J/A+A/678/A2ivo://CDS.VizieR/J/A+A/678/A2doi:10.26093/cds/vizier/bc-n6/lcCDSCretignier M.Dumusque X.Aigrain S.Pepe F.2026-07-01T14:00:58Z2023-09-28T08:49:33ZCDS support team

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

cds-question@unistra.frstandard-starsradial-velocityvisible-astronomyThe detection of Earth-like planets with the radial velocity (RV) method is extremely challenging today due to the presence of non-Doppler signatures such as stellar activity and instrumental signals that mimic and hide the signals of exoplanets. In a previous paper, we presented the YARARA pipeline, which implements corrections for telluric absorption, stellar activity, and instrumental systematics at the spectral level, and then it extracts line-by-line (LBL) RVs with a significantly better precision than standard pipelines. In this paper, we demonstrate that further gains in RV precision can be achieved by performing principal component analysis (PCA) decomposition on the LBL RVs. The mean-insensitive nature of PCA means that it is unaffected by true Doppler shifts, and thus can be used to isolate and correct nuisance signals other than planets. We analysed the data of 20 intensively observed HARPS targets by applying our PCA approach on the LBL RVs obtained by YARARA. The first principal components show similarities across most of the stars and correspond to newly identified instrumental systematics for which we can now correct. For several targets, this results in an unprecedented RV root-mean-square of around 90cm/s over the full lifetime of HARPS. We used the corrected RVs to confirm a previously published 120-day signal around 61 Vir, and to detect a super-Earth candidate (K~60+/-6cm/s, msini=6.6+/-0.7M+{Earth}_) around the G6V star HD 20794, which spends part of its 600-day orbit within the habitable zone of the host star. This study highlights the potential of LBL PCA to identify and correct hitherto unknown, long-term instrumental effects and thereby extend the sensitivity of existing and future instruments towards the Earth analogue regime.2023A&A...678A...2Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A2CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/678/A2https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/678/A2http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/678/A2https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/678/A2https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/678/A2http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/678/A2GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/678/A2/hd109200HD 109200 DRS, YV1 and YV2 RV time seriesRVDRSDRS radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVDRSDRS radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV1YV1 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV1YV1 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV2YV2 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV2YV2 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoublectm-shell1Unscaled linear predictor shell 1stat.fit.paramdoublectm-shell2Unscaled linear predictor shell 2stat.fit.paramdoublectm-shell3Unscaled linear predictor shell 3stat.fit.paramdoublectm-shell4Unscaled linear predictor shell 4stat.fit.paramdoublectm-shell5Unscaled linear predictor shell 5stat.fit.paramdoublectm-slice1Unscaled linear predictor slice 1stat.fit.paramdoublectm-slice2Unscaled linear predictor slice 2stat.fit.paramdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[0/356] Index of the tablemeta.idintTimeTime (JD-2400000)dtime.epochdoubleJ/A+A/678/A2/hd115617HD 115617 DRS, YV1 and YV2 RV time seriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[0/200] Index of the tablemeta.idintctm-lbl2Unscaled linear predictor lbl 2stat.fit.paramdoubleTimeTime (JD-2400000)dtime.epochdoubleRVDRSDRS radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVDRSDRS radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV1YV1 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV1YV1 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV2YV2 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV2YV2 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoublectm-shell1Unscaled linear predictor shell 1stat.fit.paramdoublectm-shell2Unscaled linear predictor shell 2stat.fit.paramdoublectm-shell3Unscaled linear predictor shell 3stat.fit.paramdoublectm-shell4Unscaled linear predictor shell 4stat.fit.paramdoublectm-shell5Unscaled linear predictor shell 5stat.fit.paramdoublectm-slice1Unscaled linear predictor slice 1stat.fit.paramdoublectm-slice2Unscaled linear predictor slice 2stat.fit.paramdoublectm-color1Unscaled linear predictor color 1stat.fit.paramdoublectm-color2Unscaled linear predictor color 2stat.fit.paramdoublectm-lbl1Unscaled linear predictor lbl 1stat.fit.paramdoubleJ/A+A/678/A2/hd192310HD 192310 DRS, YV1 and YV2 RV time seriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[0/318] Index of the tablemeta.idintTimeTime (JD-2400000)dtime.epochdoubleRVDRSDRS radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVDRSDRS radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV1YV1 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV1YV1 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV2YV2 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV2YV2 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoublectm-shell1Unscaled linear predictor shell 1stat.fit.paramdoublectm-shell2Unscaled linear predictor shell 2stat.fit.paramdoublectm-shell3Unscaled linear predictor shell 3stat.fit.paramdoublectm-shell4Unscaled linear predictor shell 4stat.fit.paramdoublectm-shell5Unscaled linear predictor shell 5stat.fit.paramdoublectm-shell6Unscaled linear predictor shell 6stat.fit.paramdoublectm-shell7Unscaled linear predictor shell 7stat.fit.paramdoublectm-slice1Unscaled linear predictor slice 1stat.fit.paramdoublectm-slice2Unscaled linear predictor slice 2stat.fit.paramdoublectm-color1Unscaled linear predictor color 1stat.fit.paramdoublectm-lbl1Unscaled linear predictor lbl 1stat.fit.paramdoubleJ/A+A/678/A2/hd20794HD 20794 DRS, YV1 and YV2 RV time seriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIndex[0/467] Index of the tablemeta.idintTimeTime (JD-2400000)dtime.epochdoubleRVDRSDRS radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVDRSDRS radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV1YV1 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV1YV1 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoubleRVYV2YV2 radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVYV2YV2 radial velocity uncertainty + 0.70m/s added quad.m/sstat.errordoublectm-shell1Unscaled linear predictor shell 1stat.fit.paramdoublectm-shell2Unscaled linear predictor shell 2stat.fit.paramdoublectm-shell3Unscaled linear predictor shell 3stat.fit.paramdoublectm-shell4Unscaled linear predictor shell 4stat.fit.paramdoublectm-shell5Unscaled linear predictor shell 5stat.fit.paramdoublectm-slice1Unscaled linear predictor slice 1stat.fit.paramdoublectm-slice2Unscaled linear predictor slice 2stat.fit.paramdoublectm-color1Unscaled linear predictor color 1stat.fit.paramdoublectm-color2Unscaled linear predictor color 2stat.fit.paramdoublectm-color3Unscaled linear predictor color 3stat.fit.paramdoublectm-lbl1Unscaled linear predictor lbl 1stat.fit.paramdoublectm-lbl2Unscaled linear predictor lbl 2stat.fit.paramdoublectm-lbl3Unscaled linear predictors lbl 3stat.fit.paramdoublectm-lbl4Unscaled linear predictors lbl 4stat.fit.paramdouble