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While Observing the Sun, You Note a Large Number of Sunspots. What Can You Conclude?

Written By Sunday, February 13, 2022 Add Comment Edit

Temporary phenomena on the Sun'south photosphere

Sunspots
NASA's SDO Observes Largest Sunspot of the Solar Cycle (15430820129).jpgSunspots 1302 Sep 2022 by NASA.jpg
172197main NASA Flare Gband lg-withouttext.jpgSunspot TRACE.jpeg
Solar Archipelago - Flickr - NASA Goddard Photo and Video.jpg
  • Meridian: active region 2192 in 2022 containing the largest sunspot of solar bike 24[ane] and active region 1302 in September 2011.
  • Middle: sunspot close-upwards in the visible spectrum (left) and another sunspot in UV, taken by the TRACE observatory.
  • Bottom: a big group of sunspots stretching virtually 320,000 km (200,000 mi) across.

Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused past concentrations of magnetic flux that inhibit convection. Sunspots appear within active regions, usually in pairs of opposite magnetic polarity.[2] Their number varies according to the approximately eleven-year solar cycle.

Individual sunspots or groups of sunspots may concluding anywhere from a few days to a few months, but somewhen decay. Sunspots expand and contract as they move across the surface of the Dominicus, with diameters ranging from xvi km (x mi)[3] to 160,000 km (100,000 mi).[4] Larger sunspots tin can be visible from Earth without the aid of a telescope.[5] They may travel at relative speeds, or proper motions, of a few hundred meters per second when they outset emerge.

Indicating intense magnetic activity, sunspots back-trail other active region phenomena such every bit coronal loops, prominences, and reconnection events. Virtually solar flares and coronal mass ejections originate in these magnetically active regions effectually visible sunspot groupings. Similar phenomena indirectly observed on stars other than the Sun are ordinarily called starspots, and both lite and night spots have been measured.[6]

History [edit]

The earliest record of sunspots is constitute in the Chinese I Ching, completed before 800 BC.[7] The text describes that a dou and mei were observed in the sun, where both words refer to a small obscuration.[vii] The primeval record of a deliberate sunspot observation also comes from Mainland china, and dates to 364 BC, based on comments by astronomer Gan De (甘德) in a star catalogue.[8] By 28 BC, Chinese astronomers were regularly recording sunspot observations in official imperial records.[9]

The get-go articulate mention of a sunspot in Western literature is circa 300 BC, by ancient Greek scholar Theophrastus, student of Plato and Aristotle and successor to the latter.[10]

The start drawings of sunspots were fabricated by English language monk John of Worcester in December 1128.[11] [12]

Sunspots were get-go observed telescopically in late 1610 by English astronomer Thomas Harriot and Western frisian astronomers Johannes and David Fabricius, who published a description in June 1611.[13] After Johannes Fabricius' death at the age of 29, the volume remained obscure and was eclipsed past the independent discoveries of and publications about sunspots by Christoph Scheiner and Galileo Galilei, few months later.[14]

In the early 19th Century, William Herschel was ane of the first to equate sunspots with the abundance of heating and cooling it was capable of causing on Earth. He believed that the "great shallows (sunspots' penumbrae) ridges (brilliant, elevated extended features resembling faculae) nodules (bright, elevated, withal smaller features resembling luculi) and corrugations (less luminous, crude, mottled, dark features) instead of small indentations (depressed, extended nighttime features) on the sun would let in large amounts of estrus into Globe. On the other hand, "pores, small indentations -key regions of nighttime, depressed spots - and the nodules' and ridges' absence," meant less heat touching Earth.[fifteen] During his recognition of solar behavior and hypothesized solar construction, he inadvertently picked up the relative absence birthday of spots on the Sun from July, 1795 to January, 1800. He was perhaps the very outset to construct a past record or observed or missing sunspots and found that, in England at to the lowest degree, the absence of sunspots coincided with high wheat prices. Herschel read his paper before the Royal Society. He was completely misinterpreted and heartily ridiculed earlier that torso.[16]

Physics [edit]

Morphology [edit]

A decaying sunspot shown over the course of two hours. The umbra is separated into 2 pieces inside the penumbra by a lightbridge.[17] Solar pores are also visible to the left of the penumbra.

Sunspots have two primary structures: a central umbra and a surrounding penumbra. The umbra is the darkest region of a sunspot and is where the magnetic field is strongest and approximately vertical, or normal, to the Sun's surface, or photosphere. The umbra may be surrounded completely or just partially by a brighter region known every bit the penumbra.[18] The penumbra is equanimous of radially elongated structures known every bit penumbral filaments and has a more inclined magnetic field than the umbra.[xix] Within sunspot groups, multiple umbrae may be surrounded by a single, continuous penumbra.

The temperature of the umbra is roughly 3,000–4,500 K (2,700–iv,200 °C), in contrast to the penumbra at about 5,780 K (5,500 °C) leaving sunspots clearly visible equally nighttime spots. This is considering the luminance of a heated black body (closely approximated by the photosphere) at these temperatures varies greatly with temperature. Isolated from the surrounding photosphere, a single sunspot would polish brighter than the full moon, with a crimson-orange color.[twenty]

The Wilson effect implies that sunspots are depressions on the Dominicus's surface.

Lifecycle [edit]

The emergence and evolution of a sunspot grouping over a flow of ii weeks.

The appearance of an private sunspot may final anywhere from a few days to a few months, though groups of sunspots and their associated agile regions tend to last weeks or months. Sunspots expand and contract every bit they move across the surface of the Sunday, with diameters ranging from 16 km (ten mi) to 160,000 km (100,000 mi).[ citation needed ]

Germination [edit]

Although the details of sunspot formation are all the same a matter of ongoing research, it is widely understood that they are the visible manifestations of magnetic flux tubes in the Sun's convective zone projecting through the photosphere within active regions.[21] Their characteristic darkening occurs due to this strong magnetic field inhibiting convection in the photosphere. Every bit a result, the free energy flux from the Sun's interior decreases, and with it, surface temperature, causing the surface surface area through which the magnetic field passes to look night against the bright background of photospheric granules.

Sunspots initially appear in the photosphere as small darkened spots lacking a penumbra. These structures are known as solar pores.[22] Over fourth dimension, these pores increment in size and move towards i another. When a pore gets large enough, typically around iii,500 km (two,000 mi) in diameter, a penumbra volition begin to grade.[21]

Decay [edit]

Magnetic pressure should tend to remove field concentrations, causing the sunspots to disperse, just sunspot lifetimes are measured in days to weeks. In 2001, observations from the Solar and Heliospheric Observatory (SOHO) using audio waves traveling below the photosphere (local helioseismology) were used to develop a three-dimensional image of the internal structure below sunspots; these observations show that a powerful downdraft underneath each sunspot, forms a rotating vortex that sustains the concentrated magnetic field.[23]

Solar bike [edit]

Point chart showing sunspot area as percent of the total area at various latitudes, above grouped bar chart showing average daily sunspot area as % of visible hemisphere.

The full solar disk over the course of 13 days during the rise of solar bicycle 24.

Solar bicycle duration is typically almost eleven years, varying from just under 10 to but over 12 years. Over the solar cycle, sunspot populations rise apace and so autumn more slowly. The bespeak of highest sunspot activeness during a cycle is known as solar maximum, and the point of lowest activeness as solar minimum. This menstruation is besides observed in most other solar action and is linked to a variation in the solar magnetic field that changes polarity with this menstruation.

Early on in the cycle, sunspots appear at higher latitudes and so move towards the equator equally the wheel approaches maximum, following Spörer's police force. Spots from ii sequential cycles co-exist for several years during the years well-nigh solar minimum. Spots from sequential cycles tin can exist distinguished past direction of their magnetic field and their latitude.

The Wolf number sunspot alphabetize counts the boilerplate number of sunspots and groups of sunspots during specific intervals. The 11-twelvemonth solar cycles are numbered sequentially, starting with the observations made in the 1750s.[24]

George Ellery Hale first linked magnetic fields and sunspots in 1908.[25] Hale suggested that the sunspot cycle menstruum is 22 years, covering ii periods of increased and decreased sunspot numbers, accompanied by polar reversals of the solar magnetic dipole field. Horace W. Babcock later proposed a qualitative model for the dynamics of the solar outer layers. The Babcock Model explains that magnetic fields cause the behavior described by Spörer'due south law, as well as other effects, which are twisted by the Dominicus's rotation.

Longer-period trends [edit]

Sunspot numbers also change over long periods. For example during the period known as the modern maximum from 1900 to 1958 the solar maxima trend of sunspot count was upwards; for the following sixty years the trend was mostly downwards.[26] Overall, the Sun was final as active as the modern maximum over 8,000 years ago.[27]

Sunspot number is correlated with the intensity of solar radiation over the flow since 1979, when satellite measurements became available. The variation acquired past the sunspot cycle to solar output is on the order of 0.1% of the solar constant (a superlative-to-trough range of one.3 W·m−2 compared with 1366 West·m−2 for the average solar abiding).[28] [29]

400-year history of sunspot numbers, showing Maunder and Dalton minima, and the Mod Maximum (left) and 11,000-twelvemonth sunspot reconstruction showing a downwardly trend over 2000 BC – 1600 AD followed past the recent 400 yr uptrend

Modern observation [edit]

Photo of six-story building with fenced balcony containing large telescope

Sunspots are observed with state-based and World-orbiting solar telescopes. These telescopes use filtration and projection techniques for straight observation, in addition to various types of filtered cameras. Specialized tools such as spectroscopes and spectrohelioscopes are used to examine sunspots and sunspot areas. Artificial eclipses permit viewing of the circumference of the Lord's day every bit sunspots rotate through the horizon.

Since looking directly at the Sun with the naked eye permanently damages human vision, apprentice observation of sunspots is generally conducted using projected images, or direct through protective filters. Pocket-sized sections of very night filter glass, such as a #14 welder's glass, are effective. A telescope eyepiece can projection the image, without filtration, onto a white screen where information technology can exist viewed indirectly, and even traced, to follow sunspot evolution. Special purpose hydrogen-alpha narrow bandpass filters and aluminum-coated glass attenuation filters (which accept the appearance of mirrors due to their extremely high optical density) on the forepart of a telescope provide safe observation through the eyepiece.

Awarding [edit]

Due to its link to other kinds of solar action, sunspot occurrence can be used to help predict space weather, the state of the ionosphere, and hence the weather of brusque-wave radio propagation or satellite communications. High sunspot activity is celebrated by members of the amateur radio customs as a harbinger of excellent ionospheric propagation conditions that greatly increase radio range in the HF bands. During sunspot peaks, worldwide radio advice tin be possible on frequencies as high as the half dozen-meter VHF ring.[30] Solar activity (and the solar cycle) have been implicated in global warming, originally the part of the Maunder Minimum of sunspot occurrence in the Lilliputian Water ice Age in European winter climate.[31] Sunspots themselves, in terms of the magnitude of their radiant-energy arrears, have a weak effect on solar flux[32] however the total solar flux increases as "At solar maximum the Sun is some 0.1% brighter than its solar-minimum level". On longer time scales, such as the solar bike, other magnetic phenomena (faculae and the chromospheric network) correlate with sunspot occurrence.[33]

Starspot [edit]

In 1947, G. E. Kron proposed that starspots were the reason for periodic changes in brightness on red dwarfs.[6] Since the mid-1990s, starspot observations accept been made using increasingly powerful techniques yielding more and more than particular: photometry showed starspot growth and disuse and showed cyclic beliefs similar to the Sun's; spectroscopy examined the construction of starspot regions past analyzing variations in spectral line splitting due to the Zeeman effect; Doppler imaging showed differential rotation of spots for several stars and distributions different from the Sunday'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 behemothic K0 star XX Triangulum (Hard disk drive 12545) with a temperature of 3,500 K (3,230 °C), together with a warm spot of 4,800 Thou (4,530 °C).[6] [34]

See also [edit]

  • Messages on Sunspots
  • Joy'southward law
  • List of solar cycles
  • Radio propagation
  • Solar cycle
  • Solar rotation
  • Space weather condition
  • Spörer's police (predictive)
  • Starspot
  • Wolf number sunspot number

References [edit]

  1. ^ "Gentle giant sunspot region 2192".
  2. ^ "Sunspots". NOAA. Retrieved 22 February 2013.
  3. ^ "How Are Magnetic Fields Related To Sunspots?". NASA. Retrieved 22 February 2013.
  4. ^ "Sun". HowStuffWorks. 22 April 2009. Retrieved 22 February 2013.
  5. ^ "1989QJRAS..30...59M Page 60". articles.adsabs.harvard.edu. Bibcode:1989QJRAS..xxx...59M. Retrieved 27 June 2021.
  6. ^ a b c Strassmeier, M. Thou. (10 June 1999). "Smallest KPNO Telescope Discovers Biggest Starspots (printing release 990610)". University of Vienna. Archived from the original on 24 June 2010. Retrieved xx February 2008. starspots vary on the same (curt) time scales equally Sunspots practice ... Hard disk drive 12545 had a warm spot (350 K in a higher place photospheric temperature; the white area in the picture)
  7. ^ a b Xu Zhen-Tao (1980). "The hexagram "Feng" in "the book of changes" as the primeval written tape of sunspot". Chinese Astronomy. four (4): 406. Bibcode:1980ChA.....4..406X. doi:10.1016/0146-6364(80)90034-1.
  8. ^ "Early Astronomy and the Beginnings of a Mathematical Science". NRICH (University of Cambridge). 2007. Retrieved xiv July 2010.
  9. ^ "The Observation of Sunspots". UNESCO Courier. 1988. Archived from the original on 2 July 2011. Retrieved 14 July 2010.
  10. ^ "Letter of the alphabet to the Editor: Sunspot observations past Theophrastus revisited"
  11. ^ Stephenson, F. R.; Willis, D. Grand. (1999). "The primeval drawing of sunspots". Astronomy & Geophysics. forty (6): vi.21–6.22. Bibcode:1999A&Thou....40f..21S. doi:ten.1093/astrog/40.vi.vi.21. ISSN 1366-8781.
  12. ^ Stefan Hughes, Catchers of the Light: The Forgotten Lives of the Men and Women Who Outset Photographed the Heavens, ArtDeCiel Publishing, 2022 p.317
  13. ^ "Keen Moments in the History of Solar Physics i". Neat Moments in the History of Solar Physics. Archived from the original on 1 March 2006. Retrieved nineteen March 2006.
  14. ^ Carlowicz, Michael J.; López, Ramón (2002). Storms from the Lord's day: The Emerging Science of Space Weather. Joseph Henry Press. p. 66. ISBN9780309076425 . Retrieved xix June 2020.
  15. ^ Herschel, Westward., "Observations tending to investigate the nature of the Dominicus, in club to find causes and symptoms of its variable emission of lite and oestrus"...Philosophical Transactions of the Regal Social club of London, Vol. 91, 1801
  16. ^ Soon, Westward., and Yaskell, S.H., The Maunder Minimum and the Variable Lord's day-earth Connectedness (Earth Scientific Press: 2003) pp 87-88
  17. ^ Felipe, T.; Collados, M.; Khomenko, E.; Kuckein, C.; Asensio Ramos, A.; Balthasar, H.; Berkefeld, T.; Denker, C.; Feller, A.; Franz, Chiliad.; 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, M.; Sobotka, Chiliad.; Solanki, S. K.; Soltau, D.; Staude, J.; Strassmeier, Grand. G.; Volkmer, R.; von der Lühe, O.; Waldmann, T. (December 2016). "Three-dimensional structure of a sunspot light bridge" (PDF). Astronomy & Astrophysics. 596: A59. doi:10.1051/0004-6361/201629586. Retrieved 5 January 2022.
  18. ^ Schlichenmaier, R.; Rezaei, R.; Bello González, N.; Waldmann, T. A. (March 2010). "The formation of a sunspot penumbra". Astronomy and Astrophysics. 512: L1. doi:ten.1051/0004-6361/201014112.
  19. ^ Mathew, S. K.; Lagg, A.; Solanki, South. K.; Collados, M.; Borrero, J. K.; Berdyugina, South.; Krupp, North.; Woch, J.; Frutiger, C. (November 2003). "3 dimensional structure of a regular sunspot from the inversion of IR Stokes profiles". Astronomy & Astrophysics. 410 (two): 695–710. doi:10.1051/0004-6361:20031282.
  20. ^ "Sunspots". NASA. 1 April 1998. Retrieved 22 Feb 2013.
  21. ^ a b Solanki, Sami G. (1 April 2003). "Sunspots: An overview". Astronomy and Astrophysics Review. 11 (two–3): 153–286. doi:10.1007/s00159-003-0018-4.
  22. ^ Sobotka, Michal; Vazquez, Manuel; Bonet, Jose Antonio; Hanslmeier, Arnold; Hirzberger, Johann (20 January 1999). "Temporal Development of Fine Structures in and around Solar Pores" (PDF). The Astrophysical Journal. 511 (ane): 436–450. doi:10.1086/306671. Retrieved 5 January 2022.
  23. ^ NASA News Release (6 Nov 2001). "SOHO reveals how sunspots accept stranglehold on the Sun". SpaceFlight At present. Archived from the original on 17 January 2015. Retrieved nine March 2013.
  24. ^ Tribble, A. (2003). The Space Environment, Implications for Spacecraft Design. Princeton Academy Press. pp. 15–18.
  25. ^ Hale, 1000. Eastward. (1908). "On the Likely Existence of a Magnetic Field in Sun-Spots". The Astrophysical Journal. 28: 315. Bibcode:1908ApJ....28..315H. doi:10.1086/141602.
  26. ^ "Sunspot index graphics". Solar Influences Information Analysis Center. Retrieved 27 September 2007.
  27. ^ Solanki SK; Usoskin IG; Kromer B; Schüssler M; et al. (October 2004). "Unusual activity of the Sunday during recent decades compared to the previous 11,000 years". Nature. 431 (7012): 1084–1087. Bibcode:2004Natur.431.1084S. doi:x.1038/nature02995. PMID 15510145. S2CID 4373732.
  28. ^ "Solar Forcing of Climate". Climate Modify 2001: Working Group I: The Scientific Basis. Archived from the original on xv March 2005. Retrieved 10 March 2005.
  29. ^ Weart, Spencer (2006). Weart, Spencer (ed.). "The Discovery of Global Warming—Irresolute Lord's day, Irresolute Climate?". American Constitute of Physics. Retrieved xiv April 2007.
  30. ^ Stu Turner. "Sunspots and Propagation". Ham Radio School.com. Archived from the original on 26 June 2017. Retrieved v January 2020.
  31. ^ Boil J.A. (June 1976). "The Maunder Minimum". Science. 192 (4245): 1189–1202. Bibcode:1976Sci...192.1189E. doi:10.1126/science.192.4245.1189. PMID 17771739. S2CID 33896851. PDF Copy Archived 16 February 2010 at the Wayback Machine
  32. ^ Hudson H (2008). "Solar activity". Scholarpedia. 3 (3): 3967. Bibcode:2008SchpJ...3.3967H. doi:x.4249/scholarpedia.3967. Retrieved 27 Jan 2011.
  33. ^ Willson, R. C.; Gulkis, Southward.; Janssen, M.; Hudson, H. S.; Chapman, G. A. (1981). "Observations of solar irradiance variability". Science. 211 (4483): 700–2. Bibcode:1981Sci...211..700W. doi:10.1126/science.211.4483.700. PMID 17776650.
  34. ^ "Derived images showing rotation of cool and warm starspots". Leibniz Plant for Astrophysics. Archived from the original on 29 May 2010. Retrieved 14 Jan 2013.

Further reading [edit]

  • Carl Luetzelschwab, K9LA (October 2016). "The new sunspot numbers". QST. 100 (ten): 38–41. ISSN 0033-4812.

External links [edit]

  • Sunspot Database based on Terrestrial (GPR/DPD) and Satellite (SOHO/SDO) observations from 1872 to Present with the newest data. (Solar Observatory - Debrecen, Hungary)
  • Solar Cycle 24 and VHF Aurora Website (world wide web.solarcycle24.com)
  • Belgium Globe Data Center for the sunspot alphabetize
  • High resolution sunspot image
  • Sunspot images in high-res Impressive collection of sunspot images
  • NOAA Solar Cycle Progression: Current solar cycle.
    • Current conditions: Infinite weather
  • Lockheed Martin Solar and Astrophysics Lab
  • Sunday|trek website An educational resources for teachers and students well-nigh the Sun and its outcome on the Earth
  • Tools to display the current sunspot number in a browser
    • Propfire – displays current sunspot number in browser status bar
    • HamLinks Toolbar – displays solar flux, A Alphabetize and K Index data in a toolbar
  • The Sharpest View of the Lord's day
  • Daily Sunspot Update and Picture of the Sunday (world wide web.spaceweather.com)
  • Animated caption of Sunspots in the Photosphere Archived 16 November 2022 at the Wayback Machine (University of South Wales)

Sunspot data [edit]

  • "eleven,000 Twelvemonth Sunspot Number Reconstruction". Global Change Main Directory. Archived from the original on ii November 2015. Retrieved 11 March 2005.
    • "Unusual activity of the Lord's day during contempo decades compared with the previous eleven,000 years". WDC for Paleoclimatology . Retrieved xi March 2005.
  • "Sunspot Numbers from Ancient Times to Present from NOAA/NGDC". Global Change Primary Directory. Archived from the original on 14 September 2015. Retrieved 11 March 2005.
    • "SUNSPOT NUMBERS". NOAA NGDC Solar Information Services . Retrieved 21 June 2010. [ permanent dead link ]
      • International Sunspot Number—sunspot maximum and minimum 1610–nowadays; almanac numbers 1700–nowadays; monthly numbers 1749–present; daily values 1818–present; and sunspot numbers by north and southward hemisphere. The McNish–Lincoln sunspot prediction is also included.
      • American sunspot numbers 1945–present
      • Ancient sunspot data 165 BC to 1684 AD
      • Grouping Sunspot Numbers (Doug Hoyt re-evaluation) 1610–1995
  • Wilson, Robert M. (Apr 2014). Comparison of the Variations of Sunspot Number, Number of Sunspot Groups, and Sunspot Area, 1875-2013. Huntsville, AL: National Helmsmanship and Space Assistants, Marshall Infinite Flight Center. Retrieved thirteen March 2015.

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Source: https://en.wikipedia.org/wiki/Sunspot

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