A sub-Neptune and a non-transiting Neptune-mass companion unveiled by ESPRESSO around the bright late-F dwarf HD 5278 (TOI-130)

• Tipo: Artigo em Revista Científica Internacional
• Data: 2021

Autores

Sozzetti, A (Autor) Outra; Damasso, M (Autor) Outra; Bonomo, AS (Autor) Outra; Alibert, Y (Autor) Outra; Sousa, SG (Autor) FCUP; Adibekyan, V (Autor) Outra; Osorio, MRZ (Autor) Outra; Hernandez, JIG (Autor) Outra; Barros, SCC (Autor) FCUP; Lillo Box, J (Autor) Outra; Stassun, KG (Autor) Outra; Winn, J (Autor) Outra; Cristiani, S (Autor) Outra; Pepe, F (Autor) Outra; Rebolo, R (Autor) Outra; N.C. Santos (Autor) FCUP; Allart, R (Autor) Outra; Barclay, T (Autor) Outra; Bouchy, F (Autor) Outra; Cabral, A (Autor) Outra; Ciardi, D (Autor) Outra; Di Marcantonio, P (Autor) Outra; D'Odorico, V (Autor) Outra; Ehrenreich, D (Autor) Outra; Fasnaugh, M (Autor) Outra; Figueira, P (Autor) Outra; Haldemann, J (Autor) Outra; Jenkins, JM (Autor) Outra; Latham, DW (Autor) Outra; Lavie, B (Autor) Outra; Lo Curto, G (Autor) Outra; Lovis, C (Autor) Outra; Martins, CJAP (Autor) FCUP; Megevand, D (Autor) Outra; Mehner, A (Autor) Outra; Micela, G (Autor) Outra; Molaro, P (Autor) Outra; Nunes, NJ (Autor) Outra; Oshagh, M (Autor) Outra; Otegi, J (Autor) Outra; Palle, E (Autor) Outra; Poretti, E (Autor) Outra; Ricker, G (Autor) Outra; Rodriguez, D (Autor) Outra; Seager, S (Autor) Outra; Mascareno, AS (Autor) Outra; Twicken, JD (Autor) Outra; Udry, S (Autor) Outra

Revista

Título: Astronomy and Astrophysics

Vol. 648

Página Final: A75

ISSN: 0004-6361

Editora: EDP Sciences

Indexação

ISI Web of Knowledge - 20 Citações

Scopus - 19 Citações

Outras Informações

ID Authenticus: P-00T-TNA

DOI: 10.1051/0004-6361/202040034

Abstract (EN): Context. Transiting sub-Neptune-type planets, with radii approximately between 2 and 4 R-circle plus, are of particular interest as their study allows us to gain insight into the formation and evolution of a class of planets that are not found in our Solar System.Aims. We exploit the extreme radial velocity (RV) precision of the ultra-stable echelle spectrograph ESPRESSO on the VLT to unveil the physical properties of the transiting sub-Neptune TOI-130 b, uncovered by the TESS mission orbiting the nearby, bright, late F-type star HD 5278 (TOI-130) with a period of P-b = 14.3 days. Methods. We used 43 ESPRESSO high-resolution spectra and broad-band photometry information to derive accurate stellar atmospheric and physical parameters of HD 5278. We exploited the TESS light curve and spectroscopic diagnostics to gauge the impact of stellar activity on the ESPRESSO RVs. We performed separate as well as joint analyses of the TESS photometry and the ESPRESSO RVs using fully Bayesian frameworks to determine the system parameters. Results. Based on the ESPRESSO spectra, the updated stellar parameters of HD 5278 are T-eff = 6203 +/- 64 K, log g = 4.50 +/- 0.11 dex, [Fe/H] = -0.12 +/- 0.04 dex, M-star=1.126(-0.035)(+0.036) M-circle dot, and R-star=1.194(-0.016)(+0.017) R star=1.194(-0.016)(+0.017) R-circle dot. We determine HD 5278 b's mass and radius to be M-b=7.8(-1.4)(+1.5) M-circle plus and R-b = 2.45 +/- 0.05R(circle plus). The derived mean density, rho(b)=2.9(-0.5)(+0.6) g cm(-3), is consistent with the bulk composition of a sub-Neptune with a substantial (similar to 30%) water mass fraction and with a gas envelope comprising similar to 17% of the measured radius. Given the host brightness and irradiation levels, HD 5278 b is one of the best targetsorbiting G-F primaries for follow-up atmospheric characterization measurements with HST and JWST. We discover a second, non-transiting companion in the system, with a period of P-c=40.87(-0.17)(+0.18) days and a minimum mass of M-c sini(c)=18.4(-1.9)(+1.8) M-circle plus. We study emerging trends in parameters space (e.g., mass, radius, stellar insolation, and mean density) of the growing population of transiting sub-Neptunes, and provide statistical evidence for a low occurrence of close-in, 10 - 15M(circle plus) companions around G-F primaries with T-eff greater than or similar to 5500 K.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 25