TOI-1130: A photodynamical analysis of a hot Jupiter in resonance with an inner low-mass planet
J. Korth, D. Gandolfi, J. Šubjak, Saburo Howard, Sareh Ataiee, Karen A. Collins, Samuel N. Quinn, Alexander J. Mustill, T. Guillot, N. Lodieu, A. M. S. Smith, M. Esposito, F. Rodler, A. Muresan, Lyu Abe, Simon Albrecht, A. Alqasim, Khalid Barkaoui, P. G. Beck, Christopher J. Burke, R. Paul Butler, Dennis M. Conti, Kevin I. Collins, Jeffrey D. Crane, F. Dai, H. J. Deeg, Phil Evans, S. Grziwa, A. P. Hatzes, Teruyuki Hirano, K. Horne, Chelsea X. Huang, Jon M. Jenkins, P. Kábath, John F. Kielkopf, Emil Knudstrup, David W. Latham, John H. Livingston, R. Luque, S. Mathur, F. Murgas, H. L. M. Osborne, Ε. Πάλλη, C. M. Persson, Joseph E. Rodriguez, Mark E. Rose, Pamela Rowden, Richard P. Schwarz, Sara Seager, L. M. Serrano, Lizhou Sha, Stephen A. Shectman, Avi Shporer, Gregor Srdoč, Chris Stockdale, Thiam-Guan Tan, Johanna Teske, Vincent Van Eylen, Andrew Vanderburg, R. Vanderspek, Sharon X. Wang, Joshua N. Winn
Abstract
The TOI-1130 is a known planetary system around a K-dwarf consisting of a gas giant planet, TOI-1130 c on an 8.4-day orbit that is accompanied by an inner Neptune-sized planet, TOI-1130 b, with an orbital period of 4.1 days. We collected precise radial velocity (RV) measurements of TOI-1130 with the HARPS and PFS spectrographs as part of our ongoing RV follow-up program. We performed a photodynamical modeling of the HARPS and PFS RVs, along with transit photometry from the Transiting Exoplanet Survey Satellite (TESS) and the TESS Follow-up Observing Program (TFOP). We determined the planet masses and radii of TOI-1130 b and TOI-1130 c to be M b = 19.28 ± 0.97 M ⊕ and R b = 3.56 ± 0.13 R ⊕ , and M c = 325.59 ± 5.59 M ⊕ and R c = 13.32 −1.41 +1.55 R ⊕ , respectively. We have spectroscopically confirmed the existence of TOI-1130 b, which had previously only been validated. We find that the two planets have orbits with small eccentricities in a 2:1 resonant configuration. This is the first known system with a hot Jupiter and an inner lower mass planet locked in a mean-motion resonance. TOI-1130 belongs to the small, yet growing population of hot Jupiters with an inner low-mass planet that poses a challenge to the pathway scenario for hot Jupiter formation. We also detected a linear RV trend that is possibly due to the presence of an outer massive companion.