Monthly Notices of the Royal Astronomical Society • Vol 528 • No 4
Modelling stellar variability in archival HARPS data: I - Rotation and activity properties with multidimensional Gaussian processes
January 2024 • Haochuan Yu, S. Aigrain, Baptiste Klein, Oscar Barragán, Annelies Mortier, Niamh K. O'Sullivan, M. Cretignier
ABSTRACT Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-metre per second accuracy, the detection of low-mass planets is still very challenging. The rotational modulation and evolution of spots and/or faculae can induce variations in the RVs at the level of a few m s–1 in Sun-like stars. To overcome this, a multidimensional Gaussian Process framework has been developed to model the stellar activity signal using spectroscopic activity indicators together with the RVs.…