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arXiv · 2007.14744

Solar observatory Einstein Tower -- Data release of the digitized solar full-disk photographic plate archive

Partha S. Pal·M. Verma·J. Rendtel·S. J. González Manrique·H. Enke·C. Denker
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Abstract

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 digitized more than 3500 full-disk images during two- to three-week internships at AIP. The digital images cover a 15 cm $\times$ 15 cm region on photographic plates, which were scanned at a resolution of 7086 $\times$ 7086 pixels. The raw data are monochromatic 8-bit images in the Tagged Image File Format (TIFF). These images were calibrated and saved with improved photometric precision as 16-bit images with 2048 $\times$ 2048 pixels in the Flexible Image Transport System (FITS) format, which contains extensive headers describing the full-disk images and the observations. The various calibration steps include, for example, accurate measurements of the solar radius, determination of the limb-darkening function, and establishing an accurate coordinate system. The contrast-enhanced and limb-darkening corrected images as well as the raw data are freely available to researchers and the general public in publicly accessible repository. The data are published as a special data release of the Archives of Photographic PLates for Astronomical USE (APPLAUSE) project.

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Partha S. Pal, M. Verma, J. Rendtel, S. J. González Manrique, H. Enke, C. Denker. 2020-07-29. Solar observatory Einstein Tower -- Data release of the digitized solar full-disk photographic plate archive. https://doi.org/10.1002/asna.202013791

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