activity
19982026
most citedPlanets and Stellar Activity: Hide and Seek in the CoRoT-7 system

522 citations · 3.1k across the 46 of their papers we have counts for

collaborators

47 papers

astro-ph.EP2026

K-dwarf starspot hunters: how to directly characterize spot and faculae properties with UV-IR panchromatic transit spectra

Joanna K. Barstow, Caitlyn Cullen, Yvonne Unruh +7

Transmission spectroscopy of exoplanets provides an important window into their atmospheric composition, structure and dynamics, especially in the JWST era. As the quality of the o…

astro-ph.SR2026

The Fe I 4377 Å 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-…

astro-ph.SR2024★ 1 cited

First Calculations of Starspot Spectra based on 3D Radiative Magnetohydrodynamics Simulations

H. N. Smitha, Alexander I. Shapiro, Veronika Witzke +6

Accurate calculations of starspot spectra are essential for multiple applications in astronomy. The current standard is to represent starspot spectra by spectra of stars that are c…

astro-ph.EP2024

Reliable Transmission Spectrum Extraction with a Three-Parameter Limb Darkening Law

Rosa E. Keers, Alexander I. Shapiro, Nadiia M. Kostogryz +7

Stellar limb darkening must be properly accounted for to accurately determine the radii of exoplanets at various wavelengths. The standard approach to address limb darkening involv…

astro-ph.SR2023★ 18 cited

Testing MURaM and MPS-ATLAS against the quiet solar spectrum

Veronika Witzke, Alexander I. Shapiro, Nadiia M. Kostogryz +8

Three-dimensional (3D) radiative magnetohydrodynamics (MHD) simulations are the only way to model stellar atmospheres without any ad hoc parameterisations. Several 3D radiative MHD…

astro-ph.SR2023★ 27 cited

Spectral variability of photospheric radiation due to faculae II: Facular contrasts for cool main-sequence stars

Charlotte M. Norris, Yvonne C. Unruh, Veronika Witzke +5

Magnetic features on the surface of stars, such as spots and faculae, cause stellar spectral variability on time-scales of days and longer. For stars other than the Sun, the spectr…