A long-period transiting substellar companion in the super-Jupiters to brown dwarfs mass regime and a prototypical warm-Jupiter detected by TESS
Trifonov, Trifon; Henning, Thomas; Triaud, Amaury H. M. J.; Uzundag, Murat; Jordán, Andrés; Espinoza, Néstor; Brahm, Rafael; Hobson, Melissa J.; Eberhardt, Jan; Schlecker, Martin; Jones, Matías I.; Moyano, Maximiliano; Ziegler, Carl; Lissauer, Jack J.; Ricker, George R.; Seager, Sara; Winn, Joshua N.; Jenkins, Jon M.; Caldwell, Douglas A.; Boyle, Gavin; Dransfield, Georgina; Shporer, Avi; Dragomir, Diana; Lendl, Monika; Lund, Michael B.; Mann, Andrew W.; Ducrot, Elsa; Queloz, Didier; Torres-Miranda, Pascal; Sarkis, Paula; Hesse, Katharine; Figueira, Pedro; Burke, Christopher J.; Gupta, Arvind F.; Gillon, Michael; Ulmer-Moll, Solène; Psaridi, Angelica; Timmermans, Mathilde; Martin, David V.; Standing, Matthew R.; Hooton, Matthew J.; Rojas, Felipe; Sebastian, Daniel; Suc, Vincent; Tala Pinto, Marcelo; Baycroft, Thomas; Mounzer, Dany; Reinarz, Yared; Al Moulla, Khaled; Zuñiga-Fernández, Sebastián; Carson, Joe
Chile, Germany, United Kingdom, United States, Bulgaria, Switzerland, Belgium, Spain, France
Abstract
We report on the confirmation and follow-up characterization of two long-period transiting substellar companions on low-eccentricity orbits around TIC 4672985 and TOI-2529, whose transit events were detected by the TESS space mission. Ground-based photometric and spectroscopic follow-up from different facilities, confirmed the substellar nature of TIC 4672985 b, a massive gas giant in the transition between the super-Jupiters and brown dwarfs mass regime. From the joint analysis we derived the following orbital parameters: P = 69.0480−0.0005+0.0004 d, Mp = 12.74−1.01+1.01 Mj, Rp = 1.026−0.067+0.065 Rj and e = 0.018−0.004+0.004. In addition, the RV time series revealed a significant trend at the ~350 m s−1 yr−1 level, which is indicative of the presence of a massive outer companion in the system. TIC 4672985 b is a unique example of a transiting substellar companion with a mass above the deuterium-burning limit, located beyond 0.1 AU and in a nearly circular orbit. These planetary properties are difficult to reproduce from canonical planet formation and evolution models. For TOI-2529 b, we obtained the following orbital parameters: P = 64.5949−0.0003+0.0003 d, Mp = 2.340−0.195+0.197 Mj, Rp = 1.030−0.050+0.050 Rj and e = 0.021−0.015+0.024, making this object a new example of a growing population of transiting warm giant planets.
Based on observations collected at La Silla - Paranal Observatory under programs IDs 105.20GX.001, 106.212H.001, 106.21ER.001 and 108.22A8.001 and through the Chilean Telescope Time under programs IDs CN2020B-21, CN2021A-14, CN2021B-23, CN2022A-33 and CN2022B-33.