J/A+A/645/A34ivo://CDS.VizieR/J/A+A/645/A34doi:10.26093/cds/vizier.36450034CDSPaunzen E.Hummerich S.Bernhard K.2024-07-16T20:01:39Z2021-03-04T10:25:10ZCDS support team

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

cds-question@unistra.frvariable-starspeculiar-variable-starsvisible-astronomytrigonometric-parallaxapparent-magnitudeThe present work presents our efforts at identifying new mercury-manganese (HgMn/CP3) stars using spectra obtained with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Suitable candidates were searched for among pre-selected early-type spectra from LAMOST DR4 using a modified version of the MKCLASS code that probes several HgII and MnII features. The spectra of the resulting 332 candidates were visually inspected. Using parallax data and photometry from Gaia DR2, we investigated magnitudes, distances from the Sun, and the evolutionary status of our sample stars. We also searched for variable stars using diverse photometric survey sources. We present 99 bona fide CP3 stars, 19 good CP3 star candidates, and seven candidates. Our sample consists of mostly new discoveries and contains, on average, the faintest CP3 stars known (peak distribution 9.5<=G<=13.5mag). All stars are contained within the narrow spectral temperature-type range from B6 to B9.5, in excellent agreement with the expectations and the derived mass estimates (2.4<=M_{sun}_<=4 for most objects). Our sample stars are between 100Myr and 500Myr old and cover the whole age range from zero-age to terminal-age main sequence. They are almost homogeneously distributed at fractional ages on the main sequence <=80%, with an apparent accumulation of objects between fractional ages of 50% to 80%. We find a significant impact of binarity on the mass and age estimates. Eight photometric variables were discovered, most of which show monoperiodic variability in agreement with rotational modulation. Together with the recently published catalogue of APOGEE CP3 stars, our work significantly increases the sample size of known Galactic CP3 stars, paving the way for future in-depth statistical studies.2021A&A...645A..34Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/645/A34CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)V/153 : LAMOST DR4 catalogs (Luo+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/645/A34https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/645/A34http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/645/A34https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/645/A34https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/645/A34http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/645/A34GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/645/A34/tablea1 (Essential data for our stars, sorted by increasing right ascension)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/645/A34/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/645/A34/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/645/A34/tablea1?GETtext/xml+votable180.050000true0.329166746.73194720.0055555555555555566/1258 1283 1285 1310 1336 1356 1366 1390 1449 1463 1483 1627 1660 1733 1740 1745 1763 1783 1790 1818 1834 1899 1922 1926-1927 1930 1933 1950 1988 2016 2750 2993 3100 3179 3181 3190 3195 3240 4517 5989 6182 6661 6692 6995 7053 8499 12600 13286 13982 14183 14185 14274 14278 14406 14620 14755 14757 15062 15179 22114 22119 22205 22212 22215 22220 22240 22242 22268 22421 22441 22502 22508 23005 23643 23701 23720 23788 23816 23822 23962 23965 23982 23996-23997 24000 24060 24063 24165 24182 24191 24291 24325 24328 24339 24345 24348-24349 24358 24366 24370 24376 24383 24424 24426 24468 24476 24485 24493 24495 24502 24509 24512 24522 24528 24536 24567 25846 261841.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/645/A34?format=asciiOpticaldefaultJ/A+A/645/A34/tablea1Essential data for our stars, sorted by increasing right ascensionSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/125] Sequential numbermeta.recordintLAMOSTLAMOST designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_LAMOST[abcd] Note (1)meta.notecharONameAlternative name (HD number, TYC identifier or Gaia DR2 number)meta.idcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declinaiton (J2000)pos.eq.dec;meta.mainSpTypeFinal spectral type, as derived in this studysrc.spTypecharS/NgSloan g-band sigma-to-noise ratio of the analysed spectrummeta.noteintGmagGaia DR2 G magnitudemagphot.mag;em.optfloate_Gmagrms uncertainty on Gmagmagstat.error;phot.magfloatplx? Gaia DR2 parallaxmaspos.parallax.trigfloatnullablee_plx? rms uncertainty on Plxmasstat.error;pos.parallaxfloatnullable(BP-RP)0? Deredenned Gaia DR2 BP-RP colour indexmagphot.color;em.opt;em.optfloatnullablee_(BP-RP)0? rms uncertainty on (BP-RP)0magstat.errorfloatnullableAGAbsorption in G bandmagphys.absorptionfloatGMAG0? Intrinsic absolute magnitude in Gaia DR2 G bandmagphys.magAbsfloatnullablee_GMAG0? rms uncertainty on GMAG0magstat.errorfloatnullableJ/A+A/645/A34/tablea2Upper limits of variability for the stars identified as non-variable in the accuracy limits of the employed data sourcesULTE? Upper limit of variability as derived from TESS data (semiamplitude)mmagsrc.var.amplitudefloatnullableLAMOSTLAMOST designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/165] Sequential numbermeta.recordintULSW? Upper limit of variability as derived from SWASP data (semiamplitude)mmagsrc.var.amplitudefloatnullableULAS? Upper limit of variability as derived from ASAS-SN data (semiamplitude)mmagsrc.var.amplitudefloatnullableULAS3? Upper limit of variability as derived from ASAS-3 data (semiamplitude)mmagsrc.var.amplitudefloatnullable