TOI-954 b and K2-329 b: Short-period Saturn-mass Planets that Test whether Irradiation Leads to Inflation

Sha, LizhouLizhouShaHuang, Chelsea X.Chelsea X.HuangShporer, AviAviShporerRodriguez, Joseph E.Joseph E.RodriguezVanderburg, AndrewAndrewVanderburgBrahm, RafaelRafaelBrahmHagelberg, JanisJanisHagelbergMatthews, Elisabeth C.Elisabeth C.MatthewsZiegler, CarlCarlZieglerLivingston, John H.John H.LivingstonStassun, Keivan G.Keivan G.StassunWright, Duncan J.Duncan J.WrightCrane, Jeffrey D.Jeffrey D.CraneEspinoza, NestorNestorEspinozaBouchy, FrancoisFrancoisBouchyBakos, Gaspar A.Gaspar A.BakosCollins, Karen A.Karen A.CollinsZhou, GeorgeGeorgeZhouBieryla, AllysonAllysonBierylaHartman, Joel D.Joel D.HartmanWittenmyer, Robert A.Robert A.WittenmyerNielsen, Louise D.Louise D.NielsenPlavchan, PeterPeterPlavchanBayliss, DanielDanielBaylissSarkis, PaulaPaulaSarkisTan, Thiam-GuanThiam-GuanTanCloutier, RyanRyanCloutierMancini, LuigiLuigiManciniJordan, AndresAndresJordanWang, SharonSharonWangHenning, ThomasThomasHenningNarita, NorioNorioNaritaPenev, KaloyanKaloyanPenevTeske, Johanna K.Johanna K.TeskeKane, Stephen R.Stephen R.KaneMann, Andrew W.Andrew W.MannAddison, Brett C.Brett C.AddisonTamura, MotohideMotohideTamuraHorner, JonathanJonathanHornerBarbieri, MauroMauroBarbieriBurt, Jennifer A.Jennifer A.BurtDiaz, Matias R.Matias R.DiazCrossfield, Ian J. M.Ian J. M.CrossfieldDragomir, DianaDianaDragomirDrass, HolgerHolgerDrassFeinstein, Adina D.Adina D.FeinsteinZhang, HuiHuiZhangHart, RhodesRhodesHartKielkopf, John F.John F.KielkopfJensen, Eric L. N.Eric L. N.JensenMontet, Benjamin T.Benjamin T.MontetOttoni, GaelGaelOttoniSchwarz, Richard P.Richard P.SchwarzRojas, FelipeFelipeRojasNespral, DavidDavidNespralTorres, PascalPascalTorresMengel, Matthew W.Matthew W.MengelUdry, StephaneStephaneUdryZapata, AbnerAbnerZapataSnoddy, ErinErinSnoddyOkumura, JackJackOkumuraRicker, George R.George R.RickerVanderspek, Roland K.Roland K.VanderspekLatham, David W.David W.LathamWinn, Joshua N.Joshua N.WinnSeager, SaraSaraSeagerJenkins, Jon M.Jon M.JenkinsColon, Knicole D.Knicole D.ColonHenze, Christopher E.Christopher E.HenzeKrishnamurthy, AkshataAkshataKrishnamurthyTing, Eric B.Eric B.TingVezie, MichaelMichaelVezieVillanueva, StevenStevenVillanueva2025-12-302025-12-3020211538-3881https://hdl.handle.net/20.500.12740/24167We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534, V = 10.343, T = 9.78) observed in TESS sectors 4 and 5 and one transiting the G dwarf K2-329 (EPIC 246193072, V = 12.70, K = 10.67) observed in K2 campaigns 12 and 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of 0.852(-0.062)(+0.053) R-J and a mass of 0.174(-0.017)(+0.018) M-J and is in a 3.68 day orbit, while K2-329 b has a radius of 0.774(-0.024)(+0.026) R-J and a mass if 0.260(-0.022)(+0.020) M-J and is in a 12.46 day orbit. As TOI-954 b is 30 times more irradiated than K2-329 b but more or less the same size, these two planets provide an opportunity to test whether irradiation leads to inflation of Saturn-mass planets and contribute to future comparative studies that explore Saturn-mass planets at contrasting points in their lifetimes.Acceso AbiertoSTARS1STALGORITHMRADIUSHOSTNAOSRICHTOI-954 b and K2-329 b: Short-period Saturn-mass Planets that Test whether Irradiation Leads to Inflationhttp://dx.doi.org/10.3847/1538-3881/abd187