The Butterfly Diagram in the Eighteenth Century |
| |
Authors: | R Arlt |
| |
Institution: | (1) Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany |
| |
Abstract: | Digitized images of the drawings by J.C. Staudacher were used to determine sunspot positions for the period 1749 – 1796. From
the entire set of drawings, 6285 sunspot positions were obtained for a total of 999 days. Various methods have been applied
to find the orientation of the solar disk, which is not given for the vast majority of the drawings by Staudacher. Heliographic
latitudes and longitudes in the Carrington rotation frame were determined. The resulting butterfly diagram shows a highly-populated
Equator during the first two cycles (cycles 0 and 1 in the usual counting since 1749). An intermediate period is cycle 2,
whereas cycles 3 and 4 show a typical butterfly shape. A tentative explanation may be the transient dominance of a quadrupolar
magnetic field during the first two cycles. |
| |
Keywords: | Sun: sunspots Sun: magnetic field |
本文献已被 SpringerLink 等数据库收录! |
|