J/ApJS/211/9ivo://CDS.VizieR/J/ApJS/211/9doi:10.26093/cds/vizier.22110009CDSLoyd R.O.P.France K.2021-08-04T12:02:32Z2014-04-16T14:22:56ZCDS support team

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

cds-question@unistra.frmultiple-starsspectroscopyultraviolet-astronomysolar-system-planetsstellar-flaresVariations in stellar flux can potentially overwhelm the photometric signal of a transiting planet. Such variability has not previously been well-characterized in the ultraviolet lines used to probe the inflated atmospheres surrounding hot Jupiters. Therefore, we surveyed 38 F-M stars for intensity variations in four narrow spectroscopic bands: two enclosing strong lines from species known to inhabit hot Jupiter atmospheres, C.II {lambda}{lambda}1334, 1335 and SiIII{lambda}1206; one enclosing SiIV {lambda}{lambda}1393, 1402; and 36.5{AA} of interspersed continuum. For each star/band combination, we generated 60s cadence lightcurves from archival Hubble Space Telescope Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph time-tagged photon data. Within these lightcurves, we characterized flares and stochastic fluctuations as separate forms of variability. Flares: we used a cross-correlation approach to detect 116 flares. These events occur in the time-series an average of once per 2.5hr, over 50% last 4 minutes or less, and most produce the strongest response in SiIV. If the flare occurred during a transit measurement integrated for 60 minutes, 90/116 would destroy the signal of an Earth, 27/116 Neptune, and 7/116 Jupiter, with the upward bias in flux ranging from 1% to 109% of quiescent levels. Fluctuations: photon noise and underlying stellar fluctuations produce scatter in the quiescent data. We model the stellar fluctuations as Gaussian white noise with standard deviation {sigma}_x_. Maximum likelihood values of {sigma}_x_ range from 1% to 41% for 60s measurements. These values suggest that many cool stars will only permit a transit detection to high confidence in ultraviolet resonance lines if the radius of the occulting disk is >~1R_J_. However, for some M dwarfs this limit can be as low as several R_{oplus}_.2014ApJS..211....9Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/211/9CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)V/130 : Geneva-Copenhagen Survey of Solar neighbourhood III (Holmberg+, 2009)III/244 : Catalog of Stellar Rotational Velocities (Glebocki+ 2005)II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)V/73 : Emission-Line Stars of the Orion Population (Herbig+ 1988)J/ApJ/754/69 : UV spectroscopy of solar-mass stars (Linsky+, 2012)J/MNRAS/420/1590 : Abundances of classical Cepheids (Acharova+, 2012)J/MNRAS/410/190 : Young runaway stars within 3kpc (Tetzlaff+, 2011)J/A+A/532/A10 : RACE-OC project. II. (Messina+, 2011)J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)J/A+A/526/A99 : Metal-poor solar-type stars spectro. & masses (Sousa+, 2011)J/PASP/123/412 : Exoplanet Orbit Database (Wright+, 2011)J/ApJ/731/8 : Multiple star formation in Taurus-Auriga (Kraus+, 2011)J/AZh/88/34 : Long-term (1984-2008) JHKLM phot. (Shenavrin+, 2011)J/MNRAS/408/475 : HATNet Pleiades Rotation Period Catalogue (Hartman+, 2010)J/MNRAS/403/1949 : UBV(RcIc)JHK photometry of HIP nearby stars (Koen+, 2010)J/A+A/520/A15 : RACE-OC project: YSOs within 100pc (Messina+, 2010)J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)J/ApJ/705/1416 : M7-M9.5 dwarfs <20pc (Reiners+, 2009)J/ApJ/704/975 : Rotational velocities for M dwarfs (Jenkins+, 2009)J/ApJ/704/531 : The coevality of young binary systems (Kraus+, 2009)J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)J/ApJ/694/1085 : Radii of exoplanet host stars (van Belle+, 2009)J/ApJS/181/62 : Survey of young solar analogs (Metchev+, 2009)J/other/A+ARV/17.251 : Stars observed with Doppler imaging (Strassmeier, 2009)J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)J/AJ/133/2524 : Spectra of young nearby stars (White+, 2007)J/ApJS/168/297 : Stellar parameters of nearby cool stars (Takeda+, 2007)J/MNRAS/374/664 : Stellar parameters in MILES library (Cenarro+, 2007)J/AJ/132/161 : NStars project: The southern sample. I. (Gray+, 2006)J/A+A/460/695 : Associations Containing Young stars (Torres+, 2006)J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)J/ApJ/581/1194 : Taurus-Auriga PMS stars ages and Teff (Palla+, 2002)J/MNRAS/328/45 : Late-type stars members of young groups (Montes+, 2001)J/A+A/379/976 : Moving groups late-type stars EWs + fluxes (Montes+ 2001)J/A+AS/144/469 : Delta Scuti stars (Rodriguez+, 2000)J/A+A/352/555 : Fundamental parameters of stars (Allende Prieto+, 1999)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/211/9https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/211/9http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/211/9https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/211/9https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/211/9http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/211/9GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/211/9/table1 (Properties of the stars in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/211/9/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/211/9/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/211/9/table1?GETtext/xml+votable180.050000true2.29462559.149750.0055555555555555566/322 496 1114 1168 1170 3005 3138 4095 4444 5929 6226 7763 10255 11856 12644 12983 13301 13743 15633 18496 24151 28548 28664 30878 33804 37012 38363 38687 40941 41460 41591 44226 44921 46076 46632 48274https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/211/9?format=asciiUVdefaultJ/ApJS/211/9/table1Properties of the stars in the sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar identifiermeta.id;meta.mainprimaryf_Star[j] j: indicates unresolved binary system; see Section 2.meta.codechar2MASS2MASS Designation if any (JHHMMSSss+DDMMSSs)meta.idcharSpTypeMK spectral type (1)src.spTypecharr_SpTypeReference(s) for SpType (see refs.dat file)meta.ref;pos.framecharOTypeOther classification type (3)meta.notecharr_OTypeReference(s) for OType (see refs.dat file)meta.notecharNp[1/4]? Number of known planetsmeta.numberintnullabler_NpReference(s) for Np (see refs.dat file)meta.ref;pos.framecharAge[2/10500]? Estimated stellar ageMyrtime.agefloatnullablef_Age[ aefl] Flag(s) on Age (4)meta.codecharE_Age? Upper limit uncertainty in AgeMyrstat.error;stat.maxintnullablee_Age? Lower limit uncertainty in Age (5)Myrstat.error;time.agefloatnullabler_AgeReference(s) for Age (see refs.dat file)meta.ref;pos.framecharl_Prot[<~] Limit or approximation flag on Protmeta.code.errorcharProt[0.4/286]? Stellar rotational perioddtime.perioddoublenullablef_Prot[ bcegh] Flag(s) on Prot (4)meta.codechare_Prot[0.000005/98]? Uncertainty in Protdstat.errordoublenullabler_ProtReference(s) on Prot (see refs.dat file)meta.ref;pos.framecharM[0.08/7.7] Stellar masssolMassphys.massfloatf_M[abm] Flag on M (4)meta.codecharE_M? Upper limit uncertainty in MsolMassstat.error;stat.maxfloatnullablee_M? Lower limit uncertainty in M (5)solMassstat.errorfloatnullabler_MReference(s) on M (see refs.dat file)meta.ref;pos.framecharR[0.1/71]? Stellar radiussolRadphys.size.radiusfloatnullablef_R[ abdi] Flag(s) on R (4)meta.codechare_R[0.004/11]? Uncertainty in RsolRadstat.errorfloatnullabler_RReference(s) on R (see refs.dat file)meta.refcharTeff[2564/6959] Effective stellar temperatureKphys.temperature.effectiveintf_Teff[a] Flag on Teff (4)meta.codecharE_Teff? Upper limit uncertainty in TeffKstat.error;stat.maxintnullablee_Teff? Lower limit uncertainty in Teff (5)Kstat.error;phys.temperature.effectiveintnullabler_TeffReference(s) on Teff (see refs.dat file)meta.ref;pos.framecharlog(g)[1.6/5.3]? Log of stellar surface gravitylog(cm.s**-2)phys.gravityfloatnullablef_log(g)[ abe] Flag(s) on log(g) (4)meta.codechare_log(g)? Uncertainty in log(g)log(cm.s**-2)stat.errorfloatnullabler_log(g)Reference(s) for log(g) (see refs.dat file)meta.ref;pos.framecharvsini[0.3/162.5]? Projected stellar equatorial velocitykm/sphys.velocfloatnullablef_vsini[ abde] Flag(s) on vsini (4)meta.codechare_vsini? Uncertainty in vsinikm/sstat.error;phys.veloc.rotatfloatnullabler_vsiniReference(s) for vsini (see refs.dat file)meta.refcharL[0.0003/5291.4] Stellar luminositysolLumphys.luminositydoublee_L[0.00024]? Uncertainty in LsolLumstat.errordoublenullabler_LReference for L (see refs.dat file)meta.refchar_RAPositions from 2MASS names or from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from 2MASS names or from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/ApJS/211/9/table2Catalog of observationsNexp[2/47]? Number of exposures takenmeta.numberintnullableTobs? Total "observed" time (3)stime.intervaldoublenullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNum[1/42] Dataset number (1)meta.bib.figintStarStar identifiermeta.id;meta.mainf_StarFor multiple grating observationsmeta.codecharInstSpectrograph used (COS or STIS)meta.id;instrcharGratingGrating used (E140M, G130M or G140L)instr.setupcharDateUT date/time of observation startstime.start;obsnullableTexp[208.9/5460.2] Total exposure time (2)stime.duration;obs.exposuredoubleATexp? Sum of all exposure timesstime.duration;obs.exposuredoublenullablePObs? Percentage observed (4)%meta.notefloatnullableTmax? Longest block of time (5)stime.intervaldoublenullableBandsSpectral bands (6)em.wlcharJ/ApJS/211/9/var_statsVariability statistics in CII (table4), SiIII (table5), SiIV (table6), and Continuum (table7)l_RsigLimit flag on Rsigmeta.code.errorcharIonLine (CII, SiIII, SiIV) or cont=Continuum observedmeta.id;spect.linecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar identifiermeta.id;meta.mainf_StarFlag on Star (1)meta.codechar<F>[1/249700]? Mean value of the lightcurve in 10^-17^erg/s/cm^2^1e-20W.m**-2phot.flux;em.UVdoublenullablee_<F>[1/4000]? <F> uncertainty1e-20W.m**-2stat.errorfloatnullablel_SigXLimit flag on SigXmeta.code.errorcharSigX[0.006/1]? Mean-normalized excess noise {sigma}_x_ at 60s cadencesrc.var.amplitudedoublenullableE_SigX[0.001/0.2]? SigX positive errorstat.error;stat.maxfloatnullablee_SigX[0.002/0.2]? SigX negative errorstat.errorfloatnullableRsig[0.1/31]? Radius of potential planet (2)(7.1492x10+7m)phys.size.radiusfloatnullableE_Rsig[0.009/8]? Rsig positive error(7.1492x10+7m)stat.error;stat.maxfloatnullablee_Rsig[0.009/13]? Rsig negative error(7.1492x10+7m)stat.errorfloatnullablef_RsigFlag on Rsig (1)meta.codecharNf[0/28]? Number of flares identifiedmeta.numberintnullableDC[0/0.4]? Fraction of lightcurve points encompassed by flares (duty cycle)stat.fit.paramfloatnullableEWp[3/691]? Min photometric equivalent width of a detectable flare given the lightcurve scattersstat.fit.paramfloatnullableJ/ApJS/211/9/refsReferences (for table 1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference codemeta.noteintBibCodeBibcodemeta.bib.bibcodecharAut? Author's name(s)meta.bib.authorcharCommCommentmeta.notechar