J/ApJ/775/45ivo://CDS.VizieR/J/ApJ/775/45doi:10.26093/cds/vizier.17750045CDSvan Belle G.T.Paladini C.Aringer B.Hron J.Ciardi D.2017-09-20T05:13:57Z2015-04-08T12:54:36ZCDS support team

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

cds-question@unistra.frcarbon-starsinfrared-sourcesinterferometrystellar-radiiphotometrysurveysWe report new interferometric angular diameter observations of 41 carbon stars observed with the Palomar Testbed Interferometer. Two of these stars are CH carbon stars and represent the first such measurements of this subtype. Of these, 39 have Yamashita spectral classes and are of sufficiently high quality that we can determine the dependence of effective temperature on spectral type. We find that there is a tendency for the effective temperature to increase with increasing temperature index by ~120K per step, starting at T_eff_=~2500K for C3, y, although there is a large amount of scatter in this relationship. Overall, the median effective temperature of the carbon star sample is 2800+/-270 K and the median linear radius is 360+/-100R_{sun}_. We also find agreement, on average within 15K, with the T_eff_ determinations of Bergeat et al. (J/A+A/369/178) and a refinement of the carbon star angular size prediction based on V & K magnitudes is presented that is good to an rms of 12%. A subsample of our stars have sufficient {u, v} coverage to permit non-spherical modeling of their photospheres, and a general tendency for detection of statistically significant departures from sphericity with increasing interferometric signal-to-noise is seen. The implications of most -and potentially all- carbon stars being non-spherical is considered in the context of surface inhomogeneities and a rotation-mass-loss connection.2013ApJ...775...45Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/775/45CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)II/271 : TASS Mark IV patches photometric catalog, version 2 (Droege+, 2007)III/227 : General Catalog of galactic Carbon stars, 3d Ed. (Alksnis+ 2001)III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)II/157 : Photoelectric Photometry in Vilnius system (Straizys+ 1989)J/other/A+ARV/20.51 : Rapidly rotating stars (Van Belle, 2012)J/ApJ/732/39 : Rotational velocities of K giant stars (Carlberg+, 2011)J/ApJS/193/17 : IRC+10216 at 293-355GHz (Patel+, 2011)J/A+A/503/913 : Synthetic spectrophotom. for C-rich giants (Aringer+, 2009)J/ApJ/694/1085 : Radii of exoplanet host stars (van Belle+, 2009)J/ApJS/176/276 : PTI calibrator catalog (van Belle+, 2008)J/MNRAS/369/751 : Near-infrared photometry of carbon stars (Whitelock+, 2006)J/ApJS/154/673 : COBE DIRBE Point Source Catalog (Smith+, 2004)J/AJ/126/2048 : NStars project: the Northern Sample. I. (Gray+, 2003)J/A+A/390/967 : Carbon-rich giants in the HR diagram (Bergeat+, 2002)J/A+A/390/511 : Millimetre obs. of carbon stars. II. (Groenewegen+, 2002)J/A+A/369/178 : Effective temperatures of carbon-rich stars (Bergeat+, 2001)J/A+AS/146/217 : Library of Spectra (0.5-2.5um) of Cool Stars (Lancon+ 2000)J/A+A/342/773 : Hot carbon stars B-V colour excess (Bergeat+ 1999)J/A+AS/139/433 : RV and vsini of evolved stars (de Medeiros+ 1999)J/A+A/321/236 : Reddening and fluxes of carbon stars (Knapik+ 1997)J/A+A/310/933 : C isotopic ratio in N- and SC-type stars (Ohnaka+, 1996)J/ApJS/105/419 : Spectral Atlas of Carbon Stars (Barnbaum+ 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/775/45https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/775/45http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/775/45https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/775/45https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/775/45http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/775/45GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/775/45/table1 (Target observed by Palomar Testbed Interferometer)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/775/45/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/775/45/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/775/45/table1?GETtext/xml+votable180.050000true1.15166743.5513060.0055555555555555566/1236 1306 1339 1398 1411 1737 2602 2734 3091 6170 6182 6658 6806 9972 12752 13280 13756 13805 14000 14067 14447 14575 14629 14740 14898 15111 15441 21638 21959 22220 22237 22276 22313 23031 23630 23790 23855 23962 24361 24476 30448https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/775/45?format=asciiOpticalInfrareddefaultJ/ApJ/775/45/table1Target observed by Palomar Testbed InterferometerNameTarget namemeta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintANameAlternative IDmeta.idcharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainV2[1/96]? Visibility points used in fitting {theta}_UD_instr.calibintnullableNV2[1/116]? Number of visibility points available (3{sigma} outliers were discarded)meta.numberintnullabletheta[1.4/4.9]? Resultant uniform disk angular size ({theta}_UD_)masphys.angSizefloatnullablee_theta[0.005/0.2]? Formal fitting error on theta (1)masstat.error;pos.posAngfloatnullableNpNumber of photometric measures used in SED fit (table 3)meta.numberintnullableASimbad column added by the CDSmeta.ref.urlcharf_chi2i: {infinity}meta.codecharchi2? {chi}^2^ fitstat.fit.param;meta.modelledfloatnullableRes? Average residualstat.fit.residualfloatnullableGroupGroup (2)meta.idcharVarVariability type (3)meta.code;src.varcharAmp[0.3/4.7]? Amplitude (3)magphot.magfloatnullableBandBand (V, B, p=photographic or Hp=Hipparcos)meta.code;instr.filtercharAmp1[0.4/2.8]? AFOEV amplitude (4)magsrc.var.amplitudefloatnullableAmp2[0.1/1.7]? HIP amplitudemagsrc.var.amplitudefloatnullableVSXSources within 5.5" from the international Variable Star Index VSXmeta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/775/45/table2Parameters of ellipsoidal fits to angular size data for those stars with semi-orthogonal NS and NW baseline dataSet[Na] Set (a=all baselines) (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar identifiermeta.id;meta.mainchartheta[1.4/3.9] Uniform disk diameter fit with a single-parameter circle ({theta}_circ_)masphys.angSize;meta.modelledfloate_theta[0.004/0.03] theta uncertaintymasstat.error;pos.posAngfloata[1.6/3.96] Major axismasphys.angSizefloate_a[0.02/0.2]? Major axis uncertaintymasstat.errorfloatnullableb[1.4/3.6] Minor axismasphys.angSize;srcfloate_b[0.01/0.2]? Minor axis uncertaintymasstat.errorfloatnullablePA[-78/76] Position angle {phi}degpos.posAnginte_PA[1/42]? PA uncertaintydegstat.errorintnullablechi2e[0.1/3.8] {chi}^2^_{nu},ellipse_ valuestat.fit.chi2floatchi2c[0.3/14.1] {chi}^2^_{nu},circle_ valuestat.fit.chi2floatDelchi2[-0.2/14.1] {Delta}{chi}^2^_{nu}_ valuestat.fit.chi2floatthetaEq[1.6/3.8] Equivalent angular size ({theta}_equiv_=(ab)^0.5^)masphys.angSizefloatRatio[0.9/1.1] Ratio of equivalent angular size to circular angular size ({theta}_equiv_/{theta}_circ_)phys.size;arith.ratiofloatOblat[0.01/0.2] Oblateness (O_ab_=a/b-1)phys.size;arith.ratiofloatE_Oblat[0.01/0.1]? Positive error in Oblatstat.error;stat.maxfloatnullablee_Oblat[0.01/0.2]? Negative error in Oblatstat.errorfloatnullableJ/ApJ/775/45/table3Target photometry used in SED fits (for 41 stars)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar identifiermeta.id;meta.maincharSystPhotometry system (2Mass, Cousins, Johnson or Vilnius)meta.id;photcharBandBandpass (U, V, Rc, Ic, J, H, K, Ks, L, M, P, S, X, Y or Z) (1)instr.bandpasscharmag[1.01/15.4]? Observed magnitude in Band (1)magphot.magfloatnullablee_mag[0.04/2.4]? Magnitude uncertaintymagstat.error;phot.magfloatnullablelambda[1000/12000]? Wavelength (1)nmem.wlintnullableWidth? Bandwidthnminstr.bandwidthintnullableFlux[-36.1/107.2]? Observed flux in lambda (1)Jyphot.fluxfloatnullablee_Flux[0.05/384]? Uncertainty in FluxJystat.error;phot.fluxfloatnullableAuthAuthor(s) of the reference for mag or Fluxmeta.ref;pos.framecharBibCodeBibcode of the reference for mag or Flux when availablemeta.bib.bibcodechar