudemagphot.mag;em.opt.Ufloatnullableimag? MeerLICHT i-band magnitudemagphot.mag;em.opt.IfloatnullableNqNumber of observations in the q-bandmeta.numberintNuNumber of observations in the u-bandmeta.numberintNiNumber of observations in the i-bandmeta.numberintPerDerived perioddtime.perioddoubleSNRSignal-to-noise ratiostat.snrintClass[0/2] Preliminary variability classification (1)src.classintGDR3Display the Gaia DR3 data (Gaia Collaboration, 2022, Cat. I/355)meta.ref.urlchar