CFHT UM2019 - Presentation Details

Abstract Details

Title: Investigating the magnetism and activity of epsilon Eridani from nearly simultaneous observations with SPIRou, NARVAL, and TESS

Presenter: Pascal Petit


We report on observations of the active K2 dwarf epsilon Eridani, obtained in 2018 in near simultaneity with SPIRou, NARVAL, and TESS. Near infrared spectropolarimetry with SPIRou was obtained over 4 nights in late September, while the visible NARVAL time series extends from 18 Sept to 07 Nov. The photometric monitoring with TESS was secured between 19 Oct and 15 Nov. We first recover the fundamental parameters of the target from both visible and nIR spectral models. The large-scale magnetic field geometry is then investigated from SPIRou and NARVAL polarimetric data, as well as its short term evolution under the effect of surface differential rotation. From unpolarized spectra, we also estimate the total magnetic flux through Zeeman broadening (using magnetically sensitive nIR lines) and the chromospheric emission (using nUV CaII line cores). We finally model the TESS light curve with pseudo-periodic Gaussian Process Regression. After detailing the outcome of this very diverse view of the photospheric and chromospheric activity of epsilon Eridani, we discuss the phase dependence of all magnetic measurements and activity proxies.