J/MNRAS/501/5927ivo://CDS.VizieR/J/MNRAS/501/5927doi:10.26093/cds/vizier/bg-fn-5s7CDSAnusha R.Mathew B.Shridharan B.Arun R.Nidhi S.Banerjee G.,Kartha S.S.Paul K.T.Bhattacharyya S.2026-08-03T07:31:00Z2023-11-15T09:47:02ZCDS support team

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

cds-question@unistra.fremission-line-starsmilky-way-galaxyextinctionstellar-spectral-typesvisible-astronomyspectroscopyinfrared-astronomyWe report the first systematic study to identify and characterize a sample of classical Ae stars in the Galaxy. The spectra of these stars were retrieved from the A-star catalogue using the Large sky Area Multi-Object fibre Spectroscopic Telescope (LAMOST) survey. We identified the emission-line stars in this catalogue from which 159 are confirmed as classical Ae stars. This increases the sample of known classical Ae stars by about nine times from the previously identified 21 stars. The evolutionary phase of classical Ae stars in this study is confirmed from the relatively small mid- and far-infrared excess and from their location in the optical colour-magnitude diagram. We estimated the spectral type using MILES spectral templates and identified classical Ae stars beyond A3, for the first time. The prominent emission lines in the spectra within the wavelength range 3700-9000{AA} are identified and compared with the features present in classical Be stars. The H{alpha} emission strength of the stars in our sample show a steady decrease from late-B type to Ae stars, suggesting that the disc size may be dependent on the spectral type. Interestingly, we noticed emission lines of FeII, OI, and Paschen series in the spectrum of some classical Ae stars. These lines are supposed to fade out by late B-type and should not be present in Ae stars. Further studies, including spectra with better resolution, is needed to correlate these results with the rotation rates of classical Ae stars.2021MNRAS.501.5927Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/501/5927CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/164 : LAMOST DR5 catalogs (Luo+, 2019)II/336 : AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/501/5927https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/501/5927http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/501/5927https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/501/5927https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/501/5927http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/501/5927GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/501/5927/table2 (List of the classical Ae stars identified from this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/501/5927/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/501/5927/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/501/5927/table2?GETtext/xml+votable180.050000true4.426541745.74844440.0055555555555555566/798 1046 1149 1186 1267 1292 1302 1365 1369 1391 1423 1426 1429 1431-1432 1445 1447 1451-1452 1454 1461 1471 1475 1486 1510 1512 1584 1625 1630 1650 1653 1739 1756 1784 1789 1821 1826 1829 1888 1892 1928-1929 1943 2081 2131 2629 2743 2865 2924 2967 3009 3136 3155 3166 3170 3191 3197 3247 3601 4293 4768 5403 5459 6177 6280 6358 6363 6670 6827 6896 7066 7120 7137 10073 13048 14135 14433 14794 14955 21497 21786 21795 21967 21998 22078 22211 22215-22216 22221 22230 22234 22236 22241 22256 22261 22271 22421 23295 23650 23664 23673 23736 23740 23773 23809 23813 23815 23819 23862 23874 23907 23911 23919 23941 23954 23956 23960-23961 24008 24128 24132 24165 24181 24257 24264 24275 24315 24326 24335 24363-24364 24368 24371 24382 24393 24397 24412 24468 24471 24473 24478 24497 24499 24504 24506 24513 24517 24568 24574 27239 31562 32276 324683.322582951404819e-19 4.920466254354166e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/501/5927?format=asciiOpticalInfrareddefaultJ/MNRAS/501/5927/table2List of the classical Ae stars identified from this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/159] Internal identifiermeta.idintNameLAMOST designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharAvVisual extinction from Green et al. (2019ApJ...887...93G)magphys.absorptionfloatH-K0Extinction corrected 2MASS colormagphot.color;em.IR.H;em.IR.KfloatSpTypeEEstimated spectral type obtained from template matching with MILES library spectrasrc.spTypecharSpTypeLSpectral type given by LAMOSTsrc.spTypecharBmag? B-band magnitude from Henden et al. (2015AAS...22533616H, Cat. II/336)magphot.mag;em.opt.BfloatnullableVmag? V-band magnitude from Henden et al. (2015AAS...22533616H, Cat. II/336)magphot.mag;em.opt.Vfloatnullablen(K-W2)Spectral index from 2MASS Ks to WISE W2 calculated from the spectral energy distributionspect.indexfloatDateObservation datetime.epoch;obsEWHa? H{alpha} equivalent width corrected for underlying photospheric absorption0.1nmspect.line.eqWidthfloatnullableObsIDLAMOST unique spectra ID (1)meta.idlongFeaturesOther spectral features present (2)meta.note_RAPosition from LAMOST designation (right ascension part)degpos.eq.ra;meta.main_DEPosition from LAMOST designation (declination part)degpos.eq.dec;meta.main