J/A+A/410/905ivo://CDS.VizieR/J/A+A/410/905doi:10.26093/cds/vizier.34100905CDSPatriarchi P.Morbidelli L.Perinotto M.2018-01-04T08:21:42Z2003-12-29T13:45:13ZCDS support team

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

cds-question@unistra.fro-starsinfrared-photometryinterstellar-mediuminterstellar-reddeningWe present new measurements of the interstellar reddening parameter R_V_=A_V_/E(B-V) towards 185 O stars, using J, H, Ks photometry from the 2MASS project. The average R_V_ from these is of 3.19+/-0.50. All objects whose R_V_ departs from this value by more than 2 sigma have been recognized. Ten objects have R_V_ higher than this value and two lower. In the Cygnus region R_V_ values follow the behaviour of the general interstellar medium, while in the Carina arm, in spite of the relatively larger distance, local cloud effects prevail. The relatively few stars of our sample whose Hipparcos parallaxes are reliable, are found to have distances systematically smaller than the distances derived by the spectroscopic parallaxes. We argue that this effect is consistent with the recently claimed discovery of grey extinction towards OB stars.2003A&A...410..905Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/410/905CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/410/905https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/410/905http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/410/905https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/410/905https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/410/905http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/410/905GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/410/905/table1 (J, H, Ks photometry of O stars from 2MASS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/410/905/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/410/905/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/410/905/table1?GETtext/xml+votable180.050000true4.42942451.433090.0055555555555555565/3661 6/1287 1297 1299 1302-1303 1332 1355 1814 2806 3214 3231 12943 13999 14179 14353 14355 14456 14605 14619 14622-14624 14630-14633 14636 14641 14643 14653-14655 14658 14683 14689-14690 14692-14693 14716 14740-14741 14743 14745 14793 15394 15683 20849 21504 21510 21518 21531 21635 21638 21647 22033 22038 22088 23774 23780 23851 23962 23969 23982 23984 23995 23998 24179 24325 24328 24426 24466 24496 24554-24555 28687 28719 28796 28803 28819 28830 28833 28848 28895 28900 28907 28913 28915 29025 29036 29089 29091 29098 29158 29166-29167 29185 29190 29300 37333 38016 39374 39386 39410 39700 39711 39733 39771 39774-39775 39788 39793 39799 39803-39804 39873 39876 39931 40618 42456 42458 42471 42483https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/410/905?format=asciiInfrareddefaultJ/A+A/410/905/table1J, H, Ks photometry of O stars from 2MASSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar identificationmeta.id;meta.maincharprimaryVmagVisual magnitudemagphot.mag;em.opt.VfloatJmagJ magnitude (1)magphot.mag;em.IR.Jfloate_JmagError of J magnitudemagstat.errorfloatHmagH magnitude (1)magphot.mag;em.IR.Hfloate_HmagError of H magnitudemagstat.errorfloatKsmagKs magnitude (1)magphot.mag;em.IR.Kfloate_KsmagError of Ks magnitudemagstat.errorfloatSimbadSimbad column added by the CDSmeta.refchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/410/905/table2Extinction parameters and distance from spectroscopic parallaxrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar identificationmeta.id;meta.maincharn_Name[*] Individual note (1)meta.notecharSpTypeMK Spectral typesrc.spTypecharE(B-V)E(B-V) colour excessmagphot.color.excessfloatAvExtinction at Vmagphys.absorptionfloate_AvError of Avmagstat.errorfloatRvTotal-to-selective extinction ratio, Rv=Av/E(B-V)phys.absorptionfloate_RvError of Rvstat.errorfloatAssocStellar association namemeta.id.parentcharDistDistance derived from spectroscopic parallaxkpcpos.distancefloatu_Rv[sl] See Note (2)meta.code.errorchar