J/MNRAS/460/1970ivo://CDS.VizieR/J/MNRAS/460/1970doi:10.26093/cds/vizier.74601970CDSBowman D.M.Kurtz D.W.Breger M.Murphy S.J.Holdsworth D.L.2024-08-16T20:17:14Z2016-06-16T12:47:00ZCDS support team

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

cds-question@unistra.frvariable-starsa-starsWe present the results of a thorough search for amplitude modulation of pulsation modes in 983 {delta} Sct stars, which have effective temperatures between 6400<T_eff_<10000K in the Kepler Input Catalogue and were continuously observed by the Kepler Space Telescope for 4yr. We demonstrate the diversity in pulsational behaviour observed, in particular non-linearity, which is predicted for {delta} Sct stars. We analyse and discuss examples of {delta} Sct stars with constant amplitudes and phases; those that exhibit amplitude modulation caused by beating of close-frequency pulsation modes; those that exhibit pure amplitude modulation (with no associated phase variation); those that exhibit phase modulation caused by binarity; and those that exhibit amplitude modulation caused by non-linearity. Using models and examples of individual stars, we demonstrate that observations of the changes in amplitude and phase of pulsation modes can be used to distinguish among the different scenarios. We find that 603 {delta} Sct stars (61.3 per cent) exhibit at least one pulsation mode that varies significantly in amplitude over 4yr. Conversely, many {delta} Sct stars have constant pulsation amplitudes so short-length observations can be used to determine precise frequencies, amplitudes and phases for the most coherent and periodic {delta} Sct stars. It is shown that amplitude modulation is not restricted to a small region on the HR diagram, therefore not necessarily dependent on stellar parameters such as T_eff_, logg or [Fe/H]. Our catalogue of 983 {delta} Sct stars will be useful for comparisons to similar stars observed by K2 and TESS, because the length of the 4-yr Kepler data set will not be surpassed for some time.2016MNRAS.460.1970Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/460/1970CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/211/2 : Q1-16 Kepler targets revised stellar properties (Huber+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/460/1970https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/460/1970http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/460/1970https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/460/1970https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/460/1970http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/460/1970GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/460/1970/table1 (Stellar parameters for the {delta} Sct stars discussed in this paper, as listed in Huber et al. (2014, Cat. J/ApJS/211/2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/460/1970/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/460/1970/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/460/1970/table1?GETtext/xml+votable180.050000true291.1063836.79230890.0055555555555555564/933 5/3646-3647 3683 3689-3694 3741-3743 3776 3778 3780 3782 3784 3792 6/14567 14573 14575 14577-14579 14582 14738 14744 14746-14747 14749-14751 14782 14792 14794-14795 14816-14817 14827 14830 14915 14917-14921 14923-14925 14949 14954 14958-14961 14963 15040-15041 15043 15057 15060-15062 15109-15111 15117-15119 15124-15126 15133-15135 15140-15141 15144 15152-15153 15155-15158 15172-15174 15200https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/460/1970?format=asciidefaultJ/MNRAS/460/1970/table1Stellar parameters for the {delta} Sct stars discussed in this paper, as listed in Huber et al. (2014, Cat. J/ApJS/211/2)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintH14Display the data of Huber et al., 2014, Cat. J/ApJS/211/2meta.ref.urlcharKICKIC identification numbermeta.id;meta.mainintTeff? effective temperature (1)Kphys.temperature.effectiveintnullablelogg? surface gravity (1)log(cm.s**-2)phys.gravityfloatnullable[Fe/H]? metallicity (1)phys.abund.ZfloatnullablekepmagKepler magnitudemagphot.mag;em.optfloatNoModNumber of constant-amplitude pulsation mode frequencies above our amplitude cut-off of 0.10mmagmeta.numberintAModNumber of variable-amplitude pulsation mode frequencies above our amplitude cut-off of 0.10mmagmeta.numberint_RAPositions from the Kepler Input Catalog (V/133) (right ascension part)degpos.eq.ra;meta.main_DEPositions from the Kepler Input Catalog (V/133) (declination part)degpos.eq.dec;meta.main