J/AJ/121/2020ivo://CDS.VizieR/J/AJ/121/2020doi:10.26093/cds/vizier.51212020CDSBianchi L.Scuderi S.Massey P.Romaniello M.2023-04-06T16:50:41Z2001-09-22T14:51:22ZCDS support team

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

cds-question@unistra.frgalaxiesphotometryvisible-astronomybroad-band-photometryWe investigate the massive star population of NGC 6822 with ground-based UBV photometry covering the whole of the galaxy and HST WFPC2 photometry with filters F255W, F336W, F439W, and F555W of two fields containing very rich and crowded OB associations. The four-band WFPC2 photometry is used to derive Teff and E(B-V). H-R diagrams are constructed for the OB associations included in our fields. These show that 10Myr old populations are present in OB 9 and OB 6, while more recent star formation have occurred in OB 8, OB 13, OB 15, and OB 7. Two particularly interesting H II regions, Hubble V and Hubble X, are included in our fields. The luminous massive stars that power these bright H II regions (H{alpha} luminosity several times that of the Orion nebula), could be resolved even in their dense cores thanks to the HST spatial resolution. Our data reveal very young (a few million years), apparently coeval populations, with several massive star candidates.2001AJ....121.2020Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/121/2020CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/110/2715 : UBV photometry in NGC 6822, M31 and M33 (Massey+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/121/2020https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/121/2020http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/121/2020https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/121/2020https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/121/2020http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/121/2020GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/121/2020/table1 (CTIO Photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/121/2020/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/121/2020/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/121/2020/table1?GETtext/xml+votable180.050000true296.22467917-14.908947220.005555555555555556Cone search capability for table J/AJ/121/2020/table3 (WFPC2 Photometry)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/121/2020/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/121/2020/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/121/2020/table3?GETtext/xml+votable180.050000true296.22275-14.749241670.0055555555555555566/29716 29718https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/121/2020?format=asciiOpticaldefaultJ/AJ/121/2020/table1CTIO PhotometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[BSM2001]Star name (CTIO-NNNN, [BSM2001] CTIO-NNNN in Simbad)meta.id;meta.maincharRAJ2000Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainVmagCTIO V-band magnitudemagphot.mag;em.opt.VfloatB-VCTIO (B-V) color indexmagphot.color;em.opt.B;em.opt.VfloatU-BCTIO (U-B) color indexmagphot.color;em.opt.U;em.opt.BfloatJ/AJ/121/2020/table3WFPC2 PhotometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[BSM2001]Star name (LB-f1- NNN or LB-f2- NNN, [BSM2001] LB-f1-NNN or [BSM2001] LB-f2-NNN in Simbad)meta.id;meta.maincharRAJ2000Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainVmagWFPC2 V-band (F555W) magnitudemagphot.mag;em.opt.VfloatBmagWFPC2 B-band (F439W) magnitudemagphot.mag;em.opt.BfloatUmagWFPC2 U-band (F336W) magnitudemagphot.mag;em.opt.UfloatF255WWFPC2 F255W filter magnitudemagphot.mag;em.UV.200-300nmfloat