Two sub-Neptunes around the M dwarf TOI-1470

González-Álvarez, E.; Zapatero Osorio, M. R.; Caballero, J. A.; Béjar, V. J. S.; Cifuentes, C.; Fukui, A.; Herrero, E.; Kawauchi, K.; Livingston, J. H.; López-González, M. J.; Morello, G.; Murgas, F.; Narita, N.; Pallé, E.; Passegger, V. M.; Rodríguez, E.; Rodríguez-López, C.; Sanz-Forcada, J.; Schweitzer, A.; Tabernero, H. M.; Quirrenbach, A.; Amado, P. J.; Charbonneau, D.; Ciardi, D. R.; Cikota, S.; Collins, K. A.; Conti, D. M.; Fausnaugh, M.; Hatzes, A. P.; Hedges, C.; Henning, Th.; Jenkins, J. M.; Latham, D. W.; Massey, B.; Moldovan, D.; Montes, D.; Panahi, A.; Reiners, A.; Ribas, I.; Ricker, G. R.; Seager, S.; Shporer, A.; Srdoc, G.; Tenenbaum, P.; Vanderspek, R.; Winn, J. N.; Fukuda, I.; Ikoma, M.; Isogai, K.; Kawai, Y.; Mori, M.; Tamura, M.; Watanabe, N.
Bibliographical reference

Astronomy and Astrophysics

Advertised on:
7
2023
Number of authors
53
IAC number of authors
7
Citations
3
Refereed citations
3
Description

Aims: A transiting planet candidate with a sub-Neptune radius orbiting the nearby (d = 51.9 ± 0.07 pc) M1.5 V star TOI-1470 with a period of ~2.5 d was announced by the NASA Transiting Exoplanet Survey Satellite (TESS), which observed the field of TOI-1470 in four different sectors. We aim to validate its planetary nature using precise radial velocities (RVs) taken with the CARMENES spectrograph.
Methods: We obtained 44 RV measurements with CARMENES spanning eight months between 3 June 2020 and 17 January 2021. For a better characterization of the parent star activity, we also collected contemporaneous optical photometric observations at the Joan Oró and Sierra Nevada Observatories, and we retrieved archival photometry from the literature. We used ground-based photometric observations from MuSCAT and also from MuSCAT2 and MuSCAT3 to confirm the planetary transit signals. We performed a combined photometric and spectroscopic analysis by including Gaussian processes and Keplerian orbits to simultaneously account for the stellar activity and planetary signals.
Results: We estimate that TOI-1470 has a rotation period of 29 ± 3d based on photometric and spectroscopic data. The combined analysis confirms the discovery of the announced transiting planet, TOI-1470 b, with an orbital period of 2.527093 ± 0.000003 d, a mass of 7.32-1.24+1.21M⊕, and a radius of 2.18-0.04+0.04R⊕. We also discover a second transiting planet that was not announced previously by TESS, TOI-1470 c, with an orbital period of 18.08816 ± 0.00006 d, a mass of 7.24-2.77+2.87M⊕, and a radius of 2.47-0.02+0.02R⊕ . The two planets are placed on the same side of the radius valley of M dwarfs and lie between TOI-1470 and the inner border of its habitable zone.
Related projects
Projects' name image
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
Enric
Pallé Bago
Discovery of a system of super-Earths orbiting the star HD 176986 with about 5.7 and 9.2 Earth masses.
Very Low Mass Stars, Brown Dwarfs and Planets
Our goal is to study the processes that lead to the formation of low mass stars, brown dwarfs and planets and to characterize the physical properties of these objects in various evolutionary stages. Low mass stars and brown dwarfs are likely the most numerous type of objects in our Galaxy but due to their low intrinsic luminosity they are not so
Rafael
Rebolo López