papers

Publications (5)

astro-ph.SR2025

Solar Flux Atlases: The new HARPS-N Quiet Sun Benchmark and Ca II H & K Lines Continuum Normalisation

F. Hanassi-Savari, A. G. M. Pietrow, M. K. Druett +2

Context. Solar flux atlases observe the spatially integrated light from the Sun, treating it as a star. They are fundamental tools for gaining insight into the composition of the S…

astro-ph.IM2026

Observing the integrated and spatially resolved Sun with ultra-high spectral resolution

S. Schäfer, K. Royen, A. Huster Zapke +2

The Institute for Astrophysics Göttingen operates a solar observatory that combines a 50\,cm siderostat with (1) a vacuum vertical telescope, (2) a very high resolution Fourier Tr…

astro-ph.SR2023

Convective characteristics of Fe I lines across the solar disc

M. Ellwarth, B. Ehmann, S. Schäfer +1

Solar convection is visible as a net blueshift of absorption lines, which becomes apparent when observing quiet Sun granulation. This blueshift exhibits variations from the disc ce…

astro-ph.SR2023

The IAG spectral atlas of the spatially resolved Sun: Centre-to-limb observations

M. Ellwarth, S. Schäfer, A. Reiners +1

Solar surface magneto-convection appears as granulation pattern that impacts spectral lines in terms of both shape and wavelength. Such induced effects also tend to vary over the o…

astro-ph.SR2021

Newly formed downflow lanes in exploding granules in the solar photosphere

M. Ellwarth, C. E. Fischer, N. Vitas +2

Exploding granules have drawn renewed interest because of their interaction with the magnetic field. Especially the newly forming downflow lanes developing in their centre seem to…