J/AJ/168/196ivo://CDS.VizieR/J/AJ/168/196doi:10.26093/cds/vizier.51680196CDSLubin J.Petigura E.A.Van Zandt J.Beard C.Dai F.Halverson S.,Holcomb R.Howard A.W.Isaacson H.Luhn J.Robertson P.,Rubenzahl R.A.Stefansson G.Winn J.N.Brodheim M.Deich W.,Hill G.M.Gibson S.R.Holden B.Householder A.Laher R.R.Lanclos K.,Payne J.Roy A.Smith R.Shaum A.P.Schwab C.Walawender J.2025-08-11T20:12:57Z2025-06-17T14:40:48ZCDS support team

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

cds-question@unistra.frexoplanetsradial-velocityvisible-astronomyspectroscopyWe report the sky-projected spin-orbit angle {lambda} for HD 191939 b, the innermost planet in a six-planet system, using Keck/KPF to detect the Rossiter-McLaughlin (RM) effect. Planet b is a sub-Neptune with radius 3.4+/-0.8R_{Earth}_ and mass 10.0+/-0.7M_{Earth}_ with an RM amplitude <1m/s. We find the planet is consistent with a well-aligned orbit, measuring {lambda}=3.7+/-5.0{deg}. Additionally, we place new constraints on the mass and period of the distant super-Jupiter, planet f, finding it to be 2.88+/-0.26M_J_ on a 2898+/-152days orbit. With these new orbital parameters, we perform a dynamical analysis of the system and constrain the mutual inclination of the nontransiting planet e to be smaller than 12{deg} relative to the plane shared by the inner three transiting planets. Additionally, the further planet f is inclined off this shared plane, the greater the amplitude of precession for the entire inner system, making it increasingly unlikely to measure an aligned orbit for planet b. Through this analysis, we show that this system's wide variety of planets are all well-aligned with the star and nearly coplanar, suggesting that the system formed dynamically cold and flat out of a well-aligned protoplanetary disk, similar to our own solar system.2024AJ....168..196Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/196CatalogResearchIsServedByTAP VizieR generic servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)J/AJ/154/109 : CKS. III. Planet radii (Fulton+, 2017)J/AJ/155/48 : (CKS). V. Masses and radii (Weiss+, 2018)J/AJ/155/177 : Obliquities: planetary & eclipsing binary syst. (Dai+, 2018)J/AJ/160/192 : Photometry and RVs of K2-25b with HPF (Stefansson+, 2020)J/AJ/161/68 : Obliquities: 150 hot Kepler hosting stars (Louden+, 2021)J/AJ/163/247 : HIRES, PEPSI & TRES RVs of V1298 Tau (Johnson+, 2022)J/AJ/163/101 : TESS-Keck survey. IX. RVs of HD1919139 (Lubin+, 2022)J/ApJ/931/L15 : 2 transits obs. of GJ 3470b with NEID (Stefansson+, 2022)J/ApJ/944/L41 : In-transit sp. & phot. obs. of TOI-2076b (Frazier+, 2023)J/ApJS/272/32 : TKS. XX. Exoplanet masses & orbit param. (Polanski+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/168/196https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/168/196http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/168/196https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/168/196https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/168/196http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/168/196GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/168/196/table3ObservationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Datedtime.epoch;obsdoubleRVel[-9247/57] Radial velocity from Inst (RV)m/sspect.dopplerVelocdoublee_RVel[0.5/13.1] Uncertainty in RVel (e_RV_)m/sstat.error;spect.dopplerVelocfloatInstInstrument used (Instrument) (1)meta.id;instrcharRefReference (Source) (2)meta.ref;spect.dopplerVelocchar