# Sun <!-- SOLSIM:BEGIN g31 — Solar System explorer state (hand-built on wt-core, specs/solar/); do not hand-edit inside --> **Microsim — three.js (Wikitube framework):** *The Sun in the Solar System explorer* <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/solar/Solar_System.html?obj=Sun&embed=1" data-title="The Sun in the Solar System explorer"></div> *The Solar System explorer locked on this article's state (`?obj=Sun`); every object and population of the [[PORTAL_Solar_System|Solar System portal]] has its own state in the same scene.* <!-- SOLSIM:END --> <!-- SOLART:BEGIN g31 — Solar System portal child article, wave 1 (SOL-008, pinned oldid 1375342983); do not hand-edit inside --> *Try: switch the scale to true and see how the Sun, about 109 Earth diameters across, still shrinks to a small disc against the width of the planets' orbits, since Earth circles it about 215 solar radii away; set the speed to 1 year/s and watch the planets run around it at very different rates; press l to label them as they pass.* The **Sun** is the star at the centre of the Solar System: a sphere of hot [[Plasma_(physics)|plasma]] 695,700 km in radius, held together by its own [[Gravity|gravity]] and powered by [[Nuclear_fusion|nuclear fusion]] of [[Hydrogen|hydrogen]] into [[Helium|helium]] in its core.[^nasa-sun] It contains about 99.86% of the mass of the Solar System and supplies almost all the energy that reaches [[Earth]], mostly as visible light and infrared radiation.[^woolfson2000][^fu2003] Its light takes about 8.3 minutes to cover the mean distance of 149.6 million km, one [[Astronomical_unit|astronomical unit]] (derived).[^nasa-sun][^iau2012] The Sun formed about 4.6 billion years ago from a collapsing fragment of a molecular cloud and is a G2V main-sequence star, roughly halfway through a hydrogen-burning life of about 10 billion years.[^zirker2002-7][^goldsmith2001] In about 5 billion years it will swell into a red giant, then shed its outer layers and end as a white dwarf.[^schroder2008] The explorer at the top of this page centres on the Sun, with the planets on their orbits around it; its size and distances are drawn on a logarithmic scale by default, so the true-scale option is the one that shows how small the Sun is compared with the system it holds. ## Etymology The English *sun* comes from Old English *sunne*, from Proto-Germanic *\*sunnōn*, with cognates across the Germanic languages; the wider Indo-European family mostly continues a related stem with *l*, as in Latin *sōl* and Greek *hēlios*.[^barnhart1995][^orel2003] From the Latin come *solar* and the planetary scientists' *sol*, a solar day on another planet such as [[Mars]].[^nasa-sol] The astronomical symbol is a circle with a central dot, ☉, used in the units of solar mass M☉, radius R☉ and luminosity L☉.[^allen2000] The study of the Sun is sometimes called heliology.[^collins-heliology] ## General characteristics The Sun is a G-type main-sequence star: spectral class G2, luminosity class V.[^phillips1995-47] Its absolute magnitude of +4.83 makes it brighter than most stars in the [[Milky_Way|Milky Way]], which are dominated by red dwarfs, and it is more massive than about 95% of the stars within 7 parsecs.[^nasa-sun][^robles2008] It is a Population I star, rich in heavy elements, which suggests its birth cloud had been enriched by earlier generations of stars; its formation may have been triggered by shock waves from nearby supernovae.[^zeilik1998][^connelly2012] ### Shape The Sun has no solid surface; its density falls off steeply above the photosphere, the visible layer that defines its radius.[^nasa-sun] Its oblateness, the fractional difference between equatorial and polar radius, is tiny. Measurements from the Solar Dynamics Observatory and the Picard satellite put it near 8 parts per million, smaller than expected from the surface rotation alone, making the Sun the roundest natural object measured.[^gough2012][^meftah2015] ### Rotation The Sun rotates differentially, fastest at the equator: about 25.6 days there and about 33.5 days near the poles, relative to the stars. From the moving Earth the equatorial period appears as about 28 days.[^phillips1995-78] The young Sun spun up to ten times faster and was correspondingly more active; magnetic braking by the outflowing solar wind has slowed it since.[^guinan2009][^pantolmos2017] Helioseismic evidence suggests the core still rotates about once a week, several times faster than the surface.[^fossat2017] ### Composition By mass the photosphere is about 74.9% hydrogen and 23.8% helium; everything heavier, which astronomers call metals, amounts to under 2%, led by [[Oxygen|oxygen]] (about 1%), [[Carbon|carbon]], [[Neon|neon]] and [[Iron|iron]].[^lodders2003][^hansen2004] The photospheric composition, checked against unmelted meteorites, is taken to represent the original Solar System; the protosolar mixture is estimated at about 71.1% hydrogen, 27.4% helium and 1.5% metals.[^lodders2003] In the core, fusion has raised the helium fraction from about 24% to roughly 60%.[^hansen2004-9] ## Structure ### Core The core reaches out to about 20–25% of the solar radius. Standard models put the central temperature at about 15.7 million K and the central density at about 1.6 × 10⁵ kg/m³, some 160 times that of water.[^garcia2007][^nasa-sun] Fusion there runs mainly through the proton–proton chain; about 0.8% of the energy comes from the CNO cycle, a share that will grow as the Sun ages.[^broggini2003][^goupil2011] Almost all the power is produced inside a quarter of the radius.[^phillips1995-47] Each second some 6.2 × 10¹¹ kg of hydrogen becomes helium, and about 4.26 × 10⁹ kg of mass, about 0.7% of the hydrogen fused, is released as energy, giving the luminosity of 3.828 × 10²⁶ W.[^phillips1995-47][^nasa-sun][^shu1982] Because the core is huge, the power per unit volume is small, about 276 W/m³ at the centre in a standard model,[^cohen1998] and fusion regulates itself: a small rise in the rate heats and expands the core, lowering its density and restoring the rate.[^haubold1994] ### Radiative zone From about 0.25 to 0.7 solar radii, energy travels as [[Thermal_radiation|radiation]]. The temperature gradient here is too shallow to drive [[Convection|convection]], and the density falls about a hundredfold across the zone; estimates of the time radiated energy takes to diffuse out range from 10,000 to 170,000 years.[^msfc-interior][^worldbook][^nasa-sunlight] ### Tachocline The thin shear layer between the rigidly rotating radiative zone and the differentially rotating convection zone is the tachocline; it is thought to be where the solar dynamo amplifies the Sun's magnetic field.[^tobias2005][^msfc-interior] ### Convective zone In the outer 30% of the radius the gas is cool and opaque enough that heat is carried by convection: hot plasma rises, cools just below the photosphere and sinks back. The tops of the convection cells show at the surface as granulation and, on larger scales, supergranulation.[^msfc-interior] ### Atmosphere The photosphere, about 500 km thick, is the layer below which the Sun is opaque; its light approximates a [[Black-body_radiation|black body]] at 5,772 K, crossed by absorption lines.[^nasa-sun][^abhyankar1977] Above a temperature minimum near 4,100 K lies the chromosphere, about 2,000 km thick and rising to about 20,000 K; a thin transition region then leads, within a few hundred kilometres, to the corona at one to two million kelvin.[^abhyankar1977][^erdelyi2007] The corona ends at the Alfvén critical surface, beyond which the outflow is faster than magnetic waves can travel back; Parker Solar Probe first crossed it in April 2021, at 16–20 solar radii.[^kasper2021] ### Heliosphere The [[Solar_wind|solar wind]] fills a bubble, the [[Heliosphere|heliosphere]], out to the [[Heliopause|heliopause]], where it meets the [[Interstellar_medium|interstellar medium]]. [[Voyager_1|Voyager 1]] crossed the heliopause on 25 August 2012, about 122 AU from the Sun.[^parker2007][^jpl-voyager] ## Light, radiation, and observation At an apparent magnitude of −26.74, the Sun is by far the brightest object in Earth's sky.[^nasa-sun] At 1 AU it delivers about 1,361–1,368 W/m², the total solar irradiance; the atmosphere reduces this to roughly 1,000 W/m² at the ground with the Sun overhead in clear air.[^pmod2006][^elsharkawi2005] At the top of the atmosphere the energy is about half infrared, 40% visible and 10% ultraviolet.[^fu2003] The luminosity spread over a sphere of radius 1 AU gives 3.828 × 10²⁶ W / (4π × (1.496 × 10¹¹ m)²) ≈ 1,361 W/m² (derived), consistent with the measured value.[^nasa-sun] ### Visible light and observation Seen from space the Sun is white, although its output per unit wavelength peaks in the green.[^stanford-color] Near the horizon, scattering along the long path through the air turns it yellow, orange or red and can dim it enough to look at. Looking at the full Sun heats the retina, and a glance through an unfiltered telescope or binoculars can damage it permanently.[^white1971][^macdonald2012] ### Other radiation Solar ultraviolet light ionises the upper atmosphere into the ionosphere, and most of it is absorbed by the [[Ozone_layer|ozone layer]], so that surface ultraviolet varies strongly with latitude.[^phillips1995-14][^barsh2003] Neutrinos from the core escape almost at once. The detected flux of electron neutrinos was long about a third of the predicted value, the solar neutrino problem, until neutrino oscillation, measured in 2001, showed that the missing two-thirds change flavour on the way.[^schlattl2001] ## Magnetic activity The Sun's magnetic field is 1–2 gauss at the poles but about 3,000 gauss in sunspots and 10–100 gauss in prominences.[^nasa-sun] Its best-known variation is the roughly 11-year sunspot cycle.[^zirker2002-119] The solar wind carries the field outward as the interplanetary magnetic field, and the Sun's rotation winds it into the Parker spiral.[^russell2001] ### Sunspots Sunspots are dark because strong magnetic fields there suppress convection, leaving them cooler than the surrounding photosphere; the largest are tens of thousands of kilometres across.[^gsfc-sunspot] Early in a cycle spots appear at high latitudes and later ones nearer the equator. The 11-year cycle is half of a 22-year magnetic cycle: spot pairs reverse their polarity from one cycle to the next, and the global field flips at each maximum.[^hale1919][^zirker2002-119] ### Solar activity Flares and coronal mass ejections cluster around active regions, while fast solar wind streams from coronal holes; both carry plasma and field into the Solar System, and at Earth they produce auroras and can disrupt radio and power networks.[^zirker2002-120] Between about 1645 and 1715 sunspots almost vanished, the Maunder minimum, a period that overlapped with cold decades of the Little Ice Age in Europe.[^eddy1976][^lean1992] ### Coronal heating Why the corona is hundreds of times hotter than the photosphere below it is still debated. The two leading ideas are heating by waves, especially Alfvén waves, generated by convection, and heating by many small magnetic reconnection events, or nanoflares.[^erdelyi2007] ## Life phases ### Formation The Sun condensed about 4.6 billion years ago from a cloud of mostly hydrogen and helium; the oldest Solar System solids, calcium–aluminium-rich inclusions in meteorites, date to about 4.567 billion years.[^zirker2002-7][^amelin2002] Traces of short-lived isotopes such as iron-60 point to a nearby supernova at the time.[^williams2010] The collapsing fragment spun up as it shrank, and material with too much angular momentum to fall in formed the [[Protoplanetary_disk|protoplanetary disk]] from which the planets grew.[^glozman2022][^greaves2005] ### Main sequence Since reaching the main sequence the Sun has grown about 15% in radius and about 48% in luminosity, because helium accumulating in the core raises its mean molecular weight, the core contracts and heats, and fusion speeds up.[^carroll2017] It now brightens by about 1% every 100 million years, and within about a billion years that will begin to strip Earth of its surface water.[^kollipara2014] Its total main-sequence life is about 10 billion years.[^goldsmith2001] ### After core hydrogen exhaustion The Sun is too light to explode as a supernova. When core hydrogen runs out in about 5 billion years it will become a subgiant and then a red giant, reaching about 1.2 AU in radius, engulfing [[Mercury_(planet)|Mercury]] and [[Venus]] and, in one model, Earth as well, although the outcome for Earth depends on uncertain mass loss.[^schroder2008] After a helium flash and a period of core helium burning it will pass through the asymptotic giant branch, eject about half its mass as a planetary nebula and leave a white dwarf of about 0.54 solar masses that cools over trillions of years.[^schroder2008] ## Gravitational domain and influence The Sun holds eight planets, several dwarf planets, the [[Asteroid_belt|asteroid belt]], the comets and the icy bodies beyond [[Neptune]].[^encrenaz2004] Earth's distance from it ranges from 147.1 million km at perihelion in early January to 152.1 million km at aphelion in early July.[^nasa-sun][^usno-seasons] The astronomical unit, first defined from this distance, was fixed in 2012 as exactly 149,597,870,700 m.[^iau2012] The Sun is not fixed at the centre: the planets, above all [[Jupiter]] and [[Saturn]], move it around the Solar System's barycentre by up to about two solar radii, in a pattern that roughly repeats every 179 years.[^jose1965] Its gravity dominates that of neighbouring stars out to about two light-years, some 125,000 AU, beyond even the larger estimates for the [[Oort_cloud|Oort cloud]]; G. A. Chebotarev calculated its [[Hill_sphere|Hill sphere]] relative to the galactic centre at about 230,000 AU.[^encrenaz2004][^chebotarev1964] ## Overall location ### Celestial neighbourhood The Sun sits inside the [[Local_Bubble|Local Bubble]], a region of very hot, thin plasma, and the Solar System is currently embedded in a flow of warm, partly ionised gas belonging to the cluster of local clouds that includes the [[Local_Interstellar_Cloud|Local Interstellar Cloud]].[^frisch2011] It moves at about 19.4 km/s relative to the nearby stars.[^nasa-sun] The nearest star, Proxima Centauri in the [[Alpha_Centauri|Alpha Centauri]] system, is 1.3 parsecs, about 4.2 light-years, away.[^anglada2016] ### Galactic motion The Sun orbits the galactic centre at roughly 230 km/s and takes about 220–250 million years, a [[Galactic_year|galactic year]], to complete a circuit; it has done so about twenty times since it formed.[^nasa-starchild][^leong2002] Its motion relative to its neighbours, the solar apex, points roughly towards the star Vega.[^raymo1990] ## Observational history ### Early understanding Many ancient cultures treated the Sun as a god. Babylonian astronomers of the first millennium BC saw that its motion along the [[Ecliptic|ecliptic]] is not uniform, an effect now explained by Earth's elliptical [[Orbit|orbit]].[^leverington2003] Anaxagoras proposed that it was a huge fiery mass of metal, and Aristarchus of Samos placed it at the centre of the planetary system, an idea Copernicus developed in the sixteenth century.[^sider1973][^stahl1945][^openstax-astro] ### Development of scientific understanding In 1672 Cassini and Richer measured the parallax of Mars from Paris and Cayenne and derived an Earth–Sun distance only about 10% too small.[^rossi2024] The 1769 transit of Venus gave 93,726,900 miles, within 0.8% of the modern value.[^teets2003] [[Isaac_Newton|Isaac Newton]] split sunlight with a prism in 1666, William Herschel found infrared radiation beyond the red in 1800, and Norman Lockyer named helium in 1868 from an unexplained [[Spectral_line|spectral line]].[^bbc-newton][^coolcosmos][^parnel-helium] Kelvin's contraction theory gave the Sun an age of only tens of millions of years.[^thomson1862] Arthur Eddington suggested in 1920 that hydrogen fusing into helium supplies the energy, following [[Mass–energy_equivalence|mass–energy equivalence]], and Hans Bethe worked out the reactions in 1938–1939.[^esa-eddington][^bethe1938][^bethe1939] ### Solar space missions NASA's Pioneer 6–9 made the first long-term measurements of the solar wind from interplanetary space, and Pioneer 9 returned data until 1983.[^wade2008] The Helios probes of the 1970s studied the wind inside Mercury's orbit.[^burlaga2001] Skylab's Apollo Telescope Mount observed the transition region, coronal holes and early coronal mass ejections from 1973,[^burlaga2001] and SOHO, launched in 1995 to the Sun–Earth L1 point, has watched the Sun continuously since.[^dwivedi2006] Ulysses flew over the poles and found the high-latitude wind blowing at about 750 km/s, and Genesis returned samples of the solar wind.[^jpl-ulysses][^calaway2009] ## Religious aspects Solar deities appear in many mythologies.[^coleman2015] The Sumerians worshipped the Sun as Utu, later identified with the Semitic Shamash, a god of justice.[^black1992] In Egypt the Sun was Ra, and under Akhenaten the solar disc Aten became the pre-eminent god.[^teeter2011] The Greeks personified it as Helios, and in Japan the sun goddess Amaterasu is the principal deity of Shinto and the traditional ancestor of the imperial line.[^hesiod][^roberts2010] ## See also - [[Solar_wind]] - [[Heliosphere]] - [[Stellar_structure]] - [[Formation_and_evolution_of_the_Solar_System]] - [[Nuclear_fusion]] ## Notes Numbers use the short scale (one billion = 10⁹). Values marked "derived" are computed in this article from the cited data. ## References [^nasa-sun]: Williams, D. R. "Sun Fact Sheet". NASA Goddard Space Flight Center (last updated 9 May 2024; fetched 2026-09-18). https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html [^woolfson2000]: Woolfson, M. (2000). "The origin and evolution of the solar system". *Astronomy & Geophysics* 41: 1.12–1.19. https://doi.org/10.1046/j.1468-4004.2000.00012.x [^fu2003]: Fu, Q. (2003). "Radiation (solar)". In *Encyclopedia of Atmospheric Sciences*. Elsevier, pp. 1859–1863. https://doi.org/10.1016/B0-12-227090-8/00334-1 [^iau2012]: International Astronomical Union (2012). "Resolution B2 on the re-definition of the astronomical unit of length". http://www.iau.org/static/resolutions/IAU2012_English.pdf [^zirker2002-7]: Zirker, J. B. (2002). *Journey from the Center of the Sun*. Princeton University Press, pp. 7–8. ISBN 978-0-691-05781-1. [^goldsmith2001]: Goldsmith, D.; Owen, T. (2001). *The Search for Life in the Universe*. University Science Books, p. 96. ISBN 978-1-891389-16-0. [^schroder2008]: Schröder, K.-P.; Connon Smith, R. (2008). "Distant future of the Sun and Earth revisited". *Monthly Notices of the Royal Astronomical Society* 386: 155–163. https://doi.org/10.1111/j.1365-2966.2008.13022.x [^barnhart1995]: Barnhart, R. K. (1995). *The Barnhart Concise Dictionary of Etymology*. HarperCollins, p. 776. ISBN 978-0-06-270084-1. [^orel2003]: Orel, V. (2003). *A Handbook of Germanic Etymology*. Brill, p. 41. ISBN 978-90-04-12875-0. [^nasa-sol]: NASA (2006). "Opportunity's view, sol 959". https://www.nasa.gov/mission_pages/mer/images/pia01892.html [^allen2000]: Cox, A. N. (ed.) (2000). *Allen's Astrophysical Quantities*, 4th ed. Springer, p. 2. ISBN 978-0-387-98746-0. [^collins-heliology]: *Collins English Dictionary*. "Heliology". https://www.collinsdictionary.com/dictionary/english/heliology [^phillips1995-47]: Phillips, K. J. H. (1995). *Guide to the Sun*. Cambridge University Press, pp. 47–53. ISBN 978-0-521-39788-9. [^robles2008]: Robles, J. A.; Lineweaver, C. H.; Grether, D.; et al. (2008). "A comprehensive comparison of the Sun to other stars: searching for self-selection effects". *The Astrophysical Journal* 684: 691–706. https://doi.org/10.1086/589985 [^zeilik1998]: Zeilik, M. A.; Gregory, S. A. (1998). *Introductory Astronomy & Astrophysics*, 4th ed. Saunders College Publishing, p. 322. ISBN 978-0-03-006228-5. [^connelly2012]: Connelly, J. N.; Bizzarro, M.; Krot, A. N.; et al. (2012). "The absolute chronology and thermal processing of solids in the solar protoplanetary disk". *Science* 338: 651–655. https://doi.org/10.1126/science.1226919 [^gough2012]: Gough, D. (2012). "How oblate is the Sun?". *Science* 337: 1611–1612. https://doi.org/10.1126/science.1226988 [^meftah2015]: Meftah, M.; Irbah, A.; Hauchecorne, A.; et al. (2015). "On the determination and constancy of the solar oblateness". *Solar Physics* 290: 673–687. https://doi.org/10.1007/s11207-015-0655-6 [^phillips1995-78]: Phillips, K. J. H. (1995). *Guide to the Sun*. Cambridge University Press, pp. 78–79. ISBN 978-0-521-39788-9. [^guinan2009]: Guinan, E. F.; Engle, S. G. (2009). "The Sun in time: age, rotation, and magnetic activity of the Sun and solar-type stars and effects on hosted planets". *Proceedings of the IAU* 4(S258): 395–408. https://doi.org/10.1017/S1743921309032050 [^fossat2017]: Fossat, E.; Boumier, P.; Corbard, T.; et al. (2017). "Asymptotic g modes: evidence for a rapid rotation of the solar core". *Astronomy & Astrophysics* 604: A40. https://doi.org/10.1051/0004-6361/201730460 [^lodders2003]: Lodders, K. (2003). "Solar System abundances and condensation temperatures of the elements". *The Astrophysical Journal* 591: 1220–1247. https://doi.org/10.1086/375492 [^hansen2004]: Hansen, C. J.; Kawaler, S. D.; Trimble, V. (2004). *Stellar Interiors: Physical Principles, Structure, and Evolution*. Springer, pp. 19–20. ISBN 978-0-387-20089-7. [^garcia2007]: García, R. A.; Turck-Chièze, S.; Jiménez-Reyes, S. J.; et al. (2007). "Tracking solar gravity modes: the dynamics of the solar core". *Science* 316: 1591–1593. https://doi.org/10.1126/science.1140598 [^broggini2003]: Broggini, C. (2003). "Nuclear processes at solar energy". *Physics in Collision: Proceedings of the XXIII International Conference*, p. 21. http://www.slac.stanford.edu/econf/C030626 [^goupil2011]: Goupil, M. J.; Lebreton, Y.; Marques, J. P.; Samadi, R.; Baudin, F. (2011). "Open issues in probing interiors of solar-like oscillating main sequence stars 1. From the Sun to nearly suns". *Journal of Physics: Conference Series* 271: 012031. https://doi.org/10.1088/1742-6596/271/1/012031 [^shu1982]: Shu, F. H. (1982). *The Physical Universe: An Introduction to Astronomy*. University Science Books, p. 102. ISBN 978-0-935702-05-7. [^haubold1994]: Haubold, H. J.; Mathai, A. M. (1994). "Solar nuclear energy generation and the chlorine solar neutrino experiment". *AIP Conference Proceedings* 320: 102–116. https://doi.org/10.1063/1.47009 [^msfc-interior]: NASA Marshall Space Flight Center (2007). "The solar interior". Solar Physics. http://solarscience.msfc.nasa.gov/interior.shtml [^nasa-sunlight]: NASA Sun–Earth Day (2007). "Ancient sunlight". *Technology Through Time*. http://sunearthday.nasa.gov/2007/locations/ttt_sunlight.php [^tobias2005]: Tobias, S. M. (2005). "The solar tachocline: formation, stability and its role in the solar dynamo". In Soward, A. M.; et al. (eds.), *Fluid Dynamics and Dynamos in Astrophysics and Geophysics*. CRC Press, pp. 193–235. ISBN 978-0-8493-3355-2. [^abhyankar1977]: Abhyankar, K. D. (1977). "A survey of the solar atmospheric models". *Bulletin of the Astronomical Society of India* 5: 40–44. http://prints.iiap.res.in/handle/2248/510 [^erdelyi2007]: Erdélyi, R.; Ballai, I. (2007). "Heating of the solar and stellar coronae: a review". *Astronomische Nachrichten* 328: 726–733. https://doi.org/10.1002/asna.200710803 [^kasper2021]: Kasper, J. C.; Klein, K. G.; Lichko, E.; et al. (2021). "Parker Solar Probe enters the magnetically dominated solar corona". *Physical Review Letters* 127: 255101. https://doi.org/10.1103/PhysRevLett.127.255101 [^parker2007]: Parker, E. N. (2007). "The heliosphere". In Kamide, Y.; Chian, A. C.-L. (eds.), *Handbook of the Solar-Terrestrial Environment*. Springer. https://doi.org/10.1007/978-3-540-46315-3 [^jpl-voyager]: NASA Jet Propulsion Laboratory. "Voyager: interstellar mission". https://voyager.jpl.nasa.gov/mission/interstellar-mission/ [^pmod2006]: PMOD/WRC (2006). "Construction of a composite total solar irradiance (TSI) time series from 1978 to present". Physikalisch-Meteorologisches Observatorium Davos. http://www.pmodwrc.ch/pmod.php?topic=tsi/composite/SolarConstant [^dwivedi2006]: Dwivedi, B. N. (2006). "Our ultraviolet Sun". *Current Science* 91: 587–595. http://www.iisc.ernet.in/currsci/sep102006/587.pdf [^schlattl2001]: Schlattl, H. (2001). "Three-flavor oscillation solutions for the solar neutrino problem". *Physical Review D* 64: 013009. https://doi.org/10.1103/PhysRevD.64.013009 [^zirker2002-119]: Zirker, J. B. (2002). *Journey from the Center of the Sun*. Princeton University Press, pp. 119–120. ISBN 978-0-691-05781-1. [^russell2001]: Russell, C. T. (2001). "Solar wind and interplanetary magnetic field: a tutorial". In Song, P.; Singer, H. J.; Siscoe, G. L. (eds.), *Space Weather*, Geophysical Monograph 125. American Geophysical Union, pp. 73–88. http://www-ssc.igpp.ucla.edu/personnel/russell/papers/SolWindTutorial.pdf [^gsfc-sunspot]: NASA Goddard Space Flight Center (2001). "The largest sunspot in ten years". http://www.gsfc.nasa.gov/gsfc/spacesci/solarexp/sunspot.htm [^zirker2002-120]: Zirker, J. B. (2002). *Journey from the Center of the Sun*. Princeton University Press, pp. 120–127. ISBN 978-0-691-05781-1. [^eddy1976]: Eddy, J. A. (1976). "The Maunder minimum". *Science* 192: 1189–1202. https://doi.org/10.1126/science.192.4245.1189 [^lean1992]: Lean, J.; Skumanich, A.; White, O. (1992). "Estimating the Sun's radiative output during the Maunder minimum". *Geophysical Research Letters* 19: 1591–1594. https://doi.org/10.1029/92GL01578 [^amelin2002]: Amelin, Y.; Krot, A. N.; Hutcheon, I. D.; Ulyanov, A. A. (2002). "Lead isotopic ages of chondrules and calcium-aluminum-rich inclusions". *Science* 297: 1678–1683. https://doi.org/10.1126/science.1073950 [^williams2010]: Williams, J. (2010). "The astrophysical environment of the solar birthplace". *Contemporary Physics* 51: 381–396. https://doi.org/10.1080/00107511003764725 [^carroll2017]: Carroll, B. W.; Ostlie, D. A. (2017). *An Introduction to Modern Astrophysics*, 2nd ed. Cambridge University Press, pp. 350, 447–457. ISBN 978-1-108-42216-1. [^kollipara2014]: Kollipara, P. (2014). "Earth won't die as soon as thought". *Science*, 22 January 2014. https://www.science.org/content/article/earth-wont-die-soon-thought [^encrenaz2004]: Encrenaz, T.; Bibring, J.-P.; Blanc, M.; et al. (2004). *The Solar System*, 3rd ed. Springer, p. 1. [^usno-seasons]: U.S. Naval Observatory. "Earth's seasons: equinoxes, solstices, perihelion, and aphelion". https://aa.usno.navy.mil/data/Earth_Seasons [^jose1965]: Jose, P. D. (1965). "Sun's motion and sunspots". *The Astronomical Journal* 70: 193–200. https://doi.org/10.1086/109714 [^chebotarev1964]: Chebotarev, G. A. (1964). "Gravitational spheres of the major planets, Moon and Sun". *Soviet Astronomy* 7: 618. https://adsabs.harvard.edu/full/1964SvA.....7..618C [^cohen1998]: Cohen, H. (1998). "Table of temperatures, power densities, luminosities by radius in the Sun". Contemporary Physics Education Project. http://fusedweb.llnl.gov/CPEP/Chart_Pages/5.Plasmas/Sunlayers.html [^worldbook]: "Sun". *World Book* at NASA. http://mynasa.nasa.gov/worldbook/sun_worldbook.html [^pantolmos2017]: Pantolmos, G.; Matt, S. P. (2017). "Magnetic braking of Sun-like and low-mass stars: dependence on coronal temperature". *The Astrophysical Journal* 849: 83. https://doi.org/10.3847/1538-4357/aa9061 [^hansen2004-9]: Hansen, C. J.; Kawaler, S. D.; Trimble, V. (2004). *Stellar Interiors*, sec. 9.2.3. Springer. ISBN 978-0-387-20089-7. [^stanford-color]: Stanford Solar Center. "What color is the Sun?". http://solar-center.stanford.edu/SID/activities/GreenSun.html [^white1971]: White, T. J.; Mainster, M. A.; Wilson, P. W.; Tips, J. H. (1971). "Chorioretinal temperature increases from solar observation". *Bulletin of Mathematical Biophysics* 33: 1–17. https://doi.org/10.1007/BF02476660 [^macdonald2012]: Macdonald, L. (2012). *How to Observe the Sun Safely*. Springer, p. 17. https://doi.org/10.1007/978-1-4614-3825-0_2 [^phillips1995-14]: Phillips, K. J. H. (1995). *Guide to the Sun*. Cambridge University Press, pp. 14–15, 34–38. ISBN 978-0-521-39788-9. [^barsh2003]: Barsh, G. S. (2003). "What controls variation in human skin color?". *PLOS Biology* 1: e27. https://doi.org/10.1371/journal.pbio.0000027 [^hale1919]: Hale, G. E.; Ellerman, F.; Nicholson, S. B.; Joy, A. H. (1919). "The magnetic polarity of sun-spots". *The Astrophysical Journal* 49: 153. https://doi.org/10.1086/142452 [^glozman2022]: Glozman, I. (2022). "Formation of the Solar System". Highline College. https://people.highline.edu/iglozman/classes/astronotes/solsys_form.htm [^greaves2005]: Greaves, J. S. (2005). "Disks around stars and the growth of planetary systems". *Science* 307: 68–71. https://doi.org/10.1126/science.1101979 [^frisch2011]: Frisch, P. C.; Redfield, S.; Slavin, J. D. (2011). "The interstellar medium surrounding the Sun". *Annual Review of Astronomy and Astrophysics* 49: 237–279. https://doi.org/10.1146/annurev-astro-081710-102613 [^anglada2016]: Anglada-Escudé, G.; Amado, P. J.; Barnes, J.; et al. (2016). "A terrestrial planet candidate in a temperate orbit around Proxima Centauri". *Nature* 536: 437–440. https://doi.org/10.1038/nature19106 [^bethe1938]: Bethe, H. A.; Critchfield, C. L. (1938). "The formation of deuterons by proton combination". *Physical Review* 54: 248–254. https://doi.org/10.1103/PhysRev.54.248 [^elsharkawi2005]: El-Sharkawi, M. A. (2005). *Electric Energy: An Introduction*. CRC Press, pp. 87–88. ISBN 978-0-8493-3078-0. [^nasa-starchild]: NASA StarChild (2000). "Does the Sun move around the Milky Way?". http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question18.html [^leong2002]: Leong, S. (2002). "Period of the Sun's orbit around the galaxy (cosmic year)". *The Physics Factbook*. http://hypertextbook.com/facts/2002/StacyLeong.shtml [^raymo1990]: Raymo, C. (1990). *365 Starry Nights: An Introduction to Astronomy for Every Night of the Year*. Touchstone, p. 114. ISBN 978-0-671-76606-1. [^leverington2003]: Leverington, D. (2003). *Babylon to Voyager and Beyond: A History of Planetary Astronomy*. Cambridge University Press, pp. 6–7. ISBN 978-0-521-80840-8. [^sider1973]: Sider, D. (1973). "Anaxagoras on the size of the Sun". *Classical Philology* 68: 128–129. https://doi.org/10.1086/365951 [^stahl1945]: Stahl, W. H. (1945). "The Greek heliocentric theory and its abandonment". *Transactions and Proceedings of the American Philological Association* 76: 321–332. https://doi.org/10.2307/283344 [^openstax-astro]: Fraknoi, A.; Morrison, D.; Wolff, S. (2022). *Astronomy 2e*, sec. 2.4 "The birth of modern astronomy". OpenStax. https://openstax.org/books/astronomy-2e/pages/2-4-the-birth-of-modern-astronomy [^rossi2024]: Rossi, E. (2024). *Unveiling the Size of the Universe: The First Accurate Measurement of the Earth–Sun Distance by Giovanni Domenico Cassini*. FedOA – Federico II University Press. https://doi.org/10.6093/978-88-6887-277-9 [^teets2003]: Teets, D. (2003). "Transits of Venus and the astronomical unit". *Mathematics Magazine* 76: 335–348. https://doi.org/10.1080/0025570X.2003.11953207 [^bbc-newton]: BBC Teach. "Sir Isaac Newton (1643–1727)". https://www.bbc.co.uk/teach/articles/zh8792p [^coolcosmos]: IPAC Cool Cosmos. "Herschel discovers infrared light". http://coolcosmos.ipac.caltech.edu/cosmic_classroom/classroom_activities/herschel_bio.html [^parnel-helium]: Parnell, C. "Discovery of helium". University of St Andrews. http://www-solar.mcs.st-andrews.ac.uk/~clare/Lockyer/helium.html [^thomson1862]: Thomson, W. (1862). "On the age of the Sun's heat". *Macmillan's Magazine* 5: 388–393. http://zapatopi.net/kelvin/papers/on_the_age_of_the_suns_heat.html [^esa-eddington]: European Space Agency (2005). "Studying the stars, testing relativity: Sir Arthur Eddington". http://www.esa.int/esaSC/SEMDYPXO4HD_index_0.html [^bethe1939]: Bethe, H. A. (1939). "Energy production in stars". *Physical Review* 55: 434–456. https://doi.org/10.1103/PhysRev.55.434 [^wade2008]: Wade, M. (2008). "Pioneer 6-7-8-9-E". *Encyclopedia Astronautica*. http://www.astronautix.com/craft/pio6789e.htm [^burlaga2001]: Burlaga, L. F. (2001). "Magnetic fields and plasmas in the inner heliosphere: Helios results". *Planetary and Space Science* 49: 1619–1627. https://doi.org/10.1016/S0032-0633(01)00098-8 [^jpl-ulysses]: NASA/JPL (2005). "Ulysses: primary mission results". http://ulysses.jpl.nasa.gov/science/mission_primary.html [^calaway2009]: Calaway, M. J.; Stansbery, E. K.; Keller, L. P. (2009). "Genesis capturing the Sun: solar wind irradiation at Lagrange 1". *Nuclear Instruments and Methods in Physics Research B* 267: 1101–1108. https://doi.org/10.1016/j.nimb.2009.01.132 [^coleman2015]: Coleman, J. A.; Davidson, G. (2015). *The Dictionary of Mythology: An A–Z of Themes, Legends, and Heroes*. Arcturus, p. 316. ISBN 978-1-78404-478-7. [^black1992]: Black, J.; Green, A. (1992). *Gods, Demons and Symbols of Ancient Mesopotamia: An Illustrated Dictionary*. British Museum Press, pp. 182–184. ISBN 978-0-7141-1705-8. [^teeter2011]: Teeter, E. (2011). *Religion and Ritual in Ancient Egypt*. Cambridge University Press. ISBN 978-0-521-84855-8. [^hesiod]: Hesiod. *Theogony*, line 371. Perseus Digital Library. https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0130%3Acard%3D371 [^roberts2010]: Roberts, J. (2010). *Japanese Mythology A to Z*, 2nd ed. Chelsea House, pp. 4–5. ISBN 978-1-60413-435-3. ## Further reading - Zirker, J. B. (2002). *Journey from the Center of the Sun*. Princeton University Press. ISBN 978-0-691-05781-1. - Phillips, K. J. H. (1995). *Guide to the Sun*. Cambridge University Press. ISBN 978-0-521-39788-9. ## External links - NASA Science: the Sun — https://science.nasa.gov/sun/ - NASA Solar Dynamics Observatory — https://sdo.gsfc.nasa.gov/ - ESA/NASA SOHO — https://soho.nascom.nasa.gov/ - NOAA Space Weather Prediction Center — https://www.swpc.noaa.gov/ *Article prose: Solar System portal child articles, wave 1, 2026-09-18 · row SOL-008 · strict pair pinned at revision [1375342983](https://en.wikipedia.org/w/index.php?oldid=1375342983). The sections below this block are the page's earlier material, kept in place.* <!-- SOLART:END --> ## Microsim To Do *Claimable rows, house pattern. All real Wikipedia articles.* - Solar wind - Solar constant - Sunspot - Solar flare - Parker Solar Probe <!-- REAL-GENERATIVE-MEDIA:START --> ## Links (Wikipedia order) <!-- injected from _registry/childlinks/Sun.json (2026-07-30T02:09:12Z) --> `10_Hygiea` · `120347_Salacia` · `174567_Varda` · `1769_transit_of_Venus_observed_from_Tahiti` · `2013_ND15` · `2019_UO14` · `2060_Chiron` · `208996_Achlys` · `28978_Ixion` · `2_Pallas` · `307261_Máni` · `4_Vesta` · `532037_Chiminigagua` · `55565_Aya` · `A-type_main-sequence_star` · `ACRIMSAT` · `ADAHELI` · `AIP_Conference_Proceedings` · `Absolute_magnitude` · `Abundance_of_the_chemical_elements` · `Academic_Press` · `Accretion_(astrophysics)` · `Accretion_disk` · `Active_asteroid` · `Active_region` · `Aditya-L1` · `Advanced_Composition_Explorer` · `Advanced_Space-based_Solar_Observatory` · `Akhenaten` · `Al-Battani` · `Albert_Einstein` · `Alfvén_Mach_number` · `Alfvén_surface` · `Alfvén_wave` · `Alpha_Centauri` · `Alpha_Centauri_Ab` · 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`Large_Binocular_Telescope` · `Late_Heavy_Bombardment` · `Latin` · `Latitude` · `Lead_star` · `Lexico` · `Life` · `Light-year` · `List_of_Arabic_star_names` · `List_of_Earth-crossing_asteroids` · `List_of_French_astronomers` · `List_of_Jupiter-crossing_minor_planets` · `List_of_Jupiter_trojans_(Greek_camp)` · `List_of_Jupiter_trojans_(Trojan_camp)` · `List_of_Mars-crossing_minor_planets` · `List_of_Mercury-crossing_minor_planets` · `List_of_Russian_astronomers_and_astrophysicists` · `List_of_Solar_System_objects` · `List_of_Solar_System_objects_by_size` · `List_of_Solar_System_probes` · `List_of_Venus-crossing_minor_planets` · `List_of_astronomers` · `List_of_astronomical_catalogues` · `List_of_brightest_natural_objects_in_the_sky` · `List_of_brightest_stars` · `List_of_brown_dwarfs` · `List_of_coolest_stars` · `List_of_crewed_spacecraft` · `List_of_exceptional_asteroids` · `List_of_gravitationally_rounded_objects_of_the_Solar_System` · `List_of_heliophysics_missions` · `List_of_hottest_stars` · `List_of_hypothetical_Solar_System_objects` · `List_of_interstellar_and_circumstellar_molecules` · `List_of_largest_stars` · `List_of_missions_to_comets` · `List_of_most_distant_stars` · `List_of_most_luminous_stars` · `List_of_most_massive_stars` · `List_of_multiplanetary_systems` · `List_of_natural_satellites` · `List_of_nearest_bright_stars` · `List_of_nearest_stars` · `List_of_novae_in_the_Milky_Way_galaxy` · `List_of_planetary_nebulae` · `List_of_possible_dwarf_planets` · `List_of_proper_names_of_stars` · `List_of_red_dwarfs` · `List_of_smallest_known_stars` · `List_of_solar_cycles` · `List_of_solar_deities` · `List_of_star_extremes` · `List_of_stars_with_resolved_images` · `List_of_supernova_candidates` · `List_of_supernova_remnants` · `List_of_supernovae` · `List_of_topics_in_space` · `List_of_unsolved_problems_in_astronomy` · `List_of_white_dwarfs` · `List_of_women_astronomers` · `Lists_of_stars` · `Lists_of_telescopes` · `Lithium_burning` · `Lithuanian_language` · `Little_Ice_Age` · `Local_Bubble` · `Local_Group` · `Local_Hole` · `Local_Interstellar_Cloud` · `Local_Sheet` · `Local_Volume` · `Lord_Kelvin` · `Low_German` · `Luhman_16` · `Lumen_(unit)` · `Luminosity` · `Luminous_blue_variable` · `Luminous_efficacy` · `Luminous_red_nova` · `Lunar_eclipse` · `Lunar_resources` · [[Magnesium]] · `Magnetar` · `Magnetic_field` · `Magnetic_reconnection` · `Magnetic_switchback` · `Magnitude_(astronomy)` · `Main_sequence` · `Makemake` · `Margaret_Burbidge` · [[Mars]] · `Mars_trojan` · `Marshall_Space_Flight_Center` · `Mass` · `Mass–energy_equivalence` · `Matter` · `Maya_astronomy` · `Meanings_of_minor-planet_names` · `Megalith` · `Meghnad_Saha` · `Mercury_(planet)` · `Mercury–manganese_star` · `Messiah` · `Metallicity` · `Meteorite` · `Meteoroid` · `Micronova` · `Microturbulence` · `Midnight_sun` · `Mie_scattering` · `Milky_Way` · `Mimas` · `Minor-planet_moon` · `Minor_planet` · `Miranda_(moon)` · `Molecular_cloud` · `Molecules_in_stars` · `Moment_of_inertia_factor` · `Monthly_Notices_of_the_Royal_Astronomical_Society` · [[Moon]] · `Moonlet` · `Moons_of_Haumea` · `Moons_of_Jupiter` · `Moons_of_Mars` · `Moons_of_Neptune` · `Moons_of_Pluto` · `Moons_of_Saturn` · `Moons_of_Uranus` · `Moreton_wave` · `Multi-messenger_astronomy` · `Myriad` · `NASA` · `Nabta_Playa` · `Naked_eye` · `Namaka_(moon)` · `Names_of_the_days_of_the_week` · `Nanoflare` · `Natural_satellite` · `Nature_(journal)` · `Near-Earth_object` · `Nebular_hypothesis` · `Neith_(hypothetical_moon)` · `Nemesis_(hypothetical_star)` · [[Neon]] · `Neon-burning_process` · `Neptune` · `Neptune_trojan` · `Nereid_(moon)` · `Neutrino` · `Neutrino_astronomy` · `Neutrino_oscillation` · `Neutron_star` · `Neutron_star_merger` · `New_Kingdom_of_Egypt` · `New_Scientist` · `Newgrange` · `Nibiru_cataclysm` · `Nice_2_model` · `Nice_model` · `Nicolaus_Copernicus` · [[Nitrogen]] · `Nix_(moon)` · `Norman_Lockyer` · `Nova` · `Nova_remnant` · [[Nuclear_fusion]] · `Nuclear_transmutation` · `Nucleocosmochronology` · [[Nucleosynthesis]] · `O-type_main-sequence_star` · `OB_star` · `OH/IR_star` · `Oberon_(moon)` · `Observable_universe` · `Observational_astronomy` · `Observations_and_explorations_of_Venus` · `Old_English` · `Old_Norse` · `Oort_cloud` · `Oort_limit` · `Open_cluster` · `Opposition_(astronomy)` · `Optical_phenomenon` · `Optical_telescope` · `Optics` · `Orbital_speed` · `Orbiting_Solar_Observatory` · `Orcus_(dwarf_planet)` · `Orion_Arm` · `Outer_space` · `Outline_of_astronomy` · `Outline_of_space_exploration` · `Outline_of_the_Solar_System` · `Oxford_English_Dictionary` · `Oxford_University_Press` · [[Oxygen]] · `Oxygen-burning_process` · `Ozone_layer` · `P-process` · `PG_1159_star` · `PLOS_Biology` · `Parker_Solar_Probe` · `Parsec` · `Persian_astronomy` · `Persian_language` · `Perturbation_(astronomy)` · `Phaeton_(hypothetical_planet)` · `Phobos_(moon)` · `Phoebe_(moon)` · `Phosphene` · `Photographic_magnitude` · `Photometric-standard_star` · `Photometric_system` · `Photometry_(astronomy)` · `Photosphere` · `Photosynthesis` · `Physical_Review` · `Physical_cosmology` · `Physics_Reports` · `Pioneer_6,_7,_8,_and_9` · `Pioneer_H` · `Pisces–Cetus_Supercluster_Complex` · `Planck_star` · `Planet` · `Planet_Nine` · `Planet_V` · `Planetarium` · `Planetary_geology` · `Planetary_migration` · `Planetary_nebula` · `Planetary_objects_proposed_in_religion,_astrology,_ufology_and_pseudoscience` · [[Planetary_system]] · `Planetesimal` · `Planets_beyond_Neptune` · `Planets_in_astrology` · [[Plasma_(physics)]] · `Plutino` · `Pluto` · `Pole_star` · `Poles_of_astronomical_bodies` · `Post-AGB_star` · `Potentially_hazardous_object` · `Pre-main-sequence_star` · `Princeton_University_Press` · `Prism_(optics)` · `Proper_motion` · `Proplyd` · `Proteus_(moon)` · [[Proton]] · `Proton–proton_chain` · `Protoplanetary_disk` · `Protoplanetary_nebula` · `Protostar` · `Proxima_Centauri` · `Proxima_Centauri_b` · `Ptolemy` · `Public_domain` · `Pulsar` · `Pyramid` · `Q_star` · `Quantum_cosmology` · `Quaoar` · `Quark_star` · `Quasi-star` · `R-process` · `Radar_astronomy` · `Radial_velocity` · `Radiance` · `Radiation` · `Radiative_zone` · `Radio-quiet_neutron_star` · `Radio_astronomy` · `Radio_telescope` · [[Radioactive_decay]] · `Radius` · `Rayleigh_scattering` · `Red-giant_branch` · `Red_clump` · `Red_dwarf` · `Red_giant` · `Red_supergiant` · `Refraction` · `Reuven_Ramaty_High_Energy_Solar_Spectroscopic_Imager` · `Reviews_of_Modern_Physics` · `Rhea_(moon)` · `Rho_Ophiuchi_cloud_complex` · `Right_ascension` · `Ring_system` · `Rings_of_Chariklo` · `Rings_of_Earth` · `Rings_of_Jupiter` · `Rings_of_Neptune` · `Rings_of_Rhea` · `Rings_of_Saturn` · `Rings_of_Uranus` · `Roche_limit` · `Rogue_planet` · `Roman_Empire` · `Rubble_pile` · `S-process` · `S-type_star` · `S/2015_(136472)_1` · `SOLAR_(ISS)` · `STEREO` · `STS-41-C` · `STS-87` · `Sabbath` · `Sample-return_mission` · `Sanskrit` · `Satellite_galaxies_of_the_Milky_Way` · `Saturn` · `Scattered_disc` · `Scholarpedia` · [[Science_(journal)]] · `Sedna_(dwarf_planet)` · `Sednoid` · `Seleucus_of_Seleucia` · `Serbian_folk_astronomy` · `Shamash` · `Shear_stress` · `Shell_star` · `Shinto` · `Shock_wave` · `Sidewalk_astronomy` · [[Silicon]] · `Silicon-burning_process` · `Sirius` · `Skin_cancer` · `Slavic_languages` · `Small_Solar_System_body` · `Soft_gamma_repeater` · `Solar-like_oscillations` · `Solar_Dynamics_Observatory` · `Solar_Maximum_Mission` · `Solar_Orbiter` · `Solar_Polar_Orbit_Observatory` · `Solar_System` · `Solar_System_model` · `Solar_analog` · `Solar_and_Heliospheric_Observatory` · `Solar_apex` · `Solar_constant` · `Solar_core` · `Solar_corona` · `Solar_cycle` · `Solar_deity` · `Solar_dynamo` · `Solar_eclipse` · `Solar_energy` · `Solar_facula` · `Solar_flare` · `Solar_granule` · `Solar_irradiance` · `Solar_luminosity` · `Solar_mass` · `Solar_maximum` · `Solar_minimum` · `Solar_moss` · `Solar_neutrino` · `Solar_neutrino_problem` · `Solar_observation` · `Solar_phenomena` · `Solar_physics` · `Solar_plage` · `Solar_prominence` · `Solar_radio_emission` · `Solar_radius` · `Solar_rotation` · `Solar_spicule` · `Solar_telescope` · `Solar_time` · `Solar_transition_region` · `Solar_wind` · `Solar_wind_turbulence` · `Solstice` · `Southern_African_Large_Telescope` · `Space_Science_Reviews` · `Space_Shuttle_Challenger` · `Space_climate` · `Space_colonization` · `Space_exploration` · `Space_probe` · `Space_station` · `Space_telescope` · `Space_weather` · `Space_weather_Observations_at_L1_to_Advance_Readiness_-_1` · `Sphere_of_influence_(astrodynamics)` · `Spherical_astronomy` · `Springer_Science+Business_Media` · `Standard_German` · `Standard_gravity` · `Standard_solar_model` · `Star` · `Star_cluster` · `Star_formation` · `Star_system` · `Starlight` · `Starspot` · `Stellar-wind_bubble` · `Stellar_atmosphere` · `Stellar_black_hole` · `Stellar_classification` · `Stellar_collision` · `Stellar_core` · `Stellar_corona` · `Stellar_designations_and_names` · `Stellar_dynamics` · `Stellar_engulfment` · `Stellar_evolution` · `Stellar_kinematics` · `Stellar_magnetic_field` · `Stellar_mass` · `Stellar_mass_loss` · `Stellar_nucleosynthesis` · `Stellar_parallax` · `Stellar_population` · `Stellar_rotation` · `Stellar_structure` · `Stellar_wind` · `Stephen_Hawking` · `Stonehenge` · `Strange_star` · `Strömgren_sphere` · `Styx_(moon)` · `Sub-brown_dwarf` · `Subdwarf` · `Subdwarf_B_star` · `Subdwarf_O_star` · `Subgiant` · `Submillimetre_astronomy` · `Subrahmanyan_Chandrasekhar` · `Subsatellite` · `Substellar_object` · [[Sulfur]] · `Sumer` · [[Sun]] · `Sun_in_fiction` · `Sun_path` · `Sun_tanning` · `Sunburn` · `Sungrazing_comet` · `Sunlight` · `Sunspot` · `Sunspot_number` · `Super-AGB_star` · `Super_star_cluster` · `Supergiant` · `Supergranulation` · `Superluminous_supernova` · `Supermassive_black_hole` · `Supernatural` · `Supernova` · `Supernova_nucleosynthesis` · `Supra-arcade_downflows` · `Surface` · `Surface_area` · `Surface_gravity` · `Surya` · `Swedish_language` · `Symbiotic_binary` · `Symbiotic_nova` · `Synestia` · `Syzygy_(astronomy)` · `TRACE` · `T_Tauri_star` · `Tachocline` · `Taurus_molecular_cloud` · `Technetium_star` · `Telescope` · `Terrestrial_planet` · `Tesla_(unit)` · `Tethys_(moon)` · `Thames_&_Hudson` · `The_Astronomical_Journal` · `The_Astrophysical_Journal` · `Theia_(hypothetical_planet)` · `Themis_(hypothetical_moon)` · `Thermal_energy` · `Thermal_expansion` · `Thermal_radiation` · `Thomas_Harriot` · `Thorne–Żytkow_object` · `Thérèse_Encrenaz` · `Tibetan_astronomy` · `Tidal_disruption_event` · `Tidal_locking` · `Timeline_of_Solar_System_exploration` · `Timeline_of_astronomy` · `Timeline_of_discovery_of_Solar_System_planets_and_their_moons` · `Timeline_of_stellar_astronomy` · `Timeline_of_the_far_future` · `Titan_(moon)` · `Titania_(moon)` · `Trans-Neptunian_object` · `Transit_of_Venus` · `Trefoil` · `Trigonometry` · `Triple-alpha_process` · `Triton_(moon)` · `Trojan_(celestial_body)` · `Tyche_(hypothetical_planet)` · `Ultraviolet` · `Ultraviolet_astronomy` · `Ulysses_(spacecraft)` · `Umbriel` · `Universe` · [[Uranium]] · `Uranus` · `Vanth_(moon)` · `Variable_star` · [[Velocity]] · [[Venus]] · `Very_Large_Telescope` · `Virgo_Supercluster` · `Virial_theorem` · `Visible-light_astronomy` · `Vitamin_D` · `Volume` · `Voyager_1` · `Vulcan_(hypothetical_planet)` · `Vulcanoid` · `W._M._Keck_Observatory` · `WISE_0855−0714` · `Walter_Burkert` · `Watt` · [[Wayback_Machine]] · `Welsh_language` · `Weywot` · `White` · `White_dwarf` · `White_hole` · `William_Alfred_Fowler` · `William_Herschel` · `Wind_(spacecraft)` · `Winter_solstice` · `Wolf–Rayet_nebula` · `Wolf–Rayet_star` · `X-ray` · `X-ray_astronomy` · `X-ray_binary` · `X-ray_burster` · `X-ray_pulsar` · `X-ray_telescope` · `Xiangliu_(moon)` · `Yellow_hypergiant` · `Yellow_supergiant` · `Young_stellar_object` · `Zenith` · `Zodiac` ## Plate !Sun plate.svg *Engraved plate: MTN / Wikitube.io original · CC BY-SA 4.0.* ## Plate !Sun plate.svg > **Official MAIN — the star.** Energy survey of the Space Mining In Minnesota CoE, on the Technate Expansion schema — the ORIGIN of every heliocentric frame in the survey (the one body addressed FROM everywhere). Sibling surveys: the 14-body index. ## Mining Survey **Confirmed resources.** The Sun is not mined, it is HARVESTED: total solar irradiance at Earth orbit is approximately 1361 W/m² (the solar constant). The solar wind—a continuous stream of charged particles escaping the Sun's corona—is the primary mining vector: it implanted helium-3 in the lunar regolith over 4 billion years, making every He-3 mine downstream of this star and indebted to its heliospheric architecture. Solar power generation (photovoltaics, thermal collectors, concentrators) represents the baseline energy budget for every other body in the survey; in the long horizon, solar-powered stations orbit the Sun and feed power outward. **Extraction constraints.** You do not land on the Sun; the engineering challenge is orbital mechanics and thermodynamic: photovoltaic arrays orbit at 1 AU and radiate excess heat to space; solar thermal collectors operate at the limb where coronal heating approaches; advanced concepts (statites, light-sails, Dyson swarms) require orbital dynamics at scales from microsats to megastructures. The corona's magnetic complexity means solar cycles, flares, and coronal mass ejections introduce hazard windows into any long-term orbital station. **Survey status.** The Sun is the best-observed body in the entire inventory: continuous monitoring via the Solar Dynamics Observatory (SDO), SOHO, and the Parker Solar Probe, which has touched the solar corona itself. Carrington rotation tracking, magnetogram maps, sunspot catalogs, and flare classification systems are operationalized worldwide. ## Coordinate Frame Carrington heliographic (rotating frame fixed to solar surface features, period ~25.38 days); Stonyhurst heliographic (Earth-based, latitude relative to solar equator). Atlas: `Interplanetary-Atlas/Bodies/Sun` (harvest complete; coords UNVERIFIED pending Mac pass). ## Semiotic Vocabulary <!-- SEMIOTIC-VOCAB:START --> | Term | Notation / glyph | Sign system | Meaning at this body | |------|------------------|-------------|----------------------| | Solar symbol | ☉ (U+2609 circled dot) | astronomical symbols | The oldest continuous astronomical glyph in Western notation; represents the Sun as the center of the heliocentric system; appears in classical astrology and modern astronomical diagrams. | | Carrington rotation number | CR (integer; e.g., CR 2281) | astronomical notation | Solar surface rotation tracking system; numbered since Jan. 1853; increments every ~27.3 days (Carrington's observed period); the reference frame for sunspot catalogs and coronal feature tracking. | | Butterfly diagram | Latitude vs. time scatter plot | phase diagrams | Sunspot position time-series showing the 11-year cycle (Schwabe cycle); sunspots begin at high latitudes (~±35°) and drift toward the equator over the cycle; reflects the Sun's differential rotation and magnetic dynamo. | | McIntosh sunspot classification | Letter code (e.g., Aarh, Bhxx, Cro) | hazard pictograms ghs | Five-letter classification of sunspot morphology (area, spot count, umbra/penumbra complexity, tilt orientation, penumbra structure); predicts flare/CME likelihood; in operational use by NOAA/SWPC. | | GOES flare class | A, B, C, M, X (+ 1–9 subgrade) | hazard pictograms ghs | X-ray flux scale for solar flares (GOES satellite X-ray sensor, 1–8 Å band); X-class flares are the strongest (>10⁻³ W/m²); used for space-weather alerts and coronal mass ejection (CME) forecasting. | | Solar constant | 1361 W/m² (±0.5%) | phase diagrams + physical quantities | Total solar irradiance at Earth's mean distance (1 AU); sets the baseline energy budget for all heliocentric orbits; defined and refined by satellite radiometry since 1978 (VIRGO, TIM instruments). | | Astronomical unit (AU) | 1 AU ≈ 1.496×10¹¹ m | geographic notation | Distance Earth–Sun; the primary length scale for the inner solar system and the reference orbit for solar-constant irradiance; IAU definition (2012) fixed at exactly 1.496×10¹¹ m. | | Magnetogram polarity shading | Dark (−) and light (+) regions on solar disk | phase diagrams | Maps of the photospheric magnetic field showing bipolar sunspot pairs (N and S poles of emerging flux tubes); computed from Zeeman effect line-core measurements; SOHO/MDI and SDO/HMI are the operational sources. | | Helium-3 solar wind implantation | ³He (or ³₂He) implanted in regolith | nuclear symbols | Solar wind particles, including rare ³He (enriched in the corona), embed in airless-body regolith over billions of years; lunar concentration ~1 ppb; the mechanism that made the Moon and asteroids the He-3 repositories that ground terrestrial mining (Topaz discovery, Minnesota). | | Coronal mass ejection (CME) | Eruptive release of plasma and field | hazard pictograms ghs | Large-scale release of magnetized plasma from the solar corona, often associated with flares; travel time to Earth ~40 min–3 days; drive geomagnetic storms and radiation hazards to orbital infrastructure. | | Heliosphere | Sphere of solar-wind influence | geographic notation | Region around the Sun where the solar wind dominates; extends to the heliopause (~120 AU), marking the boundary with the interstellar medium; the primary energy and particle source for all inner-solar-system mining operations. | | Photosphere | Visible solar "surface" (at τ ≈ 1) | phase diagrams | The layer from which visible light escapes; effective temperature ~5778 K; where sunspots and granulation occur; the reference level for heliographic coordinates. | | Corona | Hot outer atmosphere (~1–3 MK) | phase diagrams | Region above the chromosphere where the magnetic field dominates and plasma is confined; source of the solar wind and most high-energy radiation; its heating mechanism remains an active research frontier. | <!-- SEMIOTIC-VOCAB:END --> ## From the Real GENERATIVE library > The Sun is the star at the center of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light and infrared radiation with 10% at ultraviolet energies. ([Wikipedia](https://en.wikipedia.org/wiki/Sun)) <!-- REAL-GENERATIVE-MEDIA:END --> ## Navigation - Space Mining In Minnesota CoE · Technate Expansion · All 14 surveys - Centers of Excellence Portal ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Sun) : [Wikitube](https://en.wikitube.io/wiki/Sun) ## Previous hub tags Tree parents: [[Helium]] · [[Hydrogen]] · [[Oxygen]]. Legacy hubs: none. *Legacy media (later editing), kept in place under `Wikitube - Collision And Promoted Articles/Sun/`: `Sun Images` (1)* --- *Sources: 1 legacy note. Minted wave 1, 2026-07-30 (v1.6 order).*