J/AJ/154/31ivo://CDS.VizieR/J/AJ/154/31doi:10.26093/cds/vizier.51540031CDSGray R.O.Riggs Q.S.Koen C.Murphy S.J.Newsome I.M.Corbally C.J.,Cheng K.-P.Neff J.E.2017-11-06T14:38:33Z2017-10-11T14:29:09ZCDS support team

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

cds-question@unistra.frpeculiar-variable-starsearly-type-starsstellar-spectral-typeseffective-temperaturechemical-abundancesinterstellar-reddeningThe {lambda} Boo stars are a class of chemically peculiar Population I A-type stars characterized by under-abundances of the refractory elements, but near-solar abundances of carbon, nitrogen, oxygen, and sulfur. There is some evidence that {lambda} Boo stars have higher frequencies of "bright" debris disks than normal A-type stars. The discovery of four exoplanets orbiting HR8799, a {lambda} Boo star with a resolved debris disk, suggests that the {lambda} Boo phenomenon may be related to the presence of a dynamic debris disk, perhaps perturbed by migrating planets. However, only 64 {lambda} Boo stars are known, and those stars were discovered with different techniques, making it problematic to use that sample for statistical purposes, including determining the frequency of debris disks. The purpose of this paper is to derive a new sample of {lambda} Boo stars using a technique that does not lead to biases with respect to the presence of infrared excesses. Through spectroscopic observations in the southern hemisphere, we have discovered 33 {lambda} Boo stars and have confirmed 12 others. As a step toward determining the proportion of {lambda} Boo stars with infrared excesses, we have used WISE data to examine the infrared properties of this sample out to 22{mu}m. On this basis, we cannot conclude that {lambda} Boo stars have a greater tendency than normal A-type stars to show infrared excesses. However, observing this sample at longer wavelengths may change that conclusion, as many {lambda} Boo debris disks are cool and do not radiate strongly at 22{mu}m.2017AJ....154...31Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/154/31CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/259 : The Tycho-2 Catalogue (Hog+ 2000)J/other/PASA/32.36 : {lambda} Boo star membership evaluations (Murphy+, 2015)J/MNRAS/410/190 : Young runaway stars within 3kpc (Tetzlaff+, 2011)J/ApJS/188/473 : Chandra variable guide star catalog (Nichols+, 2010)J/AJ/140/184 : RAVE double-lined spec. binaries (Matijevic+, 2010)J/ApJS/168/277 : HK-Survey field HB candidates (Beers+, 2007)J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)J/A+A/373/625 : uvbyB photometry of lambda Bootis stars (Paunzen+, 2001)J/ApJ/469/355 : T_eff_, B-V and BC relation (Flower, 1996)J/ApJS/96/461 : Far-UV Point Sources from FAUST (Bowyer+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/154/31https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/154/31http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/154/31https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/154/31https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/154/31http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/154/31GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/154/31/table4 (Miscellaneous infrared excesses)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/31/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/31/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/31/table4?GETtext/xml+votable180.050000true33.1961917-44.48901560.005555555555555556Cone search capability for table J/AJ/154/31/table1 (TYCHO sample: spectral types, models, E(B-V), and infrared excesses)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/31/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/31/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/31/table1?GETtext/xml+votable180.050000true51.7771875-3.26985440.005555555555555556Cone search capability for table J/AJ/154/31/table2 (Miscellaneous sample: spectral types, models, E(B-V), and infrared excesses)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/154/31/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/154/31/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/154/31/table2?GETtext/xml+votable180.050000true7.8861169-62.95821860.0055555555555555566/16543 16703 16940 17199 17264 17312 17339 17383 17716 17765 17817 18826 18993 19040 19072 20575 20746 20889 20894 20904 20962 20993 21174 21207 21313 21348 21378 21575 21623 21629 21631 21725 21770 21784 21794 21795 21898 22543 22546 22558 22559 22681 22689 22701 22738 22813 22817 22829 22837 22919 23041 23141 23172 24813 24839 24850 24876 24882 25100 25497 25924 26176 26191 26698 26736 26775 26886 26917 27024 27170 27235 27271 27272 27282 27300 28762 28994 29245 29247 29382 29428 29568 29641 29754 29763 29789 29816 29841 29855 29888 29976 29980 29985 30001 30027 30229 30261 30540 30853 30878 31232 31259 31284 31360 32863 33043 33117 33421 34043 34679 34680 34823 35104 35132 35531 35752 35946 35986 35996 36186 36343 36676 36890 36892 36901 37052 37061 37149 37186 37193 37402 37469 37516 37576 37758 37916 38109 38132 38164 38225 38238 38283 38349 38545 38551 38577 38600 38792 38796 38980 39061 39106 39228 39424 39596 39610 39986 40029 40033 40042 40164 40176 40187 40205 40331 40364 40446 40477 40515 40529 40691 40703 40735 40821 40869 40876 40877 40888 40900 40904 40911 40917 40941 41110 41148 41287 41333 41427 41555 41561 41795 42048 42055 42076 42077 42249 42328 42375 42421 42618 42644 42680 42688 42706 42709 42839 42904 43009 43019 43196 43245 43275 43276 43458 43481 43508 43572 43629 43663 43684 43722 43732 44154 44187 44213 44241 44245 44251 44290 44362 44439 44446 44466 44479 44592 44759 44806 44906 44931 44935 44973 44980 45006 45071 45079 45115 45209 45643 45745 45835 45928 45948 46211 46234 46979 47110 47147 47164 47236 47266 47267 47281 47305 47357 47409 47520 47613 47619 47623 47639 47760 47827 47867 47911 47941 47981 48299 48392 48874 48894 48989 49016 49066https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/154/31?format=asciiOpticaldefaultJ/AJ/154/31/table3TYCHO infrared excessesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTYC1[4868/9431] TYC1 of Tycho identifiermeta.id.part;meta.mainintTYC2[232/3603] TYC2 of Tycho identifiermeta.id.part;meta.mainintTYC3[1/1] TYC3 of Tycho identifiermeta.id.part;meta.mainintTeffEffective temperature (table1)meta.ref.urlcharSpTSpectral typesrc.spTypeJHKIf an excess is detected in one or more 2MASS bands, that band is noted (G3)meta.codecharW1[0.08/0.2]? Infrared excess (E) in WISE W1 band (G4)phot.flux;arith.ratiofloatnullableNs1[3.9/6.8]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableW2[0.11/0.2]? Infrared excess (E) in WISE W2 band (G4)phot.flux;arith.ratiofloatnullableNs2[5.4/8.4]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableW3[0.1/1.16]? Infrared excess (E) in WISE W3 band (G4)phot.flux;arith.ratiofloatnullableNs3[2.7/12]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableW4[0.2/2.4]? Infrared excess (E) in WISE W4 band (G4)phot.flux;arith.ratiofloatnullablel_W4[<] Upper limit flag on W4meta.code.errorcharNs4[2/6.1]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableN[N] Indicates a note on an individual source in Section 6.1.1 (see note1.dat file)meta.notecharNoteOther notes (d, d?, EB, and/or SB) (G2)meta.notecharJ/AJ/154/31/note2Miscellaneous sample: notes on individual starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharNoteNotesmeta.noteJ/AJ/154/31/table4Miscellaneous infrared excessesn_JHKNote on JHKmeta.notecharW1[0.1/12]? Infrared excess (E) in WISE W1 band (G4)phot.flux;arith.ratiofloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (mostly Henry Draper identifier)meta.id;meta.maincharTeffEffective temperature (table2)meta.ref.urlcharSpTSpectral typesrc.spTypeJHKIf an excess is detected in one or more 2MASS bands, that band is noted (G3)meta.codecharNs1[4/27]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableW2[0.1/29]? Infrared excess (E) in WISE W2 band (G4)phot.flux;arith.ratiofloatnullableNs2[2.3/40]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableW3[0.1/208]? Infrared excess (E) in WISE W3 band (G4)phot.flux;arith.ratiofloatnullableNs3[4.4/155]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableW4[0.1/2199]? Infrared excess (E) in WISE W4 band (G4)phot.flux;arith.ratiofloatnullablel_W4[<] Upper limit flag on W4meta.code.errorcharNs4[2.3/181]? Number of standard deviations by which the observed flux exceeds the theoretical flux ({sigma}; see Section 5 in the text)meta.numberfloatnullableN[N] Indicates a note on an individual source in Section 6.2.1 (see note2.dat file)meta.notecharNoteOther notes (Algol, d, EB, EB?, d?, or/and VB) (G2)meta.notecharSimbadNameSimbad column added by the CDSmeta.idchar_RAPosition from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/AJ/154/31/table1TYCHO sample: spectral types, models, E(B-V), and infrared excessesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTYC1[4712/9528] TYC1 of Tycho identifiermeta.id.part;meta.mainintTYC2[23/5115] TYC2 of Tycho identifiermeta.id.part;meta.mainintTYC3[1] TYC3 of Tycho identifiermeta.id.part;meta.mainintONameOther identifiermeta.idcharExcIndicates infrared Excess (table3)meta.numberintnullableSpTSpectral type(s) (G1)src.spTypeTeff[6950/10800] Model effective temperatureKphys.temperature.effective;meta.modelledintlogg[3.3/4.2] Model log surface gravitylog(cm.s**-2)phys.gravity;meta.modelledfloat[M/H][-1.5/0.5] Model metallicity, relative to Sunlog(Sun)phys.abund.Z;meta.modelledfloatE(B-V)[0/0.231] Optical color excessmagphot.color.excessfloatIRInfrared excess notes (I, Comp, Comp?, EB, n, or W4<) (1)meta.notecharN[N] Indicates a note on an individual source in Section 6.1.1 (see note1.dat file)meta.notecharSBIndicates a Spectroscopic Binarymeta.codechar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar_RAPosition from SIMBAD database (right ascension part)degpos.eq.ra;meta.mainnullable_DEPosition from SIMBAD database (declination part)degpos.eq.dec;meta.mainnullableJ/AJ/154/31/table2Miscellaneous sample: spectral types, models, E(B-V), and infrared excessesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName (mostly Henry Draper identifier)meta.id;meta.maincharONameOther identifiermeta.idcharExcIndicates infrared Excess (table4)meta.numberintnullableSpTSpectral type(s) (G1)src.spTypeTeff[6750/11500] Model effective temperatureKphys.temperature.effective;meta.modelledintlogg[3.3/4.2] Model log surface gravitylog(cm.s**-2)phys.gravity;meta.modelledfloat[M/H][-1.5/0.2] Model metallicity, relative to Sunlog(Sun)phys.abund.Z;meta.modelledfloatE(B-V)[0/0.462] Optical color excessmagphot.color.excessfloatIRInfrared excess notes (I, I?, Comp, n, or W4<) (1)meta.notecharN[N] Indicates a note on an individual source in Section 6.2.1 (see note2.dat file)meta.notecharMm? {lambda} Boo membership evaluation (1, 2, 3, or 4) (2)meta.code.memberintnullableNoteOther notes (EB, SB, VB, and/or u) (G2)meta.notecharM15Indicates a star from Murphy et al. 2015 (Cat. J/other/PASA/32.36)meta.ref.urlintnullable_RAPosition from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/AJ/154/31/note1TYCHO sample: notes on individual starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTYC1TYC1 of Tycho identifiermeta.id.part;meta.mainintTYC2TYC2 of Tycho identifiermeta.id.part;meta.mainintTYC3TYC3 of Tycho identifiermeta.id.part;meta.mainintNoteNotesmeta.note