J/MNRAS/480/488ivo://CDS.VizieR/J/MNRAS/480/488doi:10.26093/cds/vizier.74800488CDSIglesias D.Bayo A.Olofsson J.Wahhaj Z.Eiroa C.Montesinos B.,Rebollido I.Smoker J.Sbordone L.Schreiber M.R.Henning T.2024-08-18T20:21:27Z2022-05-17T13:32:00ZCDS support team

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

cds-question@unistra.frexoplanetscometsdiffuse-molecular-cloudsDebris discs are second-generation dusty discs thought to be devoid of gas. However, this idea has been challenged in the last years by gas detections in some systems. We compiled a database of 301 debris discs and collected high-resolution optical spectra for ~77 per cent of them. From the analysis of these data we identified a group of 23 debris discs presenting several absorption features superimposed to the photospheric CaII and NaI doublets. These absorptions could be due to circumstellar material or interstellar clouds. In order to discriminate between the two scenarios, we characterized each feature in terms of its radial velocity, equivalent width, and column density. Additionally, we searched in the literature for local clouds in the line of sight of the stars, and looked for the presence of similar absorption features in nearby stars. Our study concludes that while all the objects present interstellar absorptions in their spectra, three objects show features more compatible with circumstellar origin: HD 110058 presents a stable circumstellar absorption, while HR 4796 and c Aql present variable absorption features likely due to exocometary activity. The minute-scale variability we detect towards c Aql is the shortest of this kind detected so far. The detection of circumstellar features in these objects is consistent with their near edge-on inclinations. We also provide evidence challenging previous claims of circumstellar gas detections for HR 6507. Given the properties of the sample, we speculate that transient gaseous events must be a common phenomenon among debris discs.2018MNRAS.480..488Ihttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/480/488CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/480/488https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/480/488http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/480/488https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/480/488https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/480/488http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/480/488GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/480/488/table4 (Stellar parameters determined from the synthetic model fitting and radial velocity estimates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/488/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/488/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/488/table4?GETtext/xml+votable180.050000true8.1829392-63.03150060.0055555555555555566/19817 21388 21528 22859 22884 24796 30467 31078 31281 33547 34415 34823 37012 37231 37816 39501 42742 43017 43232 43372 43540 43677https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/480/488?format=asciidefaultJ/MNRAS/480/488/table4Stellar parameters determined from the synthetic model fitting and radial velocity estimatesSimbadNameSimbad column added by the CDSmeta.idcharnullableNameStar namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintvsini? Rotational velocity (1)km/sphys.veloc.rotatintnullableRVRadial velocitykm/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorkm/sstat.errorfloatf_RV? Flag on RV (2)meta.codecharTeff(CaIIK)? Effective temperature (3)Kphys.temperature.effectiveintnullablelogg? Surface gravitylog(cm.s**-2)phys.gravityfloatnullablee_logg? Surface gravity error (4)log(cm.s**-2)stat.errorfloatnullablef_logg? Flag on logg (5)meta.codechar[Fe/H]? Metallicityphys.abund.Zfloatnullablee_[Fe/H]? Metallicity error (4)stat.error;phys.abund.Fefloatnullablef_[Fe/H]? Flag on metallicity (5)meta.codechar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/MNRAS/480/488/table6Absorption feature parametersHRVNaID2? Heliocentric radial velocity for the NaI D2 line (3)km/sspect.dopplerVeloc;pos.heliocentricfloatnullablelogNNaID2? NaI D2 Apparent column density (4)log(cm**-2)phys.columnDensityfloatnullableEWNaID2? Equivalent width of the features present in the NaI D2 line (4)0.0001nmspect.line.eqWidthfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar Namemeta.id;meta.maincharHRVCaIIK? Heliocentric radial velocity for the CaII K line (1)km/sspect.dopplerVeloc;pos.heliocentricfloatnullablelogNCaIIK? CaII K Apparent column density (2)log(cm**-2)phys.columnDensityfloatnullableEWCaIIK? Equivalent width of the features present in the CaII K line (2)0.0001nmspect.line.eqWidthfloatnullableHRVCaIIH? Heliocentric radial velocity for the CaII H line (1)km/sspect.dopplerVeloc;pos.heliocentricfloatnullablelogNCAIIH? CaII H Apparent column density (2)log(cm**-2)phys.columnDensityfloatnullableEWCaIIH? Equivalent width of the features present in the CaII H line (2)0.0001nmspect.line.eqWidthfloatnullableHRVNaID1? Heliocentric radial velocity for the NaI D1 line (3)km/sspect.dopplerVeloc;pos.heliocentricfloatnullablelogNNaID1? NaI D1 Apparent column density (4)log(cm**-2)phys.columnDensityfloatnullableEWNaID1? Equivalent width of the features present in the NaI D1 line (4)0.0001nmspect.line.eqWidthfloatnullableJ/MNRAS/480/488/table8Absorption components and their mean radial velocity, CaII/NaI density ratio, absorption feature detection in a nearby star, and proposed originrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRVRadial velocity of starkm/sphys.veloc;pos.heliocentricfloate_RVRV errorkm/sstat.errorfloatCloud? Traversing cloud namemeta.id.parentcharCloudRV? Radial velocity of cloudkm/sphys.veloc;pos.heliocentricfloatnullablee_CloudRV? CloudRV errorkm/sstat.errorfloatnullableFeature? Matching feature (1)meta.codecharFeatureRVRadial velocity of featurekm/sphys.veloc;pos.heliocentricfloatl_NCaII/NNaILimit flag on CaII/NaI density ratiometa.code.errorcharNCaII/NNaI? CaII/NaI density ratiometa.crypticfloatnullableNearbyStar? Nearby star (2)meta.codecharOriginProposed origin (3)meta.codecharJ/MNRAS/480/488/tablec1All nearby stars used in the analysis per each object of science, their number of spectra, instrument, and ESO programme IDrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (1)meta.id;meta.maincharNBSnameNearby star namemeta.idcharNSpecNumber of spectrameta.numberintInstInstrumentmeta.id;instrcharPIDESO programme IDmeta.id;obschar