J/AJ/161/26ivo://CDS.VizieR/J/AJ/161/26doi:10.26093/cds/vizier.51610026CDSCabot S.H.C.Roettenbacher R.M.Henry G.W.Zhao L.Harmon R.O.,Fischer D.A.Brewer J.M.Llama J.Petersburg R.R.Szymkowiak A.E.2022-10-27T08:46:06Z2021-03-26T07:36:55ZCDS support team

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

cds-question@unistra.frexoplanetsg-starsradial-velocityvisible-astronomyspectroscopyphotometryBy controlling instrumental errors to below 10cm/s, the EXtreme PREcision Spectrograph (EXPRES) allows for a more insightful study of photospheric velocities that can mask weak Keplerian signals. Gaussian processes (GP) have become a standard tool for modeling correlated noise in radial velocity data sets. While GPs are constrained and motivated by physical properties of the star, in some cases they are still flexible enough to absorb unresolved Keplerian signals. We apply GP regression to EXPRES radial velocity measurements of the 3.5Gyr old chromospherically active Sun-like star, HD101501. We obtain tight constraints on the stellar rotation period and the evolution of spot distributions using 28 seasons of ground-based photometry, as well as recent Transiting Exoplanet Survey Satellite data. Light-curve inversion was carried out on both photometry data sets to reveal the spot distribution and spot evolution timescales on the star. We find that the >5m/s rms radial velocity variations in HD101501 are well modeled with a GP stellar activity model without planets, yielding a residual rms scatter of 45cm/s. We carry out simulations, injecting and recovering signals with the GP framework, to demonstrate that high-cadence observations are required to use GPs most efficiently to detect low-mass planets around active stars like HD101501. Sparse sampling prevents GPs from learning the correlated noise structure and can allow it to absorb prospective Keplerian signals. We quantify the moderate to high-cadence monitoring that provides the necessary information to disentangle photospheric features using GPs and to detect planets around active stars.2021AJ....161...26Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/161/26CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005)J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)J/A+A/469/309 : Chromospheric activity in late-type stars (Cincunegui+,2007)J/A+A/506/303 : CoRoT-7 radial velocities (Queloz+, 2009)J/ApJ/746/101 : Diameters and temperatures of AFG stars (Boyajian+, 2012)J/A+A/552/A16 : Limb-darkening for CoRoT, Kepler, Spitzer II. (Claret+,2013)J/A+A/551/A79 : Radial velocity periodic variations {tau}Ceti (Tuomi+, 2013)J/A+A/564/A125 : AGN Torus model comparison of AGN in CDFS (Buchner+, 2014)J/ApJS/210/5 : The twenty-five year Lick planet search (Fischer+, 2014)J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)J/A+A/608/A35 : K2-18 HARPS time-series (Cloutier+, 2017)J/MNRAS/474/2094 : Inferring probabilistic stellar rotation per (Angus+, 2018)J/A+A/618/A20 : Limb-darkening for TESS, Kepler, Corot, MOST (Claret, 2018)J/A+A/639/A50 : HD 164922 d HARPS-N time series (Benatti+, 2020)J/A+A/635/A13 : HD41248 Radial velocities & activity indicator (Faria+,2020)J/AJ/159/187 : First RVs with EXPRES spectrograph: 51Peg (Petersburg+,2020)J/A+A/639/A77 : Proxima Cen RV, FWHM and fluxes (Suarez Mascareno+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/161/26https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/161/26http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/161/26https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/161/26https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/161/26http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/161/26GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/161/26/table5RV measurements and activity indicatorsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[18237/19034] Heliocentric Julian Date; JD-2440000dtime.epochdoubleRVel[-10.9/14.1] Radial velocitym/sphys.veloc;pos.heliocentricfloate_RVel[0.004/1] Error on RVelm/sstat.error;phys.velocfloatEWHa[0.91/2.03]? H{alpha} equivalent width0.1nmspect.line.eqWidthfloatnullableBIS[-78/83]? Bisector spanm/sphys.velocfloatnullableFWMH[572/7646]? FWMH of th CCFm/sphys.velocfloatnullableJ/AJ/161/26/table6Summary of APT photometric observations for HD101501recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeas-b[1992/2019] Year of the season beginningyrtime.epochintSeas-e[1993/2020] Year of the season endingyrtime.epochintNobs[37/146] Number of observations during seasonmeta.numberintHJD-b[49095/58802] Heliocentric julian date of the beginning of observation; JD-2400000dtime.epochintHJD-e[49161/59022] Heliocentric julian date of the end of observation; JD-2400000dtime.epochintSigma[0.002/0.008] APT magnitude observedmagphot.mag;em.optdoubleMeanSeasonal meanmagphot.mag;em.optcharPer[12.2/16.8] Perioddtime.periodfloat