J/AJ/150/204ivo://CDS.VizieR/J/AJ/150/204doi:10.26093/cds/vizier.51500204CDSJoner M.D.Hintz E.G.2017-07-10T15:25:33Z2016-06-13T12:51:38ZCDS support team

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

cds-question@unistra.fropen-star-clustersstellar-spectral-typesWe define an H{alpha} photometric system that is designed as a companion to the well established H{beta} index. The new system is built on spectrophotometric observations of field stars as well as stars in benchmark open clusters. We present data for 75 field stars, 12 stars from the Coma star cluster, 24 stars from the Hyades, 17 stars from the Pleiades, and 8 stars from NGC 752 to be used as primary standard stars in the new systems. We show that the system transformations are relatively insensitive to the shape of the filter functions. We make comparisons of the H{alpha} index to the H{beta} index and illustrate the relationship between the two systems. In addition, we present relations that relate both hydrogen indices to equivalent width and effective temperature. We derive equations to calibrate both systems for Main Sequence stars with spectral types in the range O9 to K2 for equivalent width and A2 to K2 for effective temperature.2015AJ....150..204Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/150/204CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/176/262 : VRI photometry in open clusters (Taylor+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/150/204https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/150/204http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/150/204https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/150/204https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/150/204http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/150/204GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/150/204/stars (H{alpha} and H{beta} for field stars (table 2) , and for stars in open clusters (tables 3--5))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/150/204/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/150/204/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/150/204/stars?GETtext/xml+votable180.050000true4.272911938.68163610.005555555555555556Cone search capability for table J/AJ/150/204/table6 (H{alpha} and H{beta} for stars in NGC 752)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/150/204/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/150/204/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/150/204/table6?GETtext/xml+votable180.050000true26.414753937.86281080.0055555555555555566/137 309 322 333 340 349 373 461 462 463 472 473 474 485 496 498 684 765 903 1032 1033 1035 1058 1060 1458 2340 2436 2440 2472 2591 2664 2690 2697 3258 5009 5230 5304 5731 6181 6339 6777 8476 9125 9403 9759 10101 10375 11120 11204 12621 12865 13557 13682 13688 14126 14459 14478 14522 14797 15170 15174 15261 15621 15747 16069 17395 18942 19507 19585 20278 22275 23344 23454 23501 23502 23503 23518 23526 23529 23532 23545 23547 23611 24223 25973 26457 26521 26575 26975 27088 28092 28093 28094 28131 28142 28233 28469 28484 28485 28486 28489 28490 28605 29893 30114 30576 30580 30655 31776 32061 32142 32192 32288 32558 32757 40932 44542https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/150/204?format=asciiOpticaldefaultJ/AJ/150/204/starsH{alpha} and H{beta} for field stars (table 2) , and for stars in open clusters (tables 3--5)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterField or clustermeta.id.parentcharf_HDFlag "A" indicates an additional starmeta.codecharHD[1280/285252]? HD number of the starmeta.idintnullableNameStar name (1)meta.id;meta.maincharSpTSpectral typesrc.spTypecharHalpha[2.6/2.91] The H{alpha} indexspect.index;em.line.Halphadoublee_Halpha[0/0.012] Error in H{alpha} ({sigma}_o_)stat.errordoubleHbeta[2.5/2.91] The H{beta} indexspect.index;em.line.Hbetadoublee_Hbeta[0.00029/0.027] Error in H{beta} ({sigma}_o_)stat.errordoubleNo[2/191] Total number of observationsmeta.numberintNn[1/64] Number of nights observedmeta.numberint_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/AJ/150/204/table6H{alpha} and H{beta} for stars in NGC 752SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBD? BD numbermeta.idcharName[126/220] Star identification number from Heinemann (1926AN....227..193H)meta.id;meta.mainintSpTSpectral typesrc.spTypecharHalpha[2.6/2.9] The H{alpha} indexspect.index;em.line.Halphadoublee_Halpha[0.002/0.01] Error in H{alpha}stat.errordoubleHbeta[2.57/2.91] The H{beta} indexspect.index;em.line.Hbetadoublee_Hbeta[0.0015/0.015] Error in H{beta}stat.errordoubleNo[4/11] Total number of observationsmeta.numberintNn[2/6] Number of nights observedmeta.numberint_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.main