Authors: Varun Chaturmutha (Georgia State University), Stuart Jefferies (Georgia State University), Bernard Fleck (ESA Science Operations Department), Daniele Calchetti (Max Planck Institute for Solar System Research)
We use Doppler velocity observations of the Sun, as if it were a distant star, to probe the properties of the Sun’s atmosphere via travel-time analysis of seismic (acoustic-gravity) waves. The data set comprises 11 years of disk-integrated line-of-sight velocity observations from SDO/HMI and SOHO/GOLF that probe different heights in the atmosphere. Our results highlight the potential for the future seismic probing of stellar atmospheres, offering insights into properties like line formation heights, sound speed, radiative cooling times, and stellar cycles. Additionally, this study reveals an intriguing prospect of observing atmospheric gravity waves (AGW) near the limb, as we see potential AGW signatures in disk-integrated (low degree mode) observations.