Speaker: Heather Cegla (University of Warwick | Coventry, UK)

Title: Exploring the impact of stellar variability in high resolution spectroscopy through observations and simulations

Abstract: High-precision, high-resolution spectroscopy is a powerful tool for confirming and characterising exoplanets, but variability on stellar surfaces can contaminate these measurements. In this talk, I will provide an overview of the work my group is performing in this area. I will show our most recent efforts studying granulation on Sun-like stars using 3D stellar atmosphere simulations across a range of stellar lines in the optical. We also use spectroscopic observations of transiting planets to spatially resolve stellar surfaces. I will share our analysis of the WASP-85 A system, where we use the transiting planet to spatially resolve the surface and isolate the properties of an occulted starspot. Finally, I will discuss our use of high-resolution cross-correlation spectroscopy to characterise exoplanet atmospheres and examine how stellar surface variability can bias these measurements through forward modelling.

Note: Host: Katja Poppenhäger

• Date:
  April 23, 2026, 2:30 p.m. – 3:30 p.m.
  
  
• Location:

  AIP; Kirch building, Conference room

  
  
• Contact:
  Julián Alvarado-Gómez
  julian.alvarado-gomez@aip.de