29 citations · 69 across the 10 of their papers we have counts for
10 papers
Center-to-limb variations of solar active regions: Observations of spots, faculae, and network in the 6173 Å continuum
A. G. M. Pietrow, S. Sumra, D. J. M. Petit dit de la Roche +3
Accurate modeling of stellar active regions (ARs) remains a major bottleneck for radial-velocity and transmission-spectroscopy studies aimed at finding Earth-like planets. While mu…
The calm before the storm: High spatial resolution mosaic of active region NOAA 14274 at the onset of an X1.2 flare
Carsten Denker, Robert Kamlah, Meetu Verma +1
Active region NOAA 14274 produced some of the strongest flares of Solar Cycle 25, including the X1.2 and X5.1 flares on 10 and 11 November 2025, respectively. We present the first…
High-spectral Resolution, Multi-wavelength Center-to-limb Observations of the Sun
Meetu Verma, Carsten Denker, Alexander G. M. Pietrow +2
The center-to-limb variations (CLVs) of photospheric and chromospheric spectral lines were obtained in 2025 July and August using drift scans from the echelle spectrograph of the 0…
Automatic detection of Ellerman bombs in the H line
A. Faryad, A. G. M. Pietrow, M. Verma +1
Ellerman bombs (EBs) are small and short-lived magnetic reconnection events in the lower solar atmosphere, most commonly reported in the line wings of the H line. These events a…
Differential rotation of solar α sunspots and implications for stellar light curves
Emily Joe Lößnitz, Alexander G. M. Pietrow, Hritam Chakraborty +5
Differential rotation is a key driver of magnetic activity and dynamo processes in the Sun and other stars, especially as the rate differs across the solar layers, but also in acti…
Spectral Background-Subtracted Activity Maps
Carsten Denker, Meetu Verma, Alexander G. M. Pietrow +2
High-resolution solar spectroscopy provides a wealth of information from photospheric and chromospheric spectral lines. However, the volume of data easily exceeds hundreds of milli…
A comparative study of two X2.2 and X9.3 solar flares observed with HARPS-N: Reconciling Sun-as-a-star spectroscopy and high-spatial resolution solar observations in the context of the solar-stellar connection
A. G. M. Pietrow, M. Cretignier, M. K. Druett +14
Stellar flares cannot be spatially resolved, which complicates ascertaining the physical processes behind particular spectral signatures. Due to their proximity to Earth, solar fla…
Wavelength Dependence of Image Quality Metrics and Seeing Parameters and their Relation to Adaptive Optics Performance
Robert Kamlah, Meetu Verma, Andrea Diercke +1
Ground-based solar observations are severely affected by Earth's turbulent atmosphere. As a consequence, observed image quality and prevailing seeing conditions are closely related…
Solar observatory Einstein Tower -- Data release of the digitized solar full-disk photographic plate archive
Partha S. Pal, M. Verma, J. Rendtel +3
We present solar full-disk observations, which were recorded at the Einstein Tower during the years 1943 - 1991 (Solar Cycles 18 - 22). High-school students from Potsdam and Berlin…
Image Quality in High-resolution and High-cadence Solar Imaging
C. Denker, E. Dineva, H. Balthasar +4
Broad-band imaging and even imaging with a moderate bandpass (about 1 nm) provides a "photon-rich" environment, where frame selection ("lucky imaging") becomes a helpful tool in im…