Circumstellar environment of 55 Cancri. The super-Earth 55 Cnc e as a primary target for star-planet interactions - Archive ouverte HAL Access content directly
Journal Articles Astronomy and Astrophysics - A&A Year : 2020

Circumstellar environment of 55 Cancri. The super-Earth 55 Cnc e as a primary target for star-planet interactions

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1
C. P. Folsom
D. Ó Fionnagáin
  • Function : Author
L. Fossati
  • Function : Author
A. A. Vidotto
  • Function : Author
D. Dragomir

Abstract

Context. 55 Cancri hosts five known exoplanets, most notably the hot super-Earth 55 Cnc e, which is one of the hottest known transiting super-Earths. Aims: Because of the short orbital separation and host star brightness, 55 Cnc e provides one of the best opportunities for studying star-planet interactions (SPIs). We aim to understand possible SPIs in this system, which requires a detailed understanding of the stellar magnetic field and wind impinging on the planet. Methods: Using spectropolarimetric observations and Zeeman Doppler Imaging, we derived a map of the large-scale stellar magnetic field. We then simulated the stellar wind starting from the magnetic field map, using a 3D magneto-hydrodynamic model. Results: The map of the large-scale stellar magnetic field we derive has an average strength of 3.4 G. The field has a mostly dipolar geometry; the dipole is tilted by 90° with respect to the rotation axis and the dipolar strength is 5.8 G at the magnetic pole. The wind simulations based on this magnetic geometry lead us to conclude that 55 Cnc e orbits inside the Alfvén surface of the stellar wind, implying that effects from the planet on the wind can propagate back to the stellar surface and result in SPI. Based on observations obtained at the Telescope Bernard Lyot (USR5026) operated by the Observatoire Midi-Pyrénées, Université de Toulouse (Paul Sabatier), Centre National de la Recherche Scientifique of France.

Dates and versions

hal-03024169 , version 1 (25-11-2020)

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C. P. Folsom, D. Ó Fionnagáin, L. Fossati, A. A. Vidotto, C. Moutou, et al.. Circumstellar environment of 55 Cancri. The super-Earth 55 Cnc e as a primary target for star-planet interactions. Astronomy and Astrophysics - A&A, 2020, ⟨10.1051/0004-6361/201937186⟩. ⟨hal-03024169⟩
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