J/AJ/154/72ivo://CDS.VizieR/J/AJ/154/72doi:10.26093/cds/vizier.51540072CDSDavidge T.J.2017-12-13T19:49:47Z2017-11-09T12:52:30ZCDS support team

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

cds-question@unistra.fropen-star-clustersvisible-astronomysloan-photometryImages and spectra recorded with the Gemini Multi-Object Spectrograph on Gemini South are used to investigate the stellar content of the open cluster Haffner 16. The (i',g'-i') color-magnitude diagram (CMD) constructed from these data extends over 10mag in i', sampling the cluster main sequence (MS) and 5mag of the pre-MS (PMS). The fraction of unresolved equal mass binaries among PMS stars is estimated to be 0.6+/-0.1. The isochrones do not track the PMS on the CMD, in the sense that the PMS has a shallower slope on the CMD than predicted by the models. Still, a dip in star counts, which is associated with the relaxation of PMS stars onto the MS, is identified near i'=17. The depth and brightness of this feature-as well as the morphology of the cluster MS on the CMD-are matched by models with a slightly sub-solar metallicity that have an age of ~20Myr and a distance modulus of 12.3+/-0.2. A light profile of Haffner 16 is constructed in the W1 filter ({lambda}_cen_=3.4{mu}m), which suggests that the cluster is surrounded by a diffuse stellar halo. Spectra of candidate cluster MS and PMS stars selected according to location on the CMD are presented. The spectra show characteristics that are suggestive of a sub-solar metallicity. H{alpha} emission is common among objects on the PMS locus on the CMD near i'=18. It is suggested that the location of the Haffner 16 PMS on the CMD is affected by large-scale cool spot activity, likely induced by rapid stellar rotation.2017AJ....154...72Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/154/72CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/232 : STELIB: A library of stellar spectra at R~2000 (Le Borgne+, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/154/72https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/154/72http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/154/72https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/154/72https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/154/72http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/154/72GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/154/72/table4 (Spectroscopic targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/72/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/72/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/72/table4?GETtext/xml+votable180.050000true117.54356889-25.473770.0055555555555555566/39806 39807https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/154/72?format=asciiOpticaldefaultJ/AJ/154/72/table4Spectroscopic targetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar identification number (1)meta.id;meta.maincharf_Star[ab*] Flag on Star (*=star that have multiple observations; a and b=stars that are in the same slitlet)meta.codecharOStarStar identification number in other mask(s) (1)meta.idcharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainXpix[938.8/2619.7] X pixel coordinate (2)pixpos.cartesian.xfloatYpix[195.7/2211] Y pixel coordinate (2)pixpos.cartesian.yfloati'mag[13.65/19.78]? The i' band magnitudemagphot.mag;em.opt.Ifloatnullableg'-i'[-0.26/2.61]? The (g'-i') color indexmagphot.colorfloatnullable