Results 1 to 10 of about 457 (159)
Statistics of sunspot group clusters [PDF]
Journal of Space Weather and Space Climate, 2013 The Zubrzycki method is utilized to find all sunspot groups which are close to each other during each Carrington rotation. The sunspot group areas and their positions for the years 1874–2008 are used.
Getko Ryszarda
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Lifetime of Long-Lived Sunspot Groups
UniverseStudies of active region (AR) lifetimes are mostly restricted to short-lived ARs. The aim of this paper is to include recurrent ARs, which should be identified unambiguously.
Judit Muraközy
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The Astrophysical Journal Supplement Series, 2023 Angelo Secchi, an Italian Jesuit and prominent scientist of the 19th century, and one of the founders of modern astrophysics, observed the Sun regularly at the Collegio Romano in Rome, Italy, for more than 25 yr.
I. Ermolli +5 more
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The Ratio Between the Number of Sunspot and the Number of Sunspot Groups [PDF]
Geomagnetism and Aeronomy, 2017 Data from three solar observatories, Learmonth, Holloman, and San Vito, are used to study the variations in the average number of sunspots per sunspot group. It is found that the different types of sunspot groups and the number of sunspots in these groups have different solar cycle and cycle to cycle variations.
Georgieva, K. +3 more
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Change of Sunspot Groups Observed from 2002 to 2011 at ButterStar Observatory [PDF]
Journal of Astronomy and Space Sciences, 2012 Since the development of surface magnetic features should reflect the evolution of the solar magnetic field in the deep interior of the Sun, it is crucial to study properties of sunspots and sunspot groups to understand the physical processes working ...
Sung-Jin Oh, Heon-Young Chang
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Differential Rotation for Different-sized Sunspot Groups Early Observed by the OGAUC
The Astrophysical Journal, 2023 Solar differential rotation is an important ingredient of the solar dynamo model, not only because the solar rotation profile is one of the key inputs in a solar dynamo model, but also because it imposes constraints for the solar dynamo model.
Miao Wan +3 more
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Observing And Measuring Sunspots In VIS And NIR Regions [PDF]
Engineering and Technology Journal, 2010 This study is dedicated for observing and studying sunspots in the visible andnear infrared regions. Visible and near infrared CCD solar imaging system employing5 inch reflecting telescope is used.
Mohamed Saleh Ahmed, Layale Yahya Salih
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Relative Sunspot Number Observed from 2002 to 2011 at ButterStar Observatory [PDF]
Journal of Astronomy and Space Sciences, 2012 The ButterStar Observatory at the Dongducheon High School has been working for photographic observations of the Sun since October 16, 2002. In this study, we observed the Sun at the ButterStar observatory for 3,364 days from October 16, 2002 to December ...
Sung-Jin Oh, Heon-Young Chang
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Extremely large flares/multiple large flares expected from sunspot groups with large area
Earth, Planets and Space, 2022 The possible occurrence of major space weather events, such as large solar flares within one hundred years, is studied anticipating their effects on our social facilities.
Shinichi Watari
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Relationship between group sunspot numbers and Wolf sunspot numbers [PDF]
Astronomische Nachrichten, 2010 AbstractContinuous wavelet transform and cross‐wavelet transform have been used to investigate the phase periodicity and synchrony of the monthly mean Wolf (Rz) and group (Rg) sunspot numbers during the period of June 1795 to December 1995. The Schwabe cycle is the only one common period in Rg and Rz, but it is not well‐defined in case of cycles 5–7 of
Li, Kejun, Liang, Hongfei
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