We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine T-eff,T-* = 4734 +/- 67 K, R-* = 0.726 +/- 0.007 R-circle dot, and M-* = 0.748 +/- 0.032 M-circle dot. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of P-b = 6.44387 +/- 0.00003 d, a radius of R-b = 2.59 +/- 0.04 R-circle plus, and a mass of M-b = 13.5(-1.8)(+1.7) M-circle plus, whilst TOI-1064 c has an orbital period of P-c = 12.22657(-0.00004)(+0.00005) d, a radius of R-c = 2.65 +/- 0.04 R-circle plus, and a 3 sigma upper mass limit of 8.5 M-circle plus. From the high-precision photometry we obtain radius uncertainties of similar to 1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass-radius space, and it allow us to identify a trend in bulk density-stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets.

A pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 characterized with CHEOPS

Goffo, E;Gandolfi, D;Serrano, LM;
2022-01-01

Abstract

We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine T-eff,T-* = 4734 +/- 67 K, R-* = 0.726 +/- 0.007 R-circle dot, and M-* = 0.748 +/- 0.032 M-circle dot. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of P-b = 6.44387 +/- 0.00003 d, a radius of R-b = 2.59 +/- 0.04 R-circle plus, and a mass of M-b = 13.5(-1.8)(+1.7) M-circle plus, whilst TOI-1064 c has an orbital period of P-c = 12.22657(-0.00004)(+0.00005) d, a radius of R-c = 2.65 +/- 0.04 R-circle plus, and a 3 sigma upper mass limit of 8.5 M-circle plus. From the high-precision photometry we obtain radius uncertainties of similar to 1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass-radius space, and it allow us to identify a trend in bulk density-stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets.
2022
Inglese
Esperti anonimi
511
1
1043
1071
29
https://academic.oup.com/mnras/article/511/1/1043/6506474
techniques: photometric; techniques: radial velocities; planets and satellites: composition; planets and satellites: detection; planets and satellites: interiors; stars: individual: TOI-1064 (TIC 79748331, Gaia EDR3 6683371847364921088)
   GANDOLFI D. - Fondaz.CRT - II tornata 2018 - Rif. 2018.2323 - "Gaseous or rocky? Unveiling the nature of small worlds"
   FONDAZIONE CRT
   Rif. 2018.2323
4 – prodotto già presente in altro archivio Open Access (arXiv, REPEC…)
262
135
Wilson, TG; Goffo, E; Alibert, Y; Gandolfi, D; Bonfanti, A; Persson, CM; Cameron, AC; Fridlund, M; Fossati, L; Korth, J; Benz, W; Deline, A; Florén, H...espandi
info:eu-repo/semantics/article
open
03-CONTRIBUTO IN RIVISTA::03A-Articolo su Rivista
File in questo prodotto:
File Dimensione Formato  
Wilson_2022.pdf

Accesso aperto

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 6.78 MB
Formato Adobe PDF
6.78 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1948543
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 39
  • ???jsp.display-item.citation.isi??? 30
social impact