J/AJ/162/32ivo://CDS.VizieR/J/AJ/162/32doi:10.26093/cds/vizier.51620032CDSQin L.Luo A.-L.Hou W.Li Y.-B.Cui K.-M.Zuo F.Zhang S.Wang R.,Han J.-S.Wang L.-L.Lu Y.Chen X.-L.2022-03-21T12:10:05Z2021-11-29T08:34:58ZCDS support team

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

cds-question@unistra.fram-starsstellar-agesstellar-massesstellar-radiieffective-temperaturevisible-astronomyRotation is a critical physical process operating in the formation of Am stars. There is a strong correlation between low-velocity rotation and chemical peculiarity. However, the existence of many non-chemical-peculiar slow rotators challenges the understanding of Am stars. The purpose of our work is to search for low-velocity rotating non-chemical-peculiar A-type stars and Am stars and to make a comparative analysis. In this paper, we pick out a sample from the LAMOST-Kepler project, including 21 Am stars, 125 non-chemical-peculiar slow rotators, and 53 non-chemical-peculiar fast rotators. We calculate the rotational frequencies through a periodic change of light curves caused by inhomogeneous stellar surfaces and then obtain the rotational velocities. For slow rotators, the age of Am stars is statistically younger than that of non-chemical-peculiar stars in the same temperature bin. In the comparison of the period, the average amplitude, and stellar mass of Am and non-chemical-peculiar stars, we discover that there is no difference in the photometric variability between Am and non-chemical-peculiar stars, which implies similar inhomogeneities on the surfaces. The average amplitude of non-chemical-peculiar stars has a downward trend with the increase of effective temperature and stellar mass, which is consistent with the theoretical prediction caused by weak dynamo-generated magnetic fields in A-type stars. In addition, we confirm four non-chemical-peculiar stars that have flares by checking field-of-view images, pixel images, and pixel-level light curves.2021AJ....162...32Qhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/162/32CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)V/164 : LAMOST DR5 catalogs (Luo+, 2019)J/ApJS/99/135 : A-type stars rotation and spectral peculiarities (Abt+ 1995)J/A+A/537/A120 : Rotational velocities of A-type stars. IV. (Zorec+, 2012)J/MNRAS/431/2240 : Activity in A-type stars from Kepler (Balona, 2013)J/MNRAS/432/1203 : Rotation periods of M-dwarf stars (McQuillan+, 2013)J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)J/AJ/150/133 : Stellar noise 4529 Kepler solar-type dwarfs (Gilliland+, 2015)J/ApJS/220/19 : LAMOST obs. in the Kepler field. I. (De Cat+, 2015)J/AJ/151/13 : LAMOST-Kepler MKCLASS spectral classification (Gray+, 2016)J/AJ/151/68 : Kepler Mission. VII. Eclipsing binaries in DR3 (Kirk+, 2016)J/MNRAS/467/1830 : Starspots on A stars (Balona, 2017)J/ApJS/241/29 : Flare catalog through LC data of Kepler DR25 (Yang+, 2019)J/A+A/640/A40 : 1002 mCP stars from LAMOST DR4 (Hummerich+, 2020)J/AJ/159/280 : Gaia-Kepler stellar prop. catalog.I. KIC stars (Berger+, 2020)J/ApJS/249/22 : Radial velocity variable stars from LAMOST DR4 (Tian+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/162/32https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/162/32http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/162/32https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/162/32https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/162/32http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/162/32GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/162/32/table1 (The non-CP stars and Am stars included in this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/162/32/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/162/32/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/162/32/table1?GETtext/xml+votable180.050000true294.432843.8170390.0055555555555555565/3683 3688 3692 3704 3780 6/14567 14578-14579 14581-14584 14586-14589 14731 14744 14746 14750-14751 14756-14757 14761-14763 14767 14772-14773 14775 14777-14779 14781 14792 14794 14825-14828 14830 14917-14918 14929 14931-14933 14935 14941 14947 14955 14959-14960 14962-14963 14965-14966 14971-14973 15040 15045 15061 15104 15107 15112 15114-15115 15119 15124 15126-15129 15131-15132 15134-15136 15140 15143 15145 15147-15148 15154 15157 15160 15168-15169 15171-15172https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/162/32?format=asciiOpticaldefaultJ/AJ/162/32/table1The non-CP stars and Am stars included in this studySimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFileFile identifiermeta.id;meta.filecharLAMOSTLAMOST identifiermeta.id;meta.mainlongKICKepler Input Catalog identifiermeta.id.crossintRAJ2000[280/302] Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000[36/52] Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainFrot[0.05/2.93] Rotational frequencyd**-1pos.ephemdoublee_Frot[6E-7/3E-4] Uncertainty in fd**-1stat.errordoubleVC[0.05/0.66]? Coefficient of variationstat.fit.paramdoublenullableAmp[72.9/35127] Average light curve amplitude (1)umagsrc.var.amplitudedoublee_Amp[17/17233] Standard deviation in Ampumagstat.errordoubleVRot[5.66/317.8] Rotation velocitykm/sphys.veloc.rotatdoubleE_VRot[0.1/33] Upper uncertainty in VRotkm/sstat.error;stat.maxfloate_VRot[0.1/27] Lower uncertainty in VRotkm/sstat.errorfloatTeff[6067/10963] Effective temperature (2)Kphys.temperature.effectivefloatE_Teff[114/1432] Upper uncertainty in TeffKstat.error;stat.maxfloate_Teff[112/2261] Lower uncertainty in TeffKstat.error;phys.temperature.effectivefloatlogg[3.54/4.43] log surface gravity (2)log(cm.s**-2)phys.gravityfloatE_logg[0.01/0.3] Upper uncertainty in log(g)log(cm.s**-2)stat.error;stat.maxfloate_logg[0.02/0.3] Lower uncertainty in log(g)log(cm.s**-2)stat.errorfloat[Fe/H][-0.6/0.37] Metallicity (2)log(Sun)phys.abund.ZfloatE_[Fe/H][0.06/0.2] Upper uncertainty in [Fe/H]log(Sun)stat.error;stat.maxfloate_[Fe/H][0.09/0.3] Lower uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.FefloatMass[1.04/2.75] Mass (2)solMassphys.massfloatE_Mass[0.03/0.4] Upper uncertainty in MasssolMassstat.error;stat.maxfloate_Mass[0.03/0.6] Lower uncertainty in MasssolMassstat.error;phys.massfloatRad[1.03/4.51] Radius (2)solRadphys.size.radiusfloatE_Rad[0.02/0.97] Upper uncertainty in RadiussolRadstat.error;stat.maxfloate_Rad[0.02/0.55] Lower uncertainty in RadiussolRadstat.errorfloatAge[0.14/3.75] Age (2)Gyrtime.agefloatE_Age[0.05/1.5] Upper uncertainty in AgeGyrstat.error;stat.maxfloate_Age[0.03/1.2] Lower uncertainty in AgeGyrstat.error;time.agefloatNoteAdditional note (3)meta.noteintBerger+Display data from Berger+, 2020, J/AJ/159/280meta.ref.urlchar