J/AJ/163/168ivo://CDS.VizieR/J/AJ/163/168doi:10.26093/cds/vizier.51630168CDSWinters J.G.Cloutier R.Medina A.A.Irwin J.M.Charbonneau D.,Astudillo-Defru N.Bonfils X.Howard A.W.Isaacson H.Bean J.L.,Seifahrt A.Teske J.K.Eastman J.D.Twicken J.D.Collins K.A.,Jensen E.L.N.Quinn S.N.Payne M.J.Kristiansen M.H.Spencer A.,Vanderburg A.Zechmeister M.Weiss L.M.Wang S.X.Wang G.Udry S.,Terentev I.A.Sturmer J.Stefansson G.Shporer A.Shectman S.,Sefako R.Schwengeler H.M.Schwarz R.P.Scarsdale N.Rubenzahl R.A.,Roy A.Rosenthal L.J.Robertson P.Petigura E.A.Pepe F.Omohundro M.,Murphy J.M.A.Murgas F.Mocnik T.Montet B.T.Mennickent R.Mayo A.W.,Massey B.Lubin J.Lovis C.Lewin P.Kasper D.Kane S.R.Jenkins J.M.,Huber D.Horne K.Hill M.L.Gorrini P.Giacalone S.Fulton B.,Forveille T.Figueira P.Fetherolf T.Dressing C.Diaz R.F.,Delfosse X.Dalba P.A.Dai F.Cortes C.C.Crossfield I.J.M.Crane J.D.,Conti D.M.Collins K.I.Chontos A.Butler R.P.Brown P.Brady M.,Behmard A.Beard C.Batalha N.M.Almenara J.-M.2025-02-24T08:59:58Z2022-05-11T08:24:48ZCDS support team

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

cds-question@unistra.frm-starsexoplanetsvisible-astronomyspectroscopyphotometryradial-velocityLTT1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86pc. The primary star LTT1445A (0.257M{sun}) is known to host the transiting planet LTT1445Ab with an orbital period of 5.36days, making it the second-closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using Transiting Exoplanet Survey Satellite data, we present the discovery of a second planet in the LTT1445 system, with an orbital period of 3.12days. We combine radial-velocity measurements obtained from the five spectrographs, Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, High Accuracy Radial Velocity Planet Searcher, High-Resolution Echelle Spectrometer, MAROON-X, and Planet Finder Spectrograph to establish that the new world also orbits LTT1445A. We determine the mass and radius of LTT1445Ab to be 2.87{+/-}0.25M{Earth} and 1.304_-0.060_^+0.067^R{Earth}, consistent with an Earth-like composition. For the newly discovered LTT 1445Ac, we measure a mass of 1.54_-0.19_^+0.20^M{Earth} and a minimum radius of 1.15R{Earth}, but we cannot determine the radius directly as the signal-to-noise ratio of our light curve permits both grazing and nongrazing configurations. Using MEarth photometry and ground-based spectroscopy, we establish that star C (0.161M{sun}) is likely the source of the 1.4day rotation period, and star B (0.215M{sun}) has a likely rotation period of 6.7days. We estimate a probable rotation period of 85days for LTT1445A. Thus, this triple M-dwarf system appears to be in a special evolutionary stage where the most massive M dwarf has spun down, the intermediate mass M dwarf is in the process of spinning down, while the least massive stellar component has not yet begun to spin down.2022AJ....163..168Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/163/168CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)J/ApJ/757/112 : Stellar diameters. II. K and M-stars (Boyajian+, 2012)J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)J/A+A/575/A119 : HARPS RV and stellar activity (Astudillo-Defru+, 2015)J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)J/A+A/584/A72 : Transiting rocky planet at 6.5pc from the Sun (Motalebi+ 2015)J/AJ/152/141 : Solar neighborhood. XXXVII. RVs for M dwarfs (Benedict+, 2016)J/A+A/585/A134 : HD1461, HD40307, and HD204313 radial velocities (Diaz+, 2016)J/ApJ/821/93 : Rotation & Galactic kinematics of mid M dwarfs (Newton+, 2016)J/A+A/600/A13 : HARPS Mdwarf sample magnetic activity (Astudillo-Defru+, 2017)J/ApJ/834/17 : Mass & radius of planets, moons, low mass stars (Chen+, 2017)J/A+A/600/A30 : Limb-darkening for TESS satellite (Claret, 2017)J/A+A/608/A35 : K2-18 HARPS time-series (Cloutier+, 2017)J/ApJ/834/85 : H{alpha} emission in nearby M dwarfs (Newton+, 2017)J/MNRAS/474/2094 : Inferring probabilistic stellar Prots (Angus+, 2018)J/A+A/618/A142 : Radial velocity for GJ 1132 (Bonfils+, 2018)J/AJ/155/265 : Solar neighborhood. XLIV. RECONS discoveries (Henry+, 2018)J/AJ/155/180 : A catalog of cool dwarf targets for the TESS (Muirhead+, 2018)J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)J/A+A/629/A111 : L 98-59 (TOI 175) HARPS observations (Cloutier+, 2019)J/A+A/628/A39 : Radial velocities of GJ 357 (Luque+, 2019)J/AJ/160/3 : Radial velocities M-dwarf LTT3780 with HARPS (Cloutier+, 2020)J/AJ/160/22 : TOI-1235 Rvel & optical spectroscopy (Cloutier+, 2020)J/A+A/642/A236 : GJ 3473 (TOI-488) radial velocity curve (Kemmer+, 2020)J/AJ/159/290 : RVs of 12 spectroscopic binaries M-dwarfs (Winters+, 2020)J/AJ/162/79 : HARPS radial velocity follow up of TOI-1634 (Cloutier+, 2021)J/AJ/161/23 : Rvel & light curve of low mass star TOI 540 (Ment+, 2021)J/AJ/161/63 : Mdwarfs masses 0.1<~M/M{sun}<~0.3 within 15pc (Winters+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/163/168https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/163/168http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/163/168https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/163/168https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/163/168http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/163/168GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/163/168/table1Radial velocities for LTT1445AInstInstrument used (1)instr.setupcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2458546/2459190] Barycentric Julian Date of mid-exposure, TDB systemdtime.epochdoubleRVel[-5464/5.08] Barycentric radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVel[0.1/3] Uncertainty in RVelm/sstat.error;spect.dopplerVelocfloatJ/AJ/163/168/fig2a*MEarth light curve data for of LTT1445ArecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2458528/2459495] Barycentric Julian Date at mid-exposuredtime.epochdoubleindexedDmag[-0.8/1.61] Differential magnitudemagphot.mag;arith.diffdoublee_Dmag[0.002/0.2] Uncertainty in differential magnitudemagstat.error;phot.mag;arith.diffdoubleTexp[4.034] Exposure timestime.duration;obs.exposurefloatmag0[-3.98/0.25] Frame magnitude zero point offsetmagphot.mag;arith.zpfloatFWHM[-1/5.26] FWHM of stellar images (1)pixphys.angSizefloatEll[0.005/0.37] Ellipticity of stellar images (1)src.ellipticityfloatAirmass[1.02/2.06] Airmass at mid-exposureobs.airMassdoubleX[625/1427] X pixel coordinate of starpixpos.cartesian.xdoubleY[756/1288] Y pixel coordinate of starpixpos.cartesian.ydoubleAngle[-180/0.04] Angle relative to reference imagedeginstr.offsetfloatSky[1.77/4677] Local sky background levelinstr.skyLeveldoublePeak[691/21273] Peak counts in object, including skymeta.numberintSeg[1/2] Segment number (2)meta.idintVers[4] Instrument version numbermeta.number;instrintStatus[0/2] Realtime status flag (3)meta.code.errorintFlags[0] Flags (4)meta.code.errorintCM[-0.02/0.01] Common-mode differential mag (5)magphot.mag;arith.diffdoublemag[-0.8/1.61] Corrected differential magnitude (6)magphot.mag;arith.diffdoubleJ/AJ/163/168/fig2bc*MEarth light curve data for of LTT1445BCmag[-0.8/1.61] Corrected differential magnitude (6)magphot.mag;arith.diffdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJD[2458528/2459495] Barycentric Julian Date at mid-exposuredtime.epochdoubleindexedDmag[-0.8/1.61] Differential magnitudemagphot.mag;arith.diffdoublee_Dmag[0.002/0.2] Uncertainty in differential magnitudemagstat.error;phot.mag;arith.diffdoubleTexp[4.034] Exposure timestime.duration;obs.exposurefloatmag0[-3.98/0.25] Frame magnitude zero point offsetmagphot.mag;arith.zpfloatFWHM[-1/5.26] FWHM of stellar images (1)pixphys.angSizefloatEll[0.005/0.37] Ellipticity of stellar images (1)src.ellipticityfloatAirmass[1.02/2.06] Airmass at mid-exposureobs.airMassdoubleX[625/1427] X pixel coordinate of starpixpos.cartesian.xdoubleY[756/1288] Y pixel coordinate of starpixpos.cartesian.ydoubleAngle[-180/0.04] Angle relative to reference imagedeginstr.offsetfloatSky[1.77/4677] Local sky background levelinstr.skyLeveldoublePeak[691/21273] Peak counts in object, including skymeta.numberintSeg[1/2] Segment number (2)meta.idintVers[4] Instrument version numbermeta.number;instrintStatus[0/2] Realtime status flag (3)meta.code.errorintFlags[0] Flags (4)meta.code.errorintCM[-0.02/0.01] Common-mode differential mag (5)magphot.mag;arith.diffdouble