9 papers
Nautilus: Fast Time-Resolved Spectroscopy of GKM Stellar Flares and Their Implications for Planetary Habitability
Chia-Lung Lin, Adina D. Feinstein, Jeff Valenti +10
Low-mass GKM dwarfs are prime targets for finding habitable-zone Earth-sized planets, but their frequent flares, especially on M~dwarfs, can strongly affect planetary atmospheres t…
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…
A single power law for the TRAPPIST-1 flare distribution across four orders of magnitude in energy
Valeriy Vasilyev, Alexander I. Shapiro, Nadiia Kostogryz +10
TRAPPIST-1 is an ultra-cool dwarf that flares frequently. These flares shape the surrounding planets' high-energy irradiation environments, with consequences for atmospheric chemis…
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…