J/A+A/672/A144ivo://CDS.VizieR/J/A+A/672/A144doi:10.26093/cds/vizier.36720144CDSCanocchi G.Malavolta L.Pagano I.Barragan O.Piotto G.Aigrain S.,Desidera S.Grziwa S.Cabrera J.Rauer H.2024-11-06T20:03:23Z2023-04-14T13:43:22ZCDS support team

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

cds-question@unistra.frastronomical-modelsTo date, stellar activity is one of the main limitations in detecting small exoplanets via the transit photometry technique. Since this activity is enhanced in young stars, traditional filtering algorithms may severely under-perform in detecting such exoplanets, with shallow transits often obscured by the photometric modulation of the light curve. This paper aims to compare the relative performances of four algorithms developed by independent research groups specifically for the filtering of activity in the light curves of young active stars, prior to the search for planetary transit signals: Notch and LOCoR (N&L), Young Stars Detrending (YSD), K2 Systematics Correction (K2SC) and VARLET. We include in the comparison also the two best-performing algorithms implemented in the Wotan package, namely the Tukey's biweight and the Huber Spline algorithms. For this purpose, a series of injection-retrieval tests of planetary transits of different types, from Jupiter down to Earth-sized planets, moving both on circular and eccentric orbits, have been performed. These experiments were carried out over a set of 100 realistically simulated light curves of both quiet and active solar-like stars (i.e., F and G-type) that will be observed by the ESA space telescope PLATO (PLAnetary Transits and Oscillations of stars), to be launched in 2026. From the experiments for transit detection, it was found that N&L is the best choice in many cases, since it misses the lowest number of transits. However, this algorithm under-performs if the planetary orbital period closely matches the stellar rotation period, especially in the case of small planets for which the biweight and VARLET algorithms works better. Moreover for light curves with a large number of data-points, the combined results of two algorithms, YSD and Huber Spline, yield the highest recovery percentage. Filtering algorithms allow us to obtain a very precise estimate of the orbital period and the mid-transit time of the detected planets, while the planet-to-star radius is under-estimated most of the time, especially in the case of grazing transits or eccentric orbits. A refined filtering taking into account the presence of the planet is then compulsory for a proper planetary characterization.2023A&A...672A.144Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/672/A144CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/672/A144https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/672/A144http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/672/A144https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/672/A144https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/672/A144http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/672/A144GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/672/A144/tableb1Input parameters for the 100 simulated PLATO light curves of the quiet samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLCLight curve numbermeta.idintIDStellar ID in Aigrain et al. (2015MNRAS.450.3211A)meta.id;meta.mainintAActivity level relative to the solarSunphot.flux;arith.ratiofloatProtStellar rotational perioddtime.periodfloatTeffEffective temperatureKphys.temperature.effectivedoubleloggSurface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicity ([Fe/H])phys.abund.ZfloatrhoStellar densityg.cm**-3phys.densitydoubleu1Limb darkening coefficientphot.limbDarkdoubleu2Limb darkening coefficientphot.limbDarkdoubleplotShow the light curvemeta.ref.urlcharFileNameName of the light curve file in subdirectory lcmeta.id;meta.filecharJ/A+A/672/A144/tableb2Input parameters for the 100 simulated PLATO light curves of the active samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLCLight curve numbermeta.idintIDStellar ID in Aigrain et al. (2015MNRAS.450.3211A)meta.id;meta.mainintAActivity level relative to the solarSunphot.flux;arith.ratiofloatProtStellar rotational perioddtime.periodfloatTeffEffective temperatureKphys.temperature.effectivedoubleloggSurface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicity ([Fe/H])phys.abund.ZfloatrhoStellar densityg.cm**-3phys.densitydoubleu1Limb darkening coefficientphot.limbDarkdoubleu2Limb darkening coefficientphot.limbDarkdoubleplotShow the light curvemeta.ref.urlcharFileNameName of the light curve file in subdirectory lcmeta.id;meta.filechar