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longer-term trends in TSI lies in the stability of the absolute radiometry measurements made from space, which has improved in recent decades but remains a problem. Analysis shows that it is possible that TSI was actually higher in the
Maunder Minimum compared to present-day levels, but uncertainties are high, with best estimates in the range
742:
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699:. The umbra may be surrounded completely or only partially by a brighter region known as the penumbra. The penumbra is composed of radially elongated structures known as penumbral filaments and has a more inclined magnetic field than the umbra. Within sunspot groups, multiple umbrae may be surrounded by a single, continuous penumbra.
857:
Solar cycles last typically about eleven years, varying from just under 10 to just over 12 years. Over the solar cycle, sunspot populations increase quickly and then decrease more slowly. The point of highest sunspot activity during a cycle is known as solar maximum, and the point of lowest activity
494:
Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay. Sunspots expand and contract as they move across the surface of the Sun, with diameters ranging from 16 km (10 mi) to 160,000 km (100,000 mi). Larger sunspots can be
2056:
Felipe, T.; Collados, M.; Khomenko, E.; Kuckein, C.; Asensio Ramos, A.; Balthasar, H.; Berkefeld, T.; Denker, C.; Feller, A.; Franz, M.; Hofmann, A.; Joshi, J.; Kiess, C.; Lagg, A.; Nicklas, H.; Orozco Suárez, D.; Pastor Yabar, A.; Rezaei, R.; Schlichenmaier, R.; Schmidt, D.; Schmidt, W.; Sigwarth,
644:
was one of the first to equate sunspots with heating and cooling on Earth and believed that certain features of sunspots would indicate increased heating on Earth. During his recognition of solar behavior and hypothesized solar structure, he inadvertently picked up the relative absence of sunspots
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In some forming and decaying sunspots, relatively narrow regions of bright material appear penetrating into or completely dividing an umbra. These formations, referred to as light bridges, have been found to have a weaker, more tilted magnetic field compared to the umbra at the same height in the
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Sunspots initially appear in the photosphere as small darkened spots lacking a penumbra. These structures are known as solar pores. Over time, these pores increase in size and move towards one another. When a pore gets large enough, typically around 3,500 km (2,000 mi) in diameter, a
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and the chromospheric network. The combination of these magnetic factors mean that the relationship of sunspot numbers to Total Solar
Irradiance (TSI) over the decadal-scale solar cycle, and their relationship for century timescales, need not be the same. The main problem with quantifying the
1123:
Sunspots themselves, in terms of the magnitude of their radiant-energy deficit, have a weak effect on solar flux. The total effect of sunspots and other magnetic processes in the solar photosphere is an increase of roughly 0.1% in brightness of the Sun in comparison with its brightness at the
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in Europe. However, detailed studies from multiple paleoclimate indicators show that the lower northern hemisphere temperatures in the Little Ice Age began while sunspot numbers were still high before the start of the
Maunder Minimum, and persisted until after the Maunder Minimum had ceased.
1336:
showed differential rotation of spots for several stars and distributions different from the Sun's; spectral line analysis measured the temperature range of spots and the stellar surfaces. For example, in 1999, Strassmeier reported the largest cool starspot ever seen rotating the giant
920:
over the period since 1979, when satellite measurements became available. The variation caused by the sunspot cycle to solar output is on the order of 0.1% of the solar constant (a peak-to-trough range of 1.3 W·m compared with 1366 W·m for the average solar constant).
838:
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International
Sunspot Number – sunspot maximum and minimum 1610–present; annual numbers 1700–present; monthly numbers 1749–present; daily values 1818–present; and sunspot numbers by north and south hemisphere. The McNish–Lincoln sunspot prediction is also
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first linked magnetic fields and sunspots in 1908. Hale suggested that the sunspot cycle period is 22 years, covering two periods of increased and decreased sunspot numbers, accompanied by polar reversals of the solar magnetic
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from July 1795 to
January 1800 and was perhaps the first to construct a past record of observed or missing sunspots. From this he found that the absence of sunspots coincided with high wheat prices in England. The president of the
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in the photosphere. As a result, the energy flux from the Sun's interior decreases, and with it, surface temperature, causing the surface area through which the magnetic field passes to look dark against the bright background of
1962:"XIII. Observations tending to investigate the nature of the sun, in order to find the causes or symptoms of its variable emission of light and heat; with remarks on the use that may possibly be drawn from solar observations"
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Sunspots, with their intense magnetic field concentrations, facilitate the complex transfer of energy and momentum to the upper solar atmosphere. This transfer occurs through a variety of mechanisms, including generated
841:
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869:. Spots from two sequential cycles co-exist for several years during the years near solar minimum. Spots from sequential cycles can be distinguished by direction of their magnetic field and their latitude.
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were observed in the sun, where both words refer to a small obscuration. The earliest record of a deliberate sunspot observation also comes from China, and dates to 364 BC, based on comments by astronomer
875:
sunspot index counts the average number of sunspots and groups of sunspots during specific intervals. The 11-year solar cycles are numbered sequentially, starting with the observations made in the 1750s.
661:
in 1884 tried and failed to find a connection between wheat prices and sunspots, and modern analysis finds that there is no statistically significant correlation between wheat prices and sunspot numbers.
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tend to last weeks or months. Sunspots expand and contract as they move across the surface of the Sun, with diameters ranging from 16 km (10 mi) to 160,000 km (100,000 mi).
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710:(closely approximated by the photosphere) at these temperatures varies greatly with temperature. Isolated from the surrounding photosphere, a single sunspot would shine brighter than the full
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A decaying sunspot shown over the course of two hours. The umbra is separated into two pieces within the penumbra by a light bridge. Solar pores are also visible to the left of the penumbra.
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The temperature of the umbra is roughly 3000–4500 K, in contrast to the surrounding material at about 5780 K, leaving sunspots clearly visible as dark spots. This is because the
807:) were used to develop a three-dimensional image of the internal structure below sunspots; these observations show that a powerful downdraft lies beneath each sunspot, forms a rotating
1089:. High sunspot activity is celebrated by members of the amateur radio community as a harbinger of excellent ionospheric propagation conditions that greatly increase radio range in the
955:
and Dalton minima, and the Modern
Maximum (left) and 11,000-year sunspot reconstruction showing a downward trend over 2000 BC – 1600 AD followed by the recent 400 year uptrend
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trend of sunspot count was upwards; for the following 60 years the trend was mostly downwards. Overall, the Sun was last as active as the modern maximum over 8,000 years ago.
629:. After Johannes Fabricius' death at the age of 29, his reports remained obscure and were overshadowed by the independent discoveries of and publications about sunspots by
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starspots vary on the same (short) time scales as
Sunspots do ... HD 12545 had a warm spot (350 K above photospheric temperature; the white area in the picture)
744:
1245:
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should tend to remove field concentrations, causing the sunspots to disperse, but sunspot lifetimes are measured in days to weeks. In 2001, observations from the
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can project the image, without filtration, onto a white screen where it can be viewed indirectly, and even traced, to follow sunspot evolution. Special purpose
1011:. These telescopes use filtration and projection techniques for direct observation, in addition to various types of filtered cameras. Specialized tools such as
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1019:
are used to examine sunspots and sunspot areas. Artificial eclipses allow viewing of the circumference of the Sun as sunspots rotate through the horizon.
3201:
2934:"Placing limits on long-term variations in quiet-Sun irradiance and their contribution to total solar irradiance and solar radiative forcing of climate"
44:
767:
Although the details of sunspot formation are still a matter of ongoing research, it is widely understood that they are the visible manifestations of
1848:
The Sun
Recorded Through History: Scientific Data Extracted from Historical Documents vol. 361 of the series Astrophysics and Space Science Library
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explains that magnetic fields cause the behavior described by Spörer's law, as well as other effects, which are twisted by the Sun's rotation.
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projecting through the photosphere within active regions. Their characteristic darkening occurs due to this strong magnetic field inhibiting
637:. Galileo likely began telescopic sunspot observations around the same time as Harriot; however, Galileo's records did not start until 1612.
1816:
2165:
Mathew, S. K.; Lagg, A.; Solanki, S. K.; Collados, M.; Borrero, J. M.; Berdyugina, S.; Krupp, N.; Woch, J.; Frutiger, C. (November 2003).
2057:
M.; Sobotka, M.; Solanki, S. K.; Soltau, D.; Staude, J.; Strassmeier, K. G.; Volkmer, R.; von der Lühe, O.; Waldmann, T. (December 2016).
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The appearance of an individual sunspot may last anywhere from a few days to a few months, though groups of sunspots and their associated
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Early in the cycle, sunspots appear at higher latitudes and then move towards the equator as the cycle approaches maximum, following
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1324:. Since the mid-1990s, starspot observations have been made using increasingly powerful techniques yielding more and more detail:
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Sunspot
Database based on Terrestrial (GPR/DPD) and Satellite (SOHO/SDO) observations from 1872 to Nowadays with the newest data.
909:
Sunspot numbers also change over long periods. For example, during the period known as the modern maximum from 1900 to 1958 the
2795:
Willson, R. C.; Gulkis, S.; Janssen, M.; Hudson, H. S.; Chapman, G. A. (1981). "Observations of solar irradiance variability".
2206:
2000:
Soon, W., and
Yaskell, S.H., The Maunder Minimum and the Variable Sun-earth Connection (World Scientific Press: 2003) pp. 87–88
1345:(HD 12545) with a temperature of 3,500 K (3,230 °C), together with a warm spot of 4,800 K (4,530 °C).
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photosphere. Higher in the photosphere, the light bridge magnetic field merges and becomes comparable to that of the umbra.
691:. The umbra is the darkest region of a sunspot and is where the magnetic field is strongest and approximately vertical, or
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originate in these magnetically active regions around visible sunspot groupings. Similar phenomena indirectly observed on
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examined the structure of starspot regions by analyzing variations in spectral line splitting due to the Zeeman effect;
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that are darker than the surrounding area. They are regions of reduced surface temperature caused by concentrations of
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bands. During peaks in sunspot activity, worldwide radio communication can be achieved on frequencies as high as the
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1100:
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Sobotka, Michal; Vazquez, Manuel; Bonet, Jose Antonio; Hanslmeier, Arnold; Hirzberger, Johann (20 January 1999).
617:. His observations were recorded in his notebooks and were followed in March 1611 by observations and reports by
2676:
1523:
1030:, amateur observation of sunspots is generally conducted using projected images, or directly through protective
4012:
297:
277:
31:
3172:
1599:
Xu Zhen-Tao (1980). "The hexagram "Feng" in "the book of changes" as the earliest written record of sunspot".
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969:. There are two prominent peaks corresponding to its 11-year cycle and its 27-day cycle due to solar rotation.
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3574:
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1086:
989:
781:
576:. By 28 BC, Chinese astronomers were regularly recording sunspot observations in official imperial records.
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2697:"The Maunder Minimum and the Little Ice Age: An update from recent reconstructions and climate simulations"
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1338:
1325:
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3421:
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Jess, D. B., Jafarzadeh, S., Keys, P. H., Stangalini, M., Verth, G., Grant, S. D. T. (19 January 2023).
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Comparison of the Variations of Sunspot Number, Number of Sunspot Groups, and Sunspot Area, 1875–2013
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2019:
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Catchers of the Light: The Forgotten Lives of the Men and Women Who First Photographed the Heavens
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and is linked to a variation in the solar magnetic field that changes polarity with this period.
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Indicating intense magnetic activity, sunspots accompany other active region phenomena such as
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2010:
Love, Jeffrey J. (27 August 2013). "On the insignificance of Herschel's sunspot correlation".
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3394:. Huntsville, AL: National Aeronautics and Space Administration, Marshall Space Flight Center
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Bottom: a large group of sunspots stretching about 320,000 km (200,000 mi) across.
3308:"Unusual activity of the Sun during recent decades compared with the previous 11,000 years"
3234:
An educational resource for teachers and students about the Sun and its effect on the Earth
2167:"Three dimensional structure of a regular sunspot from the inversion of IR Stokes profiles"
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Kopp, G. (July 2016). "Magnitudes and timescales of total solar irradiance variability".
2446:"Unusual activity of the Sun during recent decades compared to the previous 11,000 years"
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Numerical climate modelling indicates that volcanic activity was the main driver of the
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2999:"Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes"
2507:
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later proposed a qualitative model for the dynamics of the solar outer layers. The
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Sunspots were first observed telescopically in December 1610 by English astronomer
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131:
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2125:
2124:
Schlichenmaier, R.; Rezaei, R.; Bello González, N.; Waldmann, T. A. (March 2010).
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showed starspot growth and decay and showed cyclic behavior similar to the Sun's;
2816:
2560:
Le Mouël, Jean-Louis; Shnirman, Mikhail G.; Blanter, Elena M. (1 December 2007).
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Middle: sunspot close-up in the visible spectrum (left) and another sunspot in
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2755:
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1938:
1855:
1358:– empirical law for the orientation of magnetic fields in solar active regions
1321:
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247:
242:
3246:
HamLinks Toolbar – displays solar flux, A Index and K Index data in a toolbar
3143:
2965:
2732:
2593:
1770:
1742:
1058:) on the front of a telescope provide safe observation through the eyepiece.
3721:
3594:
3245:
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1914:
1567:"Smallest KPNO Telescope Discovers Biggest Starspots (press release 990610)"
1023:
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73:
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Solanki SK; Usoskin IG; Kromer B; Schüssler M; et al. (October 2004).
1978:
1961:
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filters (which have the appearance of mirrors due to their extremely high
3863:
3072:
3047:
1407:
1317:
1311:
1172:. Other magnetic phenomena which correlate with sunspot activity include
1039:
997:
751:
The emergence and evolution of a sunspot group over a period of two weeks
618:
535:
332:
2469:
1364:– empirical law for the distribution of sunspots in solar active regions
17:
3082:
2933:
2696:
2422:
1043:
555:
2031:
684:
3389:
884:
808:
569:
317:
3128:
Carl Luetzelschwab, K9LA (October 2016). "The new sunspot numbers".
1691:
Letter to the Editor: Sunspot observations by Theophrastus revisited
3955:
3240:
3015:
2893:
2713:
2531:"The Discovery of Global Warming – Changing Sun, Changing Climate?"
2407:
2382:
2306:
2078:
3258:
Daily Sunspot Update and Picture of the Sun (www.spaceweather.com)
2840:"An assessment of the solar irradiance record for climate studies"
1915:"Sunspot Positions and Areas from Observations by Galileo Galilei"
983:
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The full solar disk over the course of 13 days during the rise of
836:
824:
740:
674:
592:
96:
Top: active region 2192 in 2014 containing the largest sunspot of
2562:"The 27-Day Signal in Sunspot Number Series and the Solar Dynamo"
2280:"Temporal Evolution of Fine Structures in and around Solar Pores"
1771:"Sunspot Positions and Areas from Observations by Thomas Harriot"
3858:
3241:
Propfire – displays current sunspot number in browser status bar
3189:
803:(SOHO) using sound waves traveling below the photosphere (local
711:
531:
3410:
3257:
3437:
3329:"Sunspot Numbers from Ancient Times to Present from NOAA/NGDC"
3130:
1635:"Early Astronomy and the Beginnings of a Mathematical Science"
1634:
159:
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as solar minimum. This period is also observed in most other
507:, of a few hundred meters per second when they first emerge.
487:. Their number varies according to the approximately 11-year
3185:
Solar Cycle 24 and VHF Aurora Website (www.solarcycle24.com)
3098:"Derived images showing rotation of cool and warm starspots"
2383:"On the Probable Existence of a Magnetic Field in Sun-Spots"
733:
implies that sunspots are depressions on the Sun's surface.
1038:, such as a #14 welder's glass, are effective. A telescope
649:
commented that the upward trend in wheat prices was due to
3406:
2504:
Climate Change 2001: Working Group I: The Scientific Basis
2235:
Solanki, Sami K. (1 April 2003). "Sunspots: An overview".
1882:
Storms from the Sun: The Emerging Science of Space Weather
1103:(and the solar cycle) have been implicated as a factor in
3380:
Group Sunspot Numbers (Doug Hoyt re-evaluation) 1610–1995
3237:
Tools to display the current sunspot number in a browser
2368:
The Space Environment, Implications for Spacecraft Design
1966:
Philosophical Transactions of the Royal Society of London
1769:
Vokhmyanin, M.; VArlt, R.; Zolotova, N. (10 March 2020).
1111:
period of low sunspot activity which occurred during the
1007:
Sunspots are observed with land-based and Earth-orbiting
3226:
2337:"SOHO reveals how sunspots take stranglehold on the Sun"
553:
The earliest record of sunspots is found in the Chinese
2059:"Three-dimensional structure of a sunspot light bridge"
1320:
were the reason for periodic changes in brightness on
722:
in light bridges has also been found to dominate over
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1253:
1230:
1183:
1134:
559:, completed before 800 BC. The text describes that a
3100:. Leibniz Institute for Astrophysics. Archived from
965:
The daily sunspot number from 1945 to 2017, and its
538:, and both light and dark spots have been measured.
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3627:
3565:
3537:
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Animated explanation of Sunspots in the Photosphere
1528:
Quarterly Journal of the Royal Astronomical Society
1124:solar-minimum level. This is a difference in total
916:Sunspot number is correlated with the intensity of
1286:
1239:
1216:
1164:
1817:"Great Moments in the History of Solar Physics 1"
1217:{\displaystyle \pm 0.5\ \mathrm {W\cdot m^{-2}} }
1913:Vokhmyanin, M.; Zolotova, N. (5 February 2018).
3190:Belgium World Data Center for the sunspot index
1495:
1493:
1287:{\displaystyle \pm 1\ \mathrm {W\cdot m^{-2}} }
811:that sustains the concentrated magnetic field.
2634:Eddy J.A. (June 1976). "The Maunder Minimum".
1476:"How Are Magnetic Fields Related To Sunspots?"
1165:{\displaystyle 1.37\ \mathrm {W\cdot m^{-2}} }
3422:
3048:"Solar Flares: Magnetohydrodynamic Processes"
2529:Weart, Spencer (2006). Weart, Spencer (ed.).
2370:. Princeton University Press. pp. 15–18.
1821:Great Moments in the History of Solar Physics
1560:
1558:
1556:
1066:Due to their correlation with other kinds of
726:, and convective motions have been detected.
683:Sunspots have two main structures: a central
445:
8:
3046:Shibata, K., Magara, T. (15 December 2011).
2230:
2228:
1879:Carlowicz, Michael J.; López, Ramón (2002).
1128:at Earth over the sunspot cycle of close to
1107:. The first possible example of this is the
3284:"11,000 Year Sunspot Number Reconstruction"
3156:: CS1 maint: numeric names: authors list (
3058:(1). Springer International Publishing: 6.
2051:
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1022:Since looking directly at the Sun with the
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3415:
3407:
3227:Lockheed Martin Solar and Astrophysics Lab
452:
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2695:Owens, M.J.; et al. (October 2017).
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1977:
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1707:Stephenson, F. R.; Willis, D. M. (1999).
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1229:
1204:
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100:and active region 1302 in September 2011.
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579:The first clear mention of a sunspot in
546:For broader coverage of this topic, see
495:visible from Earth without the aid of a
3939:
3209:Impressive collection of sunspot images
2425:. Solar Influences Data Analysis Center
1428:
1070:, sunspots can be used to help predict
534:other than the Sun are commonly called
130:
3377:Ancient sunspot data 165 BC to 1684 AD
3149:
2611:. Ham Radio School.com. Archived from
1960:Herschel, William (31 December 1801).
1885:. Joseph Henry Press. pp. 1–382.
1693:", and see Theophrastus' Fragment VI,
3374:American sunspot numbers 1945–present
2335:NASA News Release (6 November 2001).
2126:"The formation of a sunspot penumbra"
1850:. Vol. 361. Springer, New York.
7:
2209:. NASA. 1 April 1998. Archived from
27:Temporary spots on the Sun's surface
2932:Lockwood, M.; Ball, W. (May 2020).
1759:, ArtDeCiel Publishing, 2012 p. 317
1565:Strassmeier, K. G. (10 June 1999).
1300:waves in the lower solar atmosphere
2938:Proceedings of the Royal Society A
2881:J. Space Weather and Space Climate
2844:J. Space Weather and Space Climate
2701:J. Space Weather and Space Climate
1846:Vaquero, J.M.; Vázquez, M (2009).
1709:"The earliest drawing of sunspots"
1437:"Gentle giant sunspot region 2192"
1316:In 1947, G. E. Kron proposed that
1302:and magnetic reconnection events.
1271:
1264:
1201:
1194:
1149:
1142:
994:Roque de los Muchachos Observatory
801:Solar and Heliospheric Observatory
126:Part of a series of articles about
25:
2237:Astronomy and Astrophysics Review
829:Butterfly diagram showing paired
653:. Years later scientists such as
3990:
3978:
3966:
3954:
3942:
3917:
3916:
3388:Wilson, Robert M. (April 2014).
3176:
937:
928:
905:Solar cycle § Cycle history
83:
72:
63:
52:
43:
3052:Living Reviews in Solar Physics
3003:Living Reviews in Solar Physics
1639:NRICH (University of Cambridge)
714:, with a crimson-orange color.
483:, usually in pairs of opposite
3333:Global Change Master Directory
3288:Global Change Master Directory
1503:. HowStuffWorks. 22 April 2009
1034:. Small sections of very dark
1:
3899:List of heliophysics missions
3357:NOAA NGDC Solar Data Services
3253:The Sharpest View of the Sun
3202:High resolution sunspot image
2656:10.1126/science.192.4245.1189
2535:American Institute of Physics
1661:"The Observation of Sunspots"
1524:"1989QJRAS..30...59M Page 60"
1078:, and conditions relevant to
788:penumbra will begin to form.
599:and successor to the latter.
3904:Category:Missions to the Sun
3213:NOAA Solar Cycle Progression
2817:10.1126/science.211.4483.700
2171:Astronomy & Astrophysics
2066:Astronomy & Astrophysics
2012:Geophysical Research Letters
1621:10.1016/0146-6364(80)90034-1
1046:narrow bandpass filters and
3272:(University of South Wales)
2151:10.1051/0004-6361/201014112
2096:10.1051/0004-6361/201629586
990:Swedish 1-m Solar Telescope
695:, to the Sun's surface, or
640:In the early 19th Century,
467:are temporary spots on the
4034:
3207:Sunspot images in high-res
3033:10.1007/s41116-022-00035-6
2609:"Sunspots and Propagation"
2500:"Solar Forcing of Climate"
2192:10.1051/0004-6361:20031282
2130:Astronomy and Astrophysics
1795:10.1007/s11207-020-01604-4
1713:Astronomy & Geophysics
1309:
977:
902:
818:
606:were made by English monk
545:
145:Heliospheric current sheet
29:
3912:
3880:G-type main-sequence star
3444:
2781:10.4249/scholarpedia.3967
2586:10.1007/s11207-007-9065-8
2387:The Astrophysical Journal
2287:The Astrophysical Journal
2257:10.1007/s00159-003-0018-4
1939:10.1007/s11207-018-1245-1
1856:10.1007/978-0-387-92790-9
479:. Sunspots appear within
3743:In mythology and culture
3312:WDC for Paleoclimatology
3268:16 November 2015 at the
2682:16 February 2010 at the
2423:"Sunspot index graphics"
1734:10.1093/astrog/40.6.6.21
1240:{\displaystyle 2\sigma }
1087:satellite communications
298:Van Allen radiation belt
32:Sunspot (disambiguation)
3215:: Current solar cycle.
2838:Kopp, G. (April 2014).
2249:2003A&ARv..11..153S
2183:2003A&A...410..695M
2142:2010A&A...512L...1S
2088:2016A&A...596A..59F
1725:1999A&G....40f..21S
1522:Mossman, J. E. (1989).
3610:Supra-arcade downflows
3009:(1). Springer Nature.
2958:10.1098/rspa.2020.0077
1979:10.1098/rstl.1801.0015
1667:. 1988. Archived from
1288:
1241:
1218:
1166:
1004:
970:
854:
834:
752:
680:
528:coronal mass ejections
3590:Coronal mass ejection
3195:3 August 2017 at the
1695:De Signis Tempestatum
1289:
1247:uncertainty range of
1242:
1219:
1167:
987:
964:
849:
828:
782:photospheric granules
750:
678:
499:. They may travel at
226:Interplanetary medium
208:Particle acceleration
201:Magnetic reconnection
3854:Standard solar model
3824:Solar radio emission
3642:List of solar cycles
3339:on 14 September 2015
3218:Current conditions:
3073:10.12942/lrsp-2011-6
2911:10.1051/swsc/2016025
2865:10.1051/swsc/2014012
2724:10.1051/swsc/2017019
2381:Hale, G. E. (1908).
2366:Tribble, A. (2003).
1571:University of Vienna
1375:List of solar cycles
1251:
1228:
1181:
1132:
1026:permanently damages
947:400-year history of
899:Longer-period trends
604:drawings of sunspots
583:is circa 300 BC, by
419:Solar particle event
30:For other uses, see
3674:Magnetic switchback
3064:2011LRSP....8....6S
3025:2023LRSP...20....1J
2950:2020RSPSA.47600077L
2903:2016JSWSC...6A..30K
2856:2014JSWSC...4A..14K
2809:1981Sci...211..700W
2772:2008SchpJ...3.3967H
2648:1976Sci...192.1189E
2642:(4245): 1189–1202.
2578:2007SoPh..246..295L
2470:10.1038/nature02995
2462:2004Natur.431.1084S
2456:(7012): 1084–1087.
2399:1908ApJ....28..315H
2299:1999ApJ...511..436S
2024:2013GeoRL..40.4171L
1931:2018SoPh..293...31V
1787:2020SoPh..295...39V
1613:1980ChA.....4..406X
1540:1989QJRAS..30...59M
1369:Letters on Sunspots
1074:, the state of the
769:magnetic flux tubes
659:John Henry Poynting
602:The earliest known
355:Flux transfer event
3864:Sunlight radiation
3459:Internal structure
3294:on 2 November 2015
2944:(2238): 20200077.
2347:on 17 January 2015
1284:
1237:
1214:
1162:
1017:spectrohelioscopes
1005:
974:Modern observation
971:
880:George Ellery Hale
855:
835:
753:
687:and a surrounding
681:
655:Richard Carrington
651:monetary inflation
631:Christoph Scheiner
610:in December 1128.
581:Western literature
3930:
3929:
3894:Solar observatory
3809:Solar observation
3707:Termination shock
3623:
3622:
3575:Transition region
3353:"Sunspot Numbers"
2803:(4483): 700–702.
2754:Hudson H (2008).
2032:10.1002/grl.50846
2018:(16): 4171–4176.
1925:(2): 31.1–31.21.
1865:978-0-387-92789-3
1781:(3): 39.1–39.11.
1601:Chinese Astronomy
1380:Radio propagation
1262:
1192:
1140:
1083:radio propagation
980:Solar observatory
889:Horace W. Babcock
847:
797:Magnetic pressure
748:
724:magnetic pressure
608:John of Worcester
548:Solar observation
485:magnetic polarity
462:
461:
308:Birkeland current
16:(Redirected from
4025:
3995:
3994:
3993:
3983:
3982:
3981:
3971:
3970:
3969:
3959:
3958:
3947:
3946:
3945:
3938:
3920:
3919:
3509:Supergranulation
3497:
3431:
3424:
3417:
3408:
3403:
3401:
3399:
3367:
3365:
3363:
3348:
3346:
3344:
3335:. Archived from
3322:
3320:
3318:
3303:
3301:
3299:
3290:. Archived from
3232:Sun|trek website
3180:
3179:
3161:
3155:
3147:
3114:
3113:
3111:
3109:
3094:
3088:
3087:
3085:
3075:
3043:
3037:
3036:
3018:
2994:
2988:
2987:
2977:
2929:
2923:
2922:
2896:
2876:
2870:
2869:
2867:
2835:
2829:
2828:
2792:
2786:
2785:
2783:
2756:"Solar activity"
2751:
2745:
2744:
2726:
2716:
2692:
2686:
2675:
2631:
2625:
2624:
2622:
2620:
2604:
2598:
2597:
2557:
2551:
2550:
2548:
2546:
2537:. Archived from
2526:
2520:
2519:
2517:
2515:
2510:on 15 March 2005
2506:. Archived from
2496:
2490:
2489:
2441:
2435:
2434:
2432:
2430:
2419:
2413:
2412:
2410:
2378:
2372:
2371:
2363:
2357:
2356:
2354:
2352:
2343:. Archived from
2332:
2326:
2325:
2323:
2321:
2284:
2275:
2269:
2268:
2243:(2–3): 153–286.
2232:
2223:
2222:
2220:
2218:
2203:
2197:
2196:
2194:
2162:
2156:
2155:
2153:
2121:
2115:
2114:
2112:
2110:
2081:
2063:
2053:
2044:
2043:
2007:
2001:
1998:
1992:
1991:
1981:
1957:
1951:
1950:
1910:
1904:
1903:
1901:
1899:
1876:
1870:
1869:
1843:
1837:
1836:
1834:
1832:
1823:. Archived from
1813:
1807:
1806:
1766:
1760:
1753:
1747:
1746:
1736:
1719:(6): 6.21–6.22.
1704:
1698:
1687:
1681:
1680:
1678:
1676:
1657:
1651:
1650:
1648:
1646:
1631:
1625:
1624:
1596:
1590:
1589:
1584:
1582:
1573:. Archived from
1562:
1551:
1550:
1548:
1546:
1519:
1513:
1512:
1510:
1508:
1497:
1488:
1487:
1485:
1483:
1472:
1463:
1462:
1460:
1458:
1447:
1441:
1440:
1433:
1417:
1404:
1293:
1291:
1290:
1285:
1283:
1282:
1281:
1260:
1246:
1244:
1243:
1238:
1223:
1221:
1220:
1215:
1213:
1212:
1211:
1190:
1171:
1169:
1168:
1163:
1161:
1160:
1159:
1138:
1126:solar irradiance
1095:6-meter VHF band
1009:solar telescopes
941:
932:
848:
749:
642:William Herschel
454:
447:
440:
407:Solar prominence
258:Forbush decrease
142:
123:
87:
76:
67:
56:
47:
21:
4033:
4032:
4028:
4027:
4026:
4024:
4023:
4022:
4013:Solar phenomena
4003:
4002:
4001:
3991:
3989:
3979:
3977:
3967:
3965:
3953:
3943:
3941:
3933:
3931:
3926:
3908:
3882:
3868:
3834:Solar telescope
3814:Solar phenomena
3789:Solar astronomy
3726:
3688:
3684:Helioseismology
3619:
3605:Helmet streamer
3561:
3533:
3486:
3482:Convection zone
3453:
3440:
3435:
3397:
3395:
3387:
3361:
3359:
3351:
3342:
3340:
3327:
3316:
3314:
3306:
3297:
3295:
3282:
3279:
3270:Wayback Machine
3197:Wayback Machine
3169:
3164:
3148:
3127:
3123:
3121:Further reading
3118:
3117:
3107:
3105:
3096:
3095:
3091:
3045:
3044:
3040:
2996:
2995:
2991:
2931:
2930:
2926:
2878:
2877:
2873:
2837:
2836:
2832:
2794:
2793:
2789:
2753:
2752:
2748:
2694:
2693:
2689:
2684:Wayback Machine
2633:
2632:
2628:
2618:
2616:
2615:on 26 June 2017
2606:
2605:
2601:
2559:
2558:
2554:
2544:
2542:
2541:on 17 June 2006
2528:
2527:
2523:
2513:
2511:
2498:
2497:
2493:
2443:
2442:
2438:
2428:
2426:
2421:
2420:
2416:
2380:
2379:
2375:
2365:
2364:
2360:
2350:
2348:
2341:SpaceFlight Now
2334:
2333:
2329:
2319:
2317:
2282:
2277:
2276:
2272:
2234:
2233:
2226:
2216:
2214:
2213:on 3 April 2013
2205:
2204:
2200:
2164:
2163:
2159:
2123:
2122:
2118:
2108:
2106:
2061:
2055:
2054:
2047:
2009:
2008:
2004:
1999:
1995:
1959:
1958:
1954:
1912:
1911:
1907:
1897:
1895:
1893:
1878:
1877:
1873:
1866:
1845:
1844:
1840:
1830:
1828:
1827:on 1 March 2006
1815:
1814:
1810:
1768:
1767:
1763:
1755:Stefan Hughes,
1754:
1750:
1706:
1705:
1701:
1688:
1684:
1674:
1672:
1659:
1658:
1654:
1644:
1642:
1633:
1632:
1628:
1598:
1597:
1593:
1580:
1578:
1577:on 24 June 2010
1564:
1563:
1554:
1544:
1542:
1521:
1520:
1516:
1506:
1504:
1499:
1498:
1491:
1481:
1479:
1474:
1473:
1466:
1456:
1454:
1449:
1448:
1444:
1435:
1434:
1430:
1425:
1420:
1415:
1402:
1351:
1334:Doppler imaging
1314:
1308:
1270:
1249:
1248:
1226:
1225:
1200:
1179:
1178:
1148:
1130:
1129:
1109:Maunder Minimum
1064:
1056:optical density
1048:aluminum-coated
982:
976:
959:
958:
957:
956:
949:sunspot numbers
944:
943:
942:
934:
933:
918:solar radiation
907:
901:
873:The Wolf number
837:
823:
817:
805:helioseismology
794:
773:convective zone
765:
741:
739:
673:
668:
635:Galileo Galilei
627:David Fabricius
551:
544:
501:relative speeds
458:
429:
428:
370:
368:Solar phenomena
360:
359:
343:Space hurricane
283:Particle motion
273:
271:Magnetospherics
263:
262:
228:
218:
217:
213:Nuclear physics
186:
147:
121:
120:
119:
118:
117:
107:, taken by the
90:
89:
88:
79:
78:
77:
69:
68:
59:
58:
57:
49:
48:
35:
28:
23:
22:
15:
12:
11:
5:
4031:
4029:
4021:
4020:
4015:
4005:
4004:
4000:
3999:
3987:
3975:
3963:
3951:
3928:
3927:
3925:
3924:
3913:
3910:
3909:
3907:
3906:
3901:
3896:
3890:
3888:
3884:
3883:
3878:
3876:
3874:Spectral class
3870:
3869:
3867:
3866:
3861:
3856:
3851:
3846:
3841:
3836:
3831:
3826:
3821:
3816:
3811:
3806:
3804:Solar neutrino
3801:
3796:
3791:
3786:
3784:Solar activity
3781:
3779:Sun in fiction
3776:
3775:
3774:
3773:
3772:
3757:
3752:
3751:
3750:
3745:
3734:
3732:
3728:
3727:
3725:
3724:
3719:
3714:
3709:
3704:
3698:
3696:
3690:
3689:
3687:
3686:
3681:
3676:
3671:
3666:
3661:
3656:
3651:
3646:
3645:
3644:
3633:
3631:
3625:
3624:
3621:
3620:
3618:
3617:
3615:Alfvén surface
3612:
3607:
3602:
3597:
3592:
3587:
3582:
3577:
3571:
3569:
3563:
3562:
3560:
3559:
3554:
3549:
3543:
3541:
3535:
3534:
3532:
3531:
3526:
3521:
3516:
3511:
3505:
3503:
3494:
3488:
3487:
3485:
3484:
3479:
3474:
3472:Radiation zone
3469:
3463:
3461:
3455:
3454:
3452:
3451:
3445:
3442:
3441:
3436:
3434:
3433:
3426:
3419:
3411:
3405:
3404:
3385:
3384:
3383:
3382:
3381:
3378:
3375:
3372:
3325:
3324:
3323:
3278:
3275:
3274:
3273:
3260:
3255:
3250:
3249:
3248:
3243:
3235:
3229:
3224:
3223:
3222:
3210:
3204:
3199:
3187:
3182:
3168:
3167:External links
3165:
3163:
3162:
3124:
3122:
3119:
3116:
3115:
3104:on 29 May 2010
3089:
3038:
2989:
2924:
2871:
2830:
2787:
2746:
2687:
2626:
2599:
2572:(2): 295–307.
2552:
2521:
2491:
2436:
2414:
2408:10.1086/141602
2373:
2358:
2327:
2307:10.1086/306671
2293:(1): 436–450.
2270:
2224:
2198:
2177:(2): 695–710.
2157:
2116:
2045:
2002:
1993:
1952:
1905:
1892:978-0309076425
1891:
1871:
1864:
1838:
1808:
1761:
1748:
1699:
1682:
1671:on 2 July 2011
1665:UNESCO Courier
1652:
1626:
1591:
1552:
1514:
1489:
1464:
1442:
1427:
1426:
1424:
1421:
1419:
1418:
1416:sunspot number
1410:
1405:
1397:
1392:
1390:Solar rotation
1387:
1382:
1377:
1372:
1365:
1359:
1352:
1350:
1347:
1310:Main article:
1307:
1304:
1280:
1277:
1273:
1269:
1266:
1259:
1256:
1236:
1233:
1210:
1207:
1203:
1199:
1196:
1189:
1186:
1158:
1155:
1151:
1147:
1144:
1137:
1118:Little Ice Age
1113:Little Ice Age
1105:global warming
1101:Solar activity
1068:solar activity
1063:
1060:
1044:hydrogen-alpha
1002:Canary Islands
978:Main article:
975:
972:
967:power spectrum
946:
945:
936:
935:
927:
926:
925:
924:
923:
903:Main article:
900:
897:
860:solar activity
852:solar cycle 24
819:Main article:
816:
813:
793:
790:
764:
761:
757:active regions
738:
735:
672:
669:
667:
664:
615:Thomas Harriot
574:star catalogue
543:
540:
505:proper motions
481:active regions
460:
459:
457:
456:
449:
442:
434:
431:
430:
427:
426:
424:Radio emission
421:
416:
411:
410:
409:
399:
394:
389:
388:
387:
382:
371:
366:
365:
362:
361:
358:
357:
352:
347:
346:
345:
340:
335:
330:
325:
320:
313:Magnetic storm
310:
305:
300:
295:
290:
285:
280:
274:
269:
268:
265:
264:
261:
260:
255:
250:
245:
240:
235:
229:
224:
223:
220:
219:
216:
215:
210:
205:
204:
203:
198:
187:
184:
183:
180:
179:
178:
177:
172:
167:
162:
157:
149:
148:
143:
135:
134:
128:
127:
116:
115:
112:
101:
98:solar cycle 24
93:
92:
91:
82:
81:
80:
71:
70:
62:
61:
60:
51:
50:
42:
41:
40:
39:
38:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
4030:
4019:
4016:
4014:
4011:
4010:
4008:
3998:
3988:
3986:
3976:
3974:
3964:
3962:
3957:
3952:
3950:
3940:
3936:
3923:
3915:
3914:
3911:
3905:
3902:
3900:
3897:
3895:
3892:
3891:
3889:
3885:
3881:
3877:
3875:
3871:
3865:
3862:
3860:
3857:
3855:
3852:
3850:
3849:Space weather
3847:
3845:
3844:Space climate
3842:
3840:
3837:
3835:
3832:
3830:
3827:
3825:
3822:
3820:
3819:Solar physics
3817:
3815:
3812:
3810:
3807:
3805:
3802:
3800:
3797:
3795:
3792:
3790:
3787:
3785:
3782:
3780:
3777:
3771:
3768:
3767:
3766:
3763:
3762:
3761:
3758:
3756:
3753:
3749:
3748:Lunar eclipse
3746:
3744:
3741:
3740:
3739:
3736:
3735:
3733:
3729:
3723:
3720:
3718:
3715:
3713:
3710:
3708:
3705:
3703:
3702:Current sheet
3700:
3699:
3697:
3695:
3691:
3685:
3682:
3680:
3677:
3675:
3672:
3670:
3667:
3665:
3662:
3660:
3659:Solar minimum
3657:
3655:
3654:Solar maximum
3652:
3650:
3649:Active region
3647:
3643:
3640:
3639:
3638:
3635:
3634:
3632:
3630:
3626:
3616:
3613:
3611:
3608:
3606:
3603:
3601:
3598:
3596:
3593:
3591:
3588:
3586:
3583:
3581:
3578:
3576:
3573:
3572:
3570:
3568:
3564:
3558:
3555:
3553:
3550:
3548:
3545:
3544:
3542:
3540:
3536:
3530:
3529:Ellerman bomb
3527:
3525:
3522:
3520:
3517:
3515:
3512:
3510:
3507:
3506:
3504:
3502:
3498:
3495:
3493:
3489:
3483:
3480:
3478:
3475:
3473:
3470:
3468:
3465:
3464:
3462:
3460:
3456:
3450:
3447:
3446:
3443:
3439:
3432:
3427:
3425:
3420:
3418:
3413:
3412:
3409:
3393:
3392:
3386:
3379:
3376:
3373:
3369:
3368:
3358:
3354:
3350:
3349:
3338:
3334:
3330:
3326:
3313:
3309:
3305:
3304:
3293:
3289:
3285:
3281:
3280:
3276:
3271:
3267:
3264:
3261:
3259:
3256:
3254:
3251:
3247:
3244:
3242:
3239:
3238:
3236:
3233:
3230:
3228:
3225:
3221:
3220:Space weather
3217:
3216:
3214:
3211:
3208:
3205:
3203:
3200:
3198:
3194:
3191:
3188:
3186:
3183:
3174:
3171:
3170:
3166:
3159:
3153:
3145:
3141:
3138:(10): 38–41.
3137:
3133:
3132:
3126:
3125:
3120:
3103:
3099:
3093:
3090:
3084:
3079:
3074:
3069:
3065:
3061:
3057:
3053:
3049:
3042:
3039:
3034:
3030:
3026:
3022:
3017:
3012:
3008:
3004:
3000:
2993:
2990:
2985:
2981:
2976:
2971:
2967:
2963:
2959:
2955:
2951:
2947:
2943:
2939:
2935:
2928:
2925:
2920:
2916:
2912:
2908:
2904:
2900:
2895:
2890:
2886:
2882:
2875:
2872:
2866:
2861:
2857:
2853:
2849:
2845:
2841:
2834:
2831:
2826:
2822:
2818:
2814:
2810:
2806:
2802:
2798:
2791:
2788:
2782:
2777:
2773:
2769:
2765:
2761:
2757:
2750:
2747:
2742:
2738:
2734:
2730:
2725:
2720:
2715:
2710:
2706:
2702:
2698:
2691:
2688:
2685:
2681:
2678:
2673:
2669:
2665:
2661:
2657:
2653:
2649:
2645:
2641:
2637:
2630:
2627:
2614:
2610:
2603:
2600:
2595:
2591:
2587:
2583:
2579:
2575:
2571:
2567:
2566:Solar Physics
2563:
2556:
2553:
2540:
2536:
2532:
2525:
2522:
2509:
2505:
2501:
2495:
2492:
2487:
2483:
2479:
2475:
2471:
2467:
2463:
2459:
2455:
2451:
2447:
2440:
2437:
2424:
2418:
2415:
2409:
2404:
2400:
2396:
2392:
2388:
2384:
2377:
2374:
2369:
2362:
2359:
2346:
2342:
2338:
2331:
2328:
2316:
2312:
2308:
2304:
2300:
2296:
2292:
2288:
2281:
2274:
2271:
2266:
2262:
2258:
2254:
2250:
2246:
2242:
2238:
2231:
2229:
2225:
2212:
2208:
2202:
2199:
2193:
2188:
2184:
2180:
2176:
2172:
2168:
2161:
2158:
2152:
2147:
2143:
2139:
2135:
2131:
2127:
2120:
2117:
2105:
2101:
2097:
2093:
2089:
2085:
2080:
2075:
2071:
2067:
2060:
2052:
2050:
2046:
2041:
2037:
2033:
2029:
2025:
2021:
2017:
2013:
2006:
2003:
1997:
1994:
1989:
1985:
1980:
1975:
1971:
1967:
1963:
1956:
1953:
1948:
1944:
1940:
1936:
1932:
1928:
1924:
1920:
1919:Solar Physics
1916:
1909:
1906:
1894:
1888:
1884:
1883:
1875:
1872:
1867:
1861:
1857:
1853:
1849:
1842:
1839:
1826:
1822:
1818:
1812:
1809:
1804:
1800:
1796:
1792:
1788:
1784:
1780:
1776:
1775:Solar Physics
1772:
1765:
1762:
1758:
1752:
1749:
1744:
1740:
1735:
1730:
1726:
1722:
1718:
1714:
1710:
1703:
1700:
1696:
1692:
1686:
1683:
1670:
1666:
1662:
1656:
1653:
1640:
1636:
1630:
1627:
1622:
1618:
1614:
1610:
1606:
1602:
1595:
1592:
1588:
1576:
1572:
1568:
1561:
1559:
1557:
1553:
1541:
1537:
1533:
1529:
1525:
1518:
1515:
1502:
1496:
1494:
1490:
1477:
1471:
1469:
1465:
1452:
1446:
1443:
1438:
1432:
1429:
1422:
1414:
1411:
1409:
1406:
1401:
1398:
1396:
1395:Space weather
1393:
1391:
1388:
1386:
1383:
1381:
1378:
1376:
1373:
1371:
1370:
1366:
1363:
1360:
1357:
1354:
1353:
1348:
1346:
1344:
1340:
1335:
1331:
1327:
1323:
1319:
1313:
1305:
1303:
1301:
1295:
1278:
1275:
1267:
1257:
1254:
1234:
1231:
1208:
1205:
1197:
1187:
1184:
1175:
1156:
1153:
1145:
1135:
1127:
1121:
1119:
1114:
1110:
1106:
1102:
1098:
1096:
1092:
1088:
1084:
1081:
1077:
1073:
1072:space weather
1069:
1061:
1059:
1057:
1053:
1049:
1045:
1041:
1037:
1033:
1029:
1025:
1020:
1018:
1014:
1013:spectroscopes
1010:
1003:
999:
995:
991:
986:
981:
973:
968:
963:
954:
950:
940:
931:
922:
919:
914:
912:
906:
898:
896:
894:
893:Babcock Model
890:
886:
881:
877:
874:
870:
868:
863:
861:
853:
832:
827:
822:
814:
812:
810:
806:
802:
798:
791:
789:
785:
783:
778:
774:
771:in the Sun's
770:
762:
760:
758:
736:
734:
732:
731:Wilson effect
727:
725:
721:
715:
713:
709:
705:
700:
698:
694:
690:
686:
677:
670:
665:
663:
660:
656:
652:
648:
647:Royal Society
643:
638:
636:
632:
628:
624:
620:
616:
611:
609:
605:
600:
598:
594:
591:, student of
590:
586:
585:ancient Greek
582:
577:
575:
571:
566:
562:
558:
557:
549:
541:
539:
537:
533:
529:
525:
522:events. Most
521:
517:
513:
512:coronal loops
508:
506:
502:
498:
492:
490:
486:
482:
478:
475:that inhibit
474:
473:magnetic flux
470:
469:Sun's surface
466:
455:
450:
448:
443:
441:
436:
435:
433:
432:
425:
422:
420:
417:
415:
412:
408:
405:
404:
403:
400:
398:
395:
393:
390:
386:
383:
381:
378:
377:
376:
373:
372:
369:
364:
363:
356:
353:
351:
348:
344:
341:
339:
338:Space tornado
336:
334:
331:
329:
326:
324:
321:
319:
316:
315:
314:
311:
309:
306:
304:
301:
299:
296:
294:
291:
289:
288:Magnetosheath
286:
284:
281:
279:
276:
275:
272:
267:
266:
259:
256:
254:
251:
249:
246:
244:
241:
239:
238:Parker spiral
236:
234:
231:
230:
227:
222:
221:
214:
211:
209:
206:
202:
199:
197:
194:
193:
192:
189:
188:
182:
181:
176:
175:Space weather
173:
171:
170:Space climate
168:
166:
163:
161:
158:
156:
153:
152:
151:
150:
146:
141:
137:
136:
133:
129:
125:
124:
113:
110:
106:
102:
99:
95:
94:
86:
75:
66:
55:
46:
37:
33:
19:
3997:Solar System
3829:Solar System
3799:Solar energy
3794:Solar dynamo
3755:Heliophysics
3585:Coronal loop
3580:Coronal hole
3557:Moreton wave
3539:Chromosphere
3523:
3396:. Retrieved
3390:
3360:. Retrieved
3356:
3341:. Retrieved
3337:the original
3332:
3315:. Retrieved
3311:
3296:. Retrieved
3292:the original
3287:
3277:Sunspot data
3152:cite journal
3135:
3129:
3106:. Retrieved
3102:the original
3092:
3055:
3051:
3041:
3006:
3002:
2992:
2941:
2937:
2927:
2884:
2880:
2874:
2847:
2843:
2833:
2800:
2796:
2790:
2763:
2760:Scholarpedia
2759:
2749:
2704:
2700:
2690:
2639:
2635:
2629:
2617:. Retrieved
2613:the original
2607:Stu Turner.
2602:
2569:
2565:
2555:
2543:. Retrieved
2539:the original
2524:
2512:. Retrieved
2508:the original
2503:
2494:
2453:
2449:
2439:
2429:27 September
2427:. Retrieved
2417:
2390:
2386:
2376:
2367:
2361:
2349:. Retrieved
2345:the original
2340:
2330:
2318:. Retrieved
2290:
2286:
2273:
2240:
2236:
2215:. Retrieved
2211:the original
2201:
2174:
2170:
2160:
2133:
2129:
2119:
2107:. Retrieved
2069:
2065:
2015:
2011:
2005:
1996:
1969:
1965:
1955:
1922:
1918:
1908:
1896:. Retrieved
1881:
1874:
1847:
1841:
1829:. Retrieved
1825:the original
1820:
1811:
1778:
1774:
1764:
1756:
1751:
1716:
1712:
1702:
1694:
1685:
1673:. Retrieved
1669:the original
1664:
1655:
1643:. Retrieved
1638:
1629:
1604:
1600:
1594:
1586:
1579:. Retrieved
1575:the original
1543:. Retrieved
1531:
1527:
1517:
1505:. Retrieved
1480:. Retrieved
1455:. Retrieved
1445:
1431:
1403:(predictive)
1400:Spörer's law
1367:
1343:XX Trianguli
1330:spectroscopy
1315:
1296:
1122:
1099:
1065:
1036:filter glass
1028:human vision
1021:
1006:
915:
911:solar maxima
908:
878:
871:
867:Spörer's law
864:
856:
831:Spörer's law
795:
786:
766:
754:
728:
720:Gas pressure
716:
706:of a heated
701:
682:
657:in 1865 and
639:
621:astronomers
612:
601:
589:Theophrastus
578:
564:
560:
554:
552:
524:solar flares
520:reconnection
509:
493:
464:
463:
397:Coronal hole
303:Ring current
293:Plasmasphere
185:Fundamentals
165:Solar System
132:Heliophysics
111:observatory.
36:
3985:Outer space
3973:Spaceflight
3887:Exploration
3765:Solar deity
3712:Heliosheath
3694:Heliosphere
3664:Wolf number
3637:Solar cycle
3501:Photosphere
3083:2433/153022
2766:(3): 3967.
2217:22 February
1972:: 265–318.
1581:20 February
1507:22 February
1482:22 February
1457:22 February
1413:Wolf number
1385:Solar cycle
1341: star
1062:Application
1052:attenuation
821:Solar cycle
815:Solar cycle
697:photosphere
516:prominences
489:solar cycle
414:Solar flare
392:Solar storm
375:Solar cycle
155:Heliosphere
4007:Categories
3839:Solar time
3760:In culture
3717:Heliopause
3669:Solar wind
3600:Prominence
3492:Atmosphere
3477:Tachocline
3108:14 January
3016:2212.09788
2894:1606.05258
2714:1708.04904
2207:"Sunspots"
2079:1611.04803
1607:(4): 406.
1451:"Sunspots"
1423:References
1356:Hale's law
1326:photometry
1322:red dwarfs
1080:short-wave
1076:ionosphere
951:, showing
777:convection
708:black body
671:Morphology
572:(甘德) in a
477:convection
350:Polar wind
248:Cosmic ray
243:Solar wind
3949:Astronomy
3722:Bow shock
3629:Variation
3595:Nanoflare
3371:included.
3144:0033-4812
2966:1364-5021
2733:2115-7251
2619:5 January
2594:1573-093X
2320:5 January
2315:121691780
2265:120721248
2109:5 January
2104:119419693
1988:122986696
1947:126329839
1803:216259048
1743:1366-8781
1697:, 11.4–5.
1362:Joy's law
1318:starspots
1276:−
1268:⋅
1255:±
1235:σ
1206:−
1198:⋅
1185:±
1154:−
1146:⋅
1024:naked eye
763:Formation
737:Lifecycle
704:luminance
597:Aristotle
536:starspots
497:telescope
196:Flux tube
4018:Vortices
3922:Category
3398:13 March
3343:11 March
3317:11 March
3298:11 March
3266:Archived
3193:Archived
2984:32831591
2919:55902879
2825:17776650
2741:37433045
2680:Archived
2677:PDF Copy
2672:33896851
2664:17771739
2545:14 April
2514:10 March
2478:15510145
1831:19 March
1408:Starspot
1349:See also
1312:Starspot
1306:Starspot
1040:eyepiece
998:La Palma
833:behavior
689:penumbra
623:Johannes
587:scholar
465:Sunspots
333:Substorm
18:Sun spot
3935:Portals
3738:Eclipse
3731:Related
3552:Spicule
3524:Sunspot
3519:Faculae
3514:Granule
3438:The Sun
3362:21 June
3060:Bibcode
3021:Bibcode
2975:7428030
2946:Bibcode
2899:Bibcode
2887:: A30.
2852:Bibcode
2850:: A14.
2805:Bibcode
2797:Science
2768:Bibcode
2707:: A25.
2644:Bibcode
2636:Science
2574:Bibcode
2486:4373732
2458:Bibcode
2395:Bibcode
2393:: 315.
2351:9 March
2295:Bibcode
2245:Bibcode
2179:Bibcode
2138:Bibcode
2084:Bibcode
2072:: A59.
2040:1654166
2020:Bibcode
1927:Bibcode
1898:19 June
1783:Bibcode
1721:Bibcode
1675:14 July
1645:14 July
1609:Bibcode
1545:27 June
1536:Bibcode
1224:with a
1174:faculae
1032:filters
1000:in the
953:Maunder
887:field.
666:Physics
619:Frisian
556:I Ching
542:History
278:History
3567:Corona
3142:
2982:
2972:
2964:
2917:
2823:
2739:
2731:
2670:
2662:
2592:
2484:
2476:
2450:Nature
2313:
2263:
2136:: L1.
2102:
2038:
1986:
1945:
1889:
1862:
1801:
1741:
1641:. 2007
1534:: 59.
1478:. NASA
1453:. NOAA
1261:
1191:
1139:
1050:glass
885:dipole
809:vortex
693:normal
570:Gan De
518:, and
318:Aurora
191:Plasma
3961:Stars
3679:Flare
3547:Plage
3011:arXiv
2915:S2CID
2889:arXiv
2737:S2CID
2709:arXiv
2668:S2CID
2482:S2CID
2311:S2CID
2283:(PDF)
2261:S2CID
2100:S2CID
2074:arXiv
2062:(PDF)
2036:S2CID
1984:S2CID
1943:S2CID
1799:S2CID
1501:"Sun"
792:Decay
685:umbra
593:Plato
532:stars
503:, or
109:TRACE
3859:Star
3770:List
3467:Core
3449:List
3400:2015
3364:2010
3345:2005
3319:2005
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