52 citations · 73 across the 5 of their papers we have counts for
5 papers
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…
Stellar surface information from the Ca II H&K lines I. Intensity profiles of the solar activity components
M. Cretignier, A. G. M. Pietrow, S. Aigrain
The detection of Earth-like planets with the radial-velocity method is currently limited by the presence of stellar activity signatures. On rotational timescales, spots and plages…
Solar oxygen abundance using SST/CRISP center-to-limb observations of the O I 7772 Å line
A. G. M. Pietrow, R. Hoppe, M. Bergemann +1
Solar oxygen abundance measurements based on the O I near-infrared triplet have been a much-debated subject for several decades since non-local thermodynamic equilibrium (NLTE) cal…
Did Christiaan Huygens need glasses? A study of Huygens' telescope equations and tables
A. G. M. Pietrow
In the later stages of his life, Christiaan Huygens semi-empirically derived a set of relations between the objective focus and diameter, the eyepiece focus, and the magnification…
The coronagraphic Modal Wavefront Sensor: a hybrid focal-plane sensor for the high-contrast imaging of circumstellar environments
Michael J. Wilby, Christoph U. Keller, Frans Snik +2
The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental no…