J/A+A/371/L5ivo://CDS.VizieR/J/A+A/371/L5doi:10.26093/cds/vizier.33719005CDSMaitzen H.M.Paunzen E.Pintado O.I.2001-06-05T22:42:43Z2001-06-05T22:42:14ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsnarrow-band-photometrypeculiar-variable-starsWe report on the detection of the first extragalactic, classical chemically peculiar (CP) stars more than 100 years after the discovery of this group. Using the tool of CCD {Delta}a-photometry, eight definite positive detections in the globular-like stellar cluster NGC 1866 and its surrounding in the Large Magellanic Cloud were made. More than 1950 objects within a radius of 9.5' of the cluster center down to 20.5 magnitude were observed in this three filter, narrow band photometric system. Averaging more than 70 individual frames for all three filters yielded a 3{sigma} detection limit of 0.015mag for stars with V=20mag. Furthermore we found three objects with significantly negative {Delta}a-values indicating either an Ae/shell or {lambda} Bootis nature. The overall percentage of chemically peculiar stars for NGC 1866 (1.5%) seems lower than for the majority of open clusters in our Milky Way whereas the incidence within the LMC field is decisively less (0.3%). For a description of the {Delta}a photometric system, see e.g. <GCPD/75>2001A&A...371...L5Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/371/L5CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/118/2839 : BV photometry of NGC 1866 (Testa+, 1999)J/ApJS/71/25 : NGC 1866 CCD photometry (Brocato+ 1989)J/A+A/373/153 : NGC 2489, 2567, 2658, 5281 and 6208 (Paunzen+, 2001)J/A+A/385/867 : NGC 2439, 3960, 6134, 6192 and 6451 (Paunzen+, 2002)J/A+A/395/823 : Collinder 272, Pismis 20, Lynga 14, NGC 6396 and 6611J/A+A/412/721 : NGC 2099, 3114, 6204, 6705 and 6756 (Paunzen+, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/371/L5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/371/L5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/371/L5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/371/L5https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/371/L5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/371/L5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/371/L5/table1Observed program stars within 1.5' of NGC 1866e_arms uncertainty on amagstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqNotation for stars sorted after X and Ymeta.idintTFC? Notation according to Testa et al. (1999, Cat. <J/AJ/118/2839>)intnullableXposX-coordinate (1pix=0.813")pixpos.cartesian.x;instr.detfloatYposY-coordinate (1pix=0.813")pixpos.cartesian.y;instr.detfloatg1-yMean (g1-y) index (1)magphot.colorfloate_g1-yrms uncertainty on (g1-y)magstat.errorfloataMean a index (a = g2 - [(g1+y)/2]) (1)magphot.colorfloatDeltaaDeviation from cluster line (2)magphot.mag;arith.difffloatymagMean y value (1)magphot.mag;em.opt.Vfloate_ymagrms uncertainty on ymagmagstat.errorfloatNNumber of measurementsmeta.numberintJ/A+A/371/L5/table2Observed program stars in the surrounding of NGC 1866recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqNotation for stars sorted after X and Ymeta.idintTFC? Notation according to Testa et al. (1999, Cat. <J/AJ/118/2839>)intnullableXposX-coordinate (1pix=0.813")pixpos.cartesian.x;instr.detfloatYposY-coordinate (1pix=0.813")pixpos.cartesian.y;instr.detfloatg1-yMean (g1-y) index (1)magphot.colorfloate_g1-yrms uncertainty on (g1-y)magstat.errorfloataMean a index (a = g2 - [(g1+y)/2]) (1)magphot.colorfloate_arms uncertainty on amagstat.errorfloatDeltaaDeviation from cluster line (2)magphot.mag;arith.difffloatymagMean y value (1)magphot.mag;em.opt.Vfloate_ymagrms uncertainty on ymagmagstat.errorfloatNNumber of measurementsmeta.numberint