J/A+A/696/A27ivo://CDS.VizieR/J/A+A/696/A27doi:10.26093/cds/vizier.36960027CDSJeffers S.V.Barnes J.R.Schoefer P.Reffert S.Bejar V.J.S.,Quirrenbach A.Reiners A.Shan Y.Zapatero Osorio M.R.Fuhrmeister B.,Amado P.J.Caballero J.A.Ribas I.Cardona Guillen C.Del Sordo F.,Fernandez M.Garcia-Lopez A.Guijarro A.Hatzes A.P.Lafarga M.,Lodieu N.Kuerster M.Molaverdikhani K.Montes D.Morales J.C.2025-10-13T20:01:23Z2025-04-01T11:42:36ZCDS support team

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

cds-question@unistra.frmultiple-starsm-starsexoplanetsradial-velocityCurrent exoplanet surveys are focused on detecting small exoplanets orbiting in the liquid-water habitable zones of their host stars. Despite recent significant advancements in instrumentation, the main limitation in detecting these exoplanets is the intrinsic variability of the host star itself. Our aim is to investigate the wavelength dependence of high-precision radial velocities (RV), as stellar activity induced RVs should exhibit a wavelength dependence while the RV variation due to an orbiting planet will be wavelength independent. We used the chromatic index (CRX) to quantify the slope of the measured RVs as a function of logarithmic wavelength of the full CARMENES guaranteed time observations (GTO) data set spanning more than eight years of observations of over 350 stars. We investigated the dependence of the CRX in the full Carmenes GTO sample on 24 stellar activity indices in the visible and near-infrared channels of the CARMENES spectrograph and each star;s stellar parameters. We also present an updated convective turnover time scaling for the calculation of the stellar Rossby number for M dwarfs. Our results show that approximately 17% of GTO stars show a strong or a moderate correlation between the CRX and RV. We can improve the measured RVs by a factor of up to nearly 4 in terms of the root mean square (rms) by subtracting the RV predicted by the CRX-RV correlation from the measured RVs. Mid-M dwarfs with moderate rotational velocities and moderate CRX-gradients, with quasi-stable activity features, have the best rms improvement factors. We conclude that the CRX is a powerful diagnostic in mitigation of stellar activity and the search for low mass rocky planets.2025A&A...696A..27Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/696/A27CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/696/A27https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/696/A27http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/696/A27https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/696/A27https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/696/A27http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/696/A27GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/696/A27/tableb1 (stars used for our analysis)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/696/A27/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/696/A27/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/696/A27/tableb1?GETtext/xml+votable180.050000true1.295371745.78656690.0055555555555555566/22 131 250 497 546 624 725 811 1033 1628 1672 1793 1822 1875 1938 2515 2545 2737 2747 3035 3374 3658 3682 3715 3791 3900 4033 4145 4366 4444 4518 4651 4867 5000 5212 5241 5420 5488 5534 5590 6552 6672 6809 6894 7103 7264 7395 7471 7510 7605 7611 8023 8032 8123 8331 8394 8562 8627 8843 9188 9529 9597 9750 10037 10149 10169 10225 10278 11044 11255 11636 11974 12128 12184 12191 12621 12732 12865 13567 13688 13743 13875 13912 14277 14395 14709 14803 14858 14993 15078 15346 15355 15431 15548 15598 15602 15629 15635 15748 15763 15792 15960 15997 16117 16266 16754 16758 17020 17271 17302 17348 17358 17412 17870 18195 18496 18553 18666 18726 18761 18789 18942 19064 19131 19306 19352 19466 19516 19791 20023 20100 20311 20459 20795 20839 20896 21051 21151 21171 21427 21747-21748 21953 21986 22277 22289 22309 22559 22626 22661 22709 22807 22942 23443 23731 23735 23867 23910 24213 25363 25512 25989 26538 26560 26583 26699 26706 26768 26772 26972 27201 27392 27459 27462 27730 27787 28279 28341 28343 28548 28646 28955 29170 29684 30345 30429 30455 30490 30613 30771 30833 31014 31191 31767 31781 31983 32033 32093 32115 32335 32491 32730 32753 40250 40436 40513 40623 40941 44378 44541 44921 44937 44967 48274 48500 48801 48906 49101https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/696/A27?format=asciidefaultJ/A+A/696/A27/tableb1stars used for our analysisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKarmnCARMENES star namemeta.id;meta.maincharNameAlternative star namemeta.idcharSpTypeSpectral Typesrc.spTypecharNobsNumber of observationsmeta.numberintTeff? Stellar effective temperatureKphys.temperature.effectiveintnullableR? Stellar radiussolRadphys.size.radiusdoublenullableM? Stellar masssolMassphys.massdoublenullablevsini? Rotational velocitykm/sphys.veloc.rotatfloatnullabler_vsiniReference of vsini (1)meta.refcharpEWHa? Halpha pseudo-equivalent width0.1nmspect.line.eqWidthfloatnullableB? Average magnetic field strengthGphys.magField;phys.atmol.collStrengthintnullableV-Ks? V-Ks colour indexmagphot.color;em.opt.V;em.IR.Kfloatnullablelogtau? Log Convective turnover timelog(s)time.scaledoublenullableTiO7050? TiO {lambda}7050{AA} equivalent width0.1nmspect.line.eqWidthdoublenullableProt? Stellar rotation perioddtime.perioddoublenullabler_ProtReference stellar rotation period (2)meta.ref;pos.framecharCRXl? Chromatic index CRX lengthm/sspect.indexdoublenullableCRXs? Chromatic index CRX slopespect.indexfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullable_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