J/A+A/644/A67ivo://CDS.VizieR/J/A+A/644/A67doi:10.26093/cds/vizier.36440067CDSSreejith A. G.Fossati L.Youngblood A.France K.Ambily S.2021-09-06T08:34:42Z2020-12-01T09:08:13ZCDS support team

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

cds-question@unistra.froptical-observationcatalogslate-type-starsspectroscopyAtmospheric escape is an important factor shaping the exoplanet population and hence drives our understanding of planet formation. Atmospheric escape from giant planets is driven primarily by the stellar X-ray and extreme- ultraviolet (EUV) radiation. Furthermore, EUV and longer wavelength UV radiation power disequilibrium chemistry in the middle and upper atmosphere. Our understanding of atmospheric escape and chemistry, therefore, depends on our knowledge of the stellar UV fluxes. While the far-ultraviolet fluxes can be observed for some stars, most of the EUV range is unobservable due to the lack of a space telescope with EUV capabilities and, for the more distant stars, to interstellar medium absorption. Thus, it becomes essential to have indirect means for inferring EUV fluxes from features observable at other wavelengths. We present here analytic functions for predicting the EUV emission of F, G, K, and M-type stars from the log R'HK activity parameter that is commonly obtained from ground-based optical observations of the Ca II H&K lines. The scaling relations are based on a collection of about 100 nearby stars with published log R'HK and EUV flux values, where the latter are either direct measurements or inferences from high-quality far-ultraviolet (FUV) spectra. The scaling relations presented here return EUV flux values with an accuracy of about three, which is slightly lower than that of other similar methods based on FUV or X-ray measurements.2020A&A...644A..67Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/644/A67CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/644/A67https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/644/A67http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/644/A67https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/644/A67https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/644/A67http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/644/A67GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/644/A67/table2 (Stellar parameters and EUV fluxes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/644/A67/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/644/A67/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/644/A67/table2?GETtext/xml+votable180.050000true67.694991716.14868250.0055555555555555566/322 1875 2472 2497 3979 4444 4651 4881 5009 5413 5522 7763 8357 8790 8843 9403 9483 9662 11856 12644 12983 13743 14525 14682 15174 15345 16652 17266 17341 17425 18496 19912 20328 20701 20746 22300 22590 22626 22878 23191 23230 23538-23539 24151 24178 24227 24831 24924 25444 26183 27018 27088 28400 28548 28664 29196 30015 31374 31751 32509 32561 32848 32930 33510 33630 33813 33849 34905 35079 35532 36697 37573 37954 38461 38807 39364 39693 40692 41432 41591 41724 41763 42248 42459 42760 43228 43911 46076 46632 47550 48274 48652 49103https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/644/A67?format=asciiOpticaldefaultJ/A+A/644/A67/table2Stellar parameters and EUV fluxesSimbadNameSimbad column added by the CDSmeta.idcharNameTarget namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSpTypeMK spectral typesrc.spTypecharVmagAparent V magnitudemagphot.mag;em.opt.VfloatB-VB-V colour indexmagphot.color;em.opt.B;em.opt.VfloatTeffStellar effective temperatureKphys.temperature.effectiveintRadStellar radiussolRadphys.size.radiusfloatDistDistancepcpos.distancefloatlogRpHKmeanMean activity index logR'HKphot.flux;arith.ratiofloatlogRpHKmedMedian activity index logR'HKphot.flux;arith.ratiofloatlogRpHkstddevLogR'HK Standard deviationstat.stdevfloatNobsNumber of observations of LogR'HKmeta.numberintFbolBolometric flux (10^-7^erg/s/cm^2^)1e-10W.m**-2phot.flux.bolfloatFEUVEUV flux in 90-911{AA} (10^-14^erg/s/cm^2^)1e-17W.m**-2phot.flux;em.UVfloatlog(FEUV/Fbol)Flux ratio, log(FEUV/Fbol)phot.flux;arith.ratiofloate_log(FEUV/Fbol)Error of log(FEUV/Fbol)stat.errorfloat_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.main