TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter
| Autor: | Lillo-Box, J., Gandolfi, D., Armstrong, D. J., Collins, K. A., Nielsen, L. D., Luque, R., Korth, J., Sousa, S. G., Quinn, S. N., Acuña, L., Howell, S. B., Morello, G., Hellier, C., Giacalone, S., Hoyer, S., Stassun, K., Palle, E., Aguichine, A., Mousis, O., Adibekyan, V., Silva, T. Azevedo, Barrado, D., Deleuil, M., Eastman, J. D., Hawthorn, F., Irwin, J. M., Jenkins, J. M., Latham, D. W., Muresan, A., Persson, C. M., Santerne, A., Santos, N. C., Savel, A. B., Osborn, H. P., Teske, J., Wheatley, P. J., Winn, J. N., Barros, S. C. C., Butler, R. P., Caldwell, D. A., Charbonneau, D., Cloutier, R., Crane, J. D., Demangeon, O. D. S., Díaz, R. F., Dumusque, X., Esposito, M., Falk, B., Gill, H., Hojjatpanah, S., Kreidberg, L., Mireles, I., Osborn, A., Ricker, G. R., Rodriguez, J. E., Schwarz, R. P., Seager, S., Bell, J. Serrano, Shectman, S. A., Shporer, A., Vezie, M., Wang, S. X., Zhou, G. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | A&A 669, A109 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361/202243879 |
| Popis: | The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their picture. In this paper we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star. We use a set of precise radial velocity observations from HARPS, PFS and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system. We find that TOI-969 b is a transiting close-in ($P_b\sim 1.82$ days) mini-Neptune planet ($m_b=9.1^{+1.1}_{-1.0}$ M$_{\oplus}$, $R_b=2.765^{+0.088}_{-0.097}$ R$_{\oplus}$), thus placing it on the {lower boundary} of the hot-Neptune desert ($T_{\rm eq,b}=941\pm31$ K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of $P_c=1700^{+290}_{-280}$ days and a minimum mass of $m_{c}\sin{i_c}=11.3^{+1.1}_{-0.9}$ M$_{\rm Jup}$, and with a highly-eccentric orbit of $e_c=0.628^{+0.043}_{-0.036}$. The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93, and it orbits a moderately bright ($G=11.3$ mag) star, thus becoming an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems. Comment: Accepted for publication in A&A. 25 pages, 15 figures, 12 tables |
| Databáze: | arXiv |
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