Sunspot positions from various historical sets of solar drawings are analysed with respect to the tilt angles of bipolar sunspot groups. Data by Scheiner, Hevelius, Staudacher, Zucconi, Schwabe, and Spoerer deliver a series of average tilt angles spanning a period of 270 years, additional to previously found values for 20th-century data obtained by other authors. We find that the average tilt angles before the Maunder minimum were not significantly different from the modern values. However, the average tilt angles of a period 50 years after the Maunder minimum, namely for cycles 0 and 1, were much lower and near zero. The normal tilt angles before the Maunder minimum suggest that it was not abnormally low tilt angles which drove the solar cycle into a grand minimum.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Sunspot group tilt angle measurements from historical observations



    Published in:

    Advances in space research ; 58 , 8 ; 1468-1474


    Publication date :

    2016




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English



    Classification :

    BKL:    50.93 / 50.93 Weltraumforschung / 55.60 Raumfahrttechnik / 55.60



    Historical sunspot observations: A review

    Vaquero, J.M. | Online Contents | 2007


    High-resolution sunspot observations

    Zirin, H. / Wang, H. | NTRS | 1991


    High-resolution sunspot observations

    Zirin, H. / Wang, H. | Elsevier | 1991


    Development of Bicycle Simulator with Tilt Angle Control Tilt Angle

    Yamaguchi, Tetsuji / Yamada, Akira / Fujiwara, Takeshi et al. | IEEE | 2018