TY - JOUR A1 - Arlt, Rainer A1 - Valliappan, Senthamizh Pavai A1 - Schmiel, C. A1 - Spada, F. T1 - Sunspot positions, areas, and group tilt angles for 1611-1631 from observations by Christoph Scheiner JF - Mountain research and development N2 - Methods. In most cases, the given orientation of the ecliptic is used to set up the heliographic coordinate system for the drawings. Positions and sizes are measured manually on screen. Very early drawings have no indication of their orientation. A rotational matching using common spots of adjacent days is used in some cases, while in other cases, the assumption that images were aligned with a zenith-horizon coordinate system appeared to be the most probable. KW - Sun: activity KW - sunspots KW - history and philosophy of astronomy Y1 - 2016 U6 - https://doi.org/10.1051/0004-6361/201629000 SN - 1432-0746 VL - 595 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Denker, Carsten A1 - Heibel, C. A1 - Rendtel, J. A1 - Arlt, K. A1 - Balthasar, H. A1 - Diercke, Andrea A1 - Gonzalez Manrique, Sergio Javier A1 - Hofmann, A. A1 - Kuckein, Christoph A1 - Önel, H. A1 - Valliappan, Senthamizh Pavai A1 - Staude, J. A1 - Verma, Meetu T1 - Solar physics at the Einstein Tower JF - Astronomische Nachrichten = Astronomical notes KW - history and philosophy of astronomy KW - Sun: photosphere KW - Sun: magnetic fields KW - techniques: spectroscopic KW - telescopes Y1 - 2016 U6 - https://doi.org/10.1002/asna.201612442 SN - 0004-6337 SN - 1521-3994 VL - 337 SP - 1105 EP - 1113 PB - Wiley-VCH CY - Weinheim ER -