J/AJ/121/318ivo://CDS.VizieR/J/AJ/121/318doi:10.26093/cds/vizier.51210318CDSAlves D.R.Bond H.E.Onken C.2023-04-06T16:50:43Z2005-09-03T14:54:07ZCDS support team

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

cds-question@unistra.frglobular-star-clustersccd-photometryvisible-astronomyWide-band photometryWe have obtained new CCD BV photometry of the little-studied southern Galactic globular cluster NGC 5986, including light curves of five of its RR Lyrae variables. The cluster's red giant branch bump is detected for the first time, at V=16.47 +/-0.03. We derive a reddening and true distance modulus of E(B-V)=0.29+/-0.02 and (m-M)_0_=15.15+/-0.10, respectively. The cluster's color-magnitude diagram reveals a mostly blue horizontal branch, like that of M13 or M2, and quite unlike M3; yet all of these clusters have nearly identical metallicities ([Fe/H]_CG97_=-1.35). We show that the RR Lyrae variables in NGC 5986 are about 0.2mag brighter on average than those in M3, an important exception to the often-employed, universal M_V_(RR)-[Fe/H] relation. Finally, we note that NGC 5986 contains two luminous stars with spectral types A-F, which are likely to be post-asymptotic giant branch (PAGB) objects. The V-band luminosity function of such yellow PAGB stars is a promising standard candle. We suggest that the luminosity function is sharply peaked at M_V_(PAGB)=-3.28+/-0.07.2001AJ....121..318Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/121/318CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/97 : Updated 3rd Cat Variable Stars in Globular Clusters (Clement+ 1997)J/A+AS/144/5 : Nearby globular clusters photometric catalog (Rosenberg+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/121/318https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/121/318http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/121/318https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/121/318https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/121/318http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/121/318GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/121/318/table1 (Calibrated BV photometry of NGC 5986 and surrounding field)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/121/318/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/121/318/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/121/318/table1?GETtext/xml+votable180.050000true236.53383-37.7803840.0055555555555555566/42700https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/121/318?format=asciiOpticaldefaultJ/AJ/121/318/table1Calibrated BV photometry of NGC 5986 and surrounding fieldrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStellar ID numberintXpixX pixel position (1)pixdoubleYpixY pixel position (1)pixdoubleBmagB-band magnitudemagfloate_BmagUncertainty in BmagmagfloatVmagV-band magnitudemagfloate_VmagUncertainty in VmagmagfloatCommComment on ID (2)char_RAPosition (computed from Xpix and Ypix) (right ascension part)degpos.eq.ra;meta.main_DEPosition (computed from Xpix and Ypix) (declination part)degpos.eq.dec;meta.mainJ/AJ/121/318/table2Time Series BV Photometry of Variable StarsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameVariable star identification (VNN)charVmagV-band magnitudemagfloate_VmagUncertainty in VmagmagfloatJD-VmagJulian date of Vmag observationddoubleBmagB-band magnitudemagfloate_BmagUncertainty in BmagmagfloatJD-BmagJulian date of Bmag observationddouble