Results 21 to 30 of about 917 (261)
Meridional motions of sunspots and sunspot groups
The Astrophysical Journal, 1986 Etude des positions des taches solaires et des groupes de taches determinees au Mont Wilson en lumiere blanche entre 1917 et 1983, afin d'examiner la nature des mouvements meridiens des taches et groupes durant cet ...
R. Howard, P. A. Gilman
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Re-examining sunspot tilt angle to include anti-Hale statistics [PDF]
, 2014 Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data ...
Li, J., McClintock, B. H., Norton, A. A.
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Research on Mount Wilson Magnetic Classification Based on Deep Learning
Advances in Astronomy, 2021 The Mount Wilson magnetic classification of sunspot groups is thought to be meaningful to forecast flares’ eruptions. In this paper, we adopt a deep learning method, CornerNet-Saccade, to perform the Mount Wilson magnetic classification of sunspot groups.
Yuanbo He +5 more
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Computer-aided measurement of the heliographic coordinates of sunspot groups
, 2021 Heliographic coordinates are used to identify the positions of solar features, especially the sunspot groups on the Sun's surface. Tracking the positions of sunspot groups provides information about solar rotation and the movement behavior of sunspot ...
Cakmak, HİKMET
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Journal of Water and Climate Change, 2021 The relation between sunspots and rainfall patterns is still obscure in Africa, especially for Sudan and South Sudan. This research explores the response of rainfall to solar activity in eastern regions of Africa, with a case study in Sudan and South ...
Mostafa A. Mohamed +1 more
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The latitudinal migration of the sunspot groups
Abstract We analyse the monthly sunspot group (SG) data for Solar Cycles C8 - C23 and calculate the average latitude of the drift path for the northern and southern hemisphere of the Sun. We find that exponential function fits slightly better than the second-order polynomial to the average drift of the SGs. The drift velocities are are 0.30 and
Takalo, Jouni J.
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Evolutionary Relationship between Sunspot Groups and Soft X-Ray Flares over Solar Cycles 21–25
The Astrophysical Journal, 2023 Studying the interaction between solar flares and sunspot groups (SGs) is crucial for understanding and predicting solar activity. We examined the distribution, correlation, and flaring rates in the northern and southern hemispheres to reveal the ...
Jiaqi Lin +5 more
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Time-dependent properties of sunspot groups. I. Lifetime and asymmetric evolution [PDF]
, 2021 Aims. In this paper, we aim to study the time dependence of sunspot group areas in a large sample composed of various databases spanning over 130 years, used state-of-the-art statistical methods. Methods.
László Dobos +5 more
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Comparison of latitude distribution and evolution of even and odd sunspot cycles [PDF]
, 2020 We study the latitudinal distribution and evolution of sunspot areas of Solar Cycles 12 – 23 (SC12–23) and sunspot groups of Solar Cycles 8 – 23 (SC8–23) for even and odd cycles.
Takalo, J. (Jouni), Takalo, Jouni
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The Development of Sunspot Groups [PDF]
International Astronomical Union Colloquium, 1993 AbstractIt is shown that the growth and decay rates of sunspot groups are both a function of the axial tilt angles of the groups. Both of these rates reach a maximum near the average tilt angle, which is around +5°, not 0°. (A positive tilt angle represents the situation where the leading spots are equatorward of the following spots).
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