13 papers
Towards understanding stellar variability at the sub m/s level: granulation-induced variability across the optical spectrum
Cis Lagae, Ginger Frame, Heather M. Cegla +5
Detecting the radial velocity signal of Earth-mass exoplanets requires the characterisation and removal of granulation-induced radial velocity variability from spectroscopic observ…
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-…
Effect of surface magnetic fields on limb darkening in main-sequence stars
N. Kostogryz, A. I. Shapiro, V. Witzke +5
Context.Stellar limb darkening encodes the thermal and radiative structure of stellar photospheres and is a key ingredient in modeling transit light curves and transmission spectra…
Decoding the Radial Velocity Signatures of Solar Faculae with 3D MHD Simulations
Florian Kröll, Sowmya Krishnamurthy, Alexander Shapiro +8
We model the solar radial velocity (RV) signal induced by faculae, the dominant contributor to RV variability in Sun-like stars. We use a representative case of a facular patch tra…
Sensitivity of spectral lines to granulation: from the Sun to K-type stars
V. Vasilyev, K. Sowmya, A. I. Shapiro +7
Stellar granulation produces radial-velocity (RV) jitter at the 1 m/s level in Sun-like stars, limiting Earth-analog detection. A route beyond this limit is to weight spectral line…
Sensitivity of spectral lines to granulation: The Sun
K. Sowmya, A. I. Shapiro, V. Vasilyev +3
The intrinsic variability of stars, due to acoustic oscillations, surface granulation, and magnetic activity, introduces radial velocity (RV) jitter in spectral lines, obscuring tr…