J/A+AS/142/347ivo://CDS.VizieR/J/A+AS/142/347CDSDrozdovsky I.Tikhonov N.2001-01-20T20:55:27Z2001-01-20T21:55:22ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-photometryvisible-astronomyWide-band photometryccd-photometryIn this paper we present the results of a detailed B, V, R, I, and H{alpha} study of the isolated nearby blue compact dwarf (BCD) galaxy NGC 6789. The observed galaxy has not yet been resolved into stars up to now. On CCD frames obtained with 6m BTA telescope and 2.5m Nordic telescope the galaxy is well resolved. Its colour-magnitude diagram confirms the two component (core-halo) galaxy morphology, which consists of two stellar populations distinct in structure and colour: an inner high surface-brightness young population within 150pc from the center of the galaxy, and a relatively low surface-brightness intermediate-age population extending out to at least 600pc. The distance to the galaxy, estimated from the tip of the red giant branch (TRGB) is 2.1Mpc which places NGC 6789 close to the Local Group. From the mean colour of the RGB, the mean metal abundance of the halo population is estimated as [Fe/H]=~-1dex.2000A&AS..142..347Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/142/347CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/124/559 : VI photometry of dwarf galaxies (Karanchentsev+ 1997)J/A+AS/128/459 : BV photometry of irregular galaxies (Makarova+ 1998)J/A+AS/131/1 : BVI photometry of 5 CVn cloud galaxies (Karachentsev+ 1998)J/A+AS/133/181 : BVI imaging of 20 irregular galaxies (Makarova+ 1998)J/A+AS/142/425 : BVRI photometry of 6 galaxies (Drozdovsky+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/142/347https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/142/347http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/142/347https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/142/347https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/142/347http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/142/347GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/A+AS/142/347/table2Stellar photometry of NGC 6789recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIdentRunning numbermeta.idintXposX coordinate (1)pixpos.cartesian.x;instr.detintYposY coordinate (1)pixpos.cartesian.y;instr.detintVmagV magnitudemagphot.mag;em.opt.VfloatV-IV-I_c_ colour index (4)magphot.color;em.opt.V;em.opt.IfloatSharpStellar sharpness (2)floatChiALLSTAR stellar image quality diagnostic (see Stetson 1994)stat.errorfloatLocateLocation in reference to the galaxy (3)obs.fieldchar