5 papers
The Fe I 4377 Ã Line as a Solar Faculae Indicator: Insights from Spectral Ratio Analysis
Katlyn L. Hobbs, Christopher A. Watson, Jean C. Costes +21
Faculae are a dominant source of stellar activity noise in radial velocity measurements, yet their low contrast and broad surface distribution make them difficult to track in disc-…
A Decade of Solar High-Fidelity Spectroscopy and Precise Radial Velocities from HARPS-N
X. Dumusque, K. Al Moulla, M. Cretignier +53
We recently released 10 years of HARPS-N solar telescope and the goal of this manuscript is to present the different optimisations made to the data reduction, to describe data cura…
Granulation on a quiet K dwarf: HD 166620 I. Spectral signatures as a function of line-formation temperature
Ancy Anna John, Khaled Al Moulla, Niamh K. O'Sullivan +14
As Radial velocity (RV) spectrographs reach unprecedented precision and stability below 1 m/s, the challenge of granulation in the context of exoplanet detection has intensified. D…
Using Doppler Imaging to model stellar activity and search for planets around Sun-like stars
Baptiste Klein, Suzanne Aigrain, Michael Cretignier +9
Doppler Imaging (DI) is a well-established technique to map a physical field at a stellar surface from a time series of high-resolution spectra. In this proof-of-concept study, we…
Measuring the Suns radial velocity variability due to supergranulation over a magnetic cycle
Niamh K. O'Sullivan, Suzanne Aigrain, Michael Cretignier +9
In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity planet searches. We used eight years of Sun-as-a-s…