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105-664: The venue opened on April 26, 1996. Since opening, the venue has gone through numerous name changes; it is the amphitheatre that has had the most name changes in the United States. It was initially named Coral Sky Amphitheatre because the seats face into the west, often in view of a colorful sunset . The venue was renamed to Mars Music Amphitheatre on January 6, 2000, named after the music store chain Mars Music . However, Mars Music filed for Chapter 11 bankruptcy in 2002, and in August 2002

210-476: A central subject for astronomical research since antiquity . The Sun orbits the Galactic Center at a distance of 24,000 to 28,000 light-years . From Earth, it is 1  astronomical unit ( 1.496 × 10  km ) or about 8 light-minutes away. Its diameter is about 1,391,400 km ( 864,600 mi ), 109 times that of Earth. Its mass is about 330,000 times that of Earth, making up about 99.86% of

315-561: A distance of one astronomical unit (AU) from the Sun (that is, at or near Earth's orbit). Sunlight on the surface of Earth is attenuated by Earth's atmosphere , so that less power arrives at the surface (closer to 1,000 W/m ) in clear conditions when the Sun is near the zenith . Sunlight at the top of Earth's atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light. The atmosphere filters out over 70% of solar ultraviolet, especially at

420-403: A fairly small amount of power being generated per cubic metre . Theoretical models of the Sun's interior indicate a maximum power density, or energy production, of approximately 276.5 watts per cubic metre at the center of the core, which, according to Karl Kruszelnicki , is about the same power density inside a compost pile . The fusion rate in the core is in a self-correcting equilibrium:

525-414: A few millimeters. Re-emission happens in a random direction and usually at slightly lower energy. With this sequence of emissions and absorptions, it takes a long time for radiation to reach the Sun's surface. Estimates of the photon travel time range between 10,000 and 170,000 years. In contrast, it takes only 2.3 seconds for neutrinos , which account for about 2% of the total energy production of

630-401: A granular appearance called the solar granulation at the smallest scale and supergranulation at larger scales. Turbulent convection in this outer part of the solar interior sustains "small-scale" dynamo action over the near-surface volume of the Sun. The Sun's thermal columns are Bénard cells and take the shape of roughly hexagonal prisms. The visible surface of the Sun, the photosphere,

735-542: A new sponsor. In June, the venue succeeded in securing a new sponsorship with Perfect Vodka, and it was renamed to the Perfect Vodka Amphitheatre at the South Florida Fairgrounds . Its name reverted again to Coral Sky Amphiteatre on August 4, 2017. On January 16, 2020, the name was changed to iTHINK Financial Amphitheatre , after a sponsorship deal with iTHINK Financial Credit Union . Because of

840-508: A period known as the Maunder minimum . This coincided in time with the era of the Little Ice Age , when Europe experienced unusually cold temperatures. Earlier extended minima have been discovered through analysis of tree rings and appear to have coincided with lower-than-average global temperatures. The temperature of the photosphere is approximately 6,000 K, whereas the temperature of

945-485: A phenomenon described by Hale's law . During the solar cycle's declining phase, energy shifts from the internal toroidal magnetic field to the external poloidal field, and sunspots diminish in number and size. At solar-cycle minimum, the toroidal field is, correspondingly, at minimum strength, sunspots are relatively rare, and the poloidal field is at its maximum strength. With the rise of the next 11-year sunspot cycle, differential rotation shifts magnetic energy back from

1050-473: A result, the outward-flowing solar wind stretches the interplanetary magnetic field outward, forcing it into a roughly radial structure. For a simple dipolar solar magnetic field, with opposite hemispherical polarities on either side of the solar magnetic equator, a thin current sheet is formed in the solar wind. At great distances, the rotation of the Sun twists the dipolar magnetic field and corresponding current sheet into an Archimedean spiral structure called

1155-410: A slightly higher rate of fusion would cause the core to heat up more and expand slightly against the weight of the outer layers, reducing the density and hence the fusion rate and correcting the perturbation ; and a slightly lower rate would cause the core to cool and shrink slightly, increasing the density and increasing the fusion rate and again reverting it to its present rate. The radiative zone

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1260-406: A transition layer, the tachocline . This is a region where the sharp regime change between the uniform rotation of the radiative zone and the differential rotation of the convection zone results in a large shear between the two—a condition where successive horizontal layers slide past one another. Presently, it is hypothesized that a magnetic dynamo, or solar dynamo , within this layer generates

1365-409: Is nautical twilight , between 6 and 12 degrees below the horizon. The third phase is astronomical twilight , which is the period when the Sun is between 12 and 18 degrees below the horizon. Dusk is at the very end of astronomical twilight, and is the darkest moment of twilight just before night . Finally, night occurs when the Sun reaches 18 degrees below the horizon and no longer illuminates

1470-639: Is by far the brightest object in the Earth's sky , with an apparent magnitude of −26.74. This is about 13 billion times brighter than the next brightest star, Sirius , which has an apparent magnitude of −1.46. One astronomical unit (about 150 million kilometres; 93 million miles) is defined as the mean distance between the centres of the Sun and the Earth. The instantaneous distance varies by about ± 2.5 million km or 1.55 million miles as Earth moves from perihelion on ~ January 3rd to aphelion on ~ July 4th. At its average distance, light travels from

1575-436: Is defined to begin at the distance where the flow of the solar wind becomes superalfvénic —that is, where the flow becomes faster than the speed of Alfvén waves, at approximately 20 solar radii ( 0.1 AU ). Turbulence and dynamic forces in the heliosphere cannot affect the shape of the solar corona within, because the information can only travel at the speed of Alfvén waves. The solar wind travels outward continuously through

1680-410: Is derived from the morpheme "ws" – meaning "up", and "chód" – signifying "move" (from the verb chodzić – meaning "walk, move"), due to the act of the Sun coming up from behind the horizon. The Polish word for west , zachód ( zakhud ), is similar but with the word "za" at the start, meaning "behind", from the act of the Sun going behind the horizon. In Russian , the word for west, запад ( zapad ),

1785-407: Is derived from the words за – meaning "behind", and пад – signifying "fall" (from the verb падать – padat' ), due to the act of the Sun falling behind the horizon. In Hebrew, the word for east is 'מזרח', which derives from the word for rising, and the word for west is 'מערב', which derives from the word for setting. The 16th-century astronomer Nicolaus Copernicus was the first to present to

1890-402: Is facilitated by the full ionization of helium in the transition region, which significantly reduces radiative cooling of the plasma. The transition region does not occur at a well-defined altitude, but forms a kind of nimbus around chromospheric features such as spicules and filaments , and is in constant, chaotic motion. The transition region is not easily visible from Earth's surface, but

1995-407: Is less than one degree. The time of sunset varies throughout the year and is determined by the viewer's position on Earth, specified by latitude and longitude , altitude , and time zone . Small daily changes and noticeable semi-annual changes in the timing of sunsets are driven by the axial tilt of the Earth , daily rotation of the Earth, the planet's movement in its annual elliptical orbit around

2100-461: Is not strongly wavelength-dependent. Mie scattering is responsible for the light scattered by clouds, and also for the daytime halo of white light around the Sun (forward scattering of white light). Sunset colors are typically more brilliant than sunrise colors, because the evening air contains more particles than morning air. Sometimes just before sunrise or after sunset a green flash can be seen. Ash from volcanic eruptions, trapped within

2205-409: Is only 84% of what it was in the protostellar phase (before nuclear fusion in the core started). In the future, helium will continue to accumulate in the core, and in about 5 billion years this gradual build-up will eventually cause the Sun to exit the main sequence and become a red giant . The chemical composition of the photosphere is normally considered representative of the composition of

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2310-441: Is readily observable from space by instruments sensitive to extreme ultraviolet . The corona is the next layer of the Sun. The low corona, near the surface of the Sun, has a particle density around 10  m to 10  m . The average temperature of the corona and solar wind is about 1,000,000–2,000,000 K; however, in the hottest regions it is 8,000,000–20,000,000 K. Although no complete theory yet exists to account for

2415-410: Is strongly attenuated by Earth's ozone layer , so that the amount of UV varies greatly with latitude and has been partially responsible for many biological adaptations, including variations in human skin color . High-energy gamma ray photons initially released with fusion reactions in the core are almost immediately absorbed by the solar plasma of the radiative zone, usually after traveling only

2520-477: Is suggested by a high abundance of heavy elements in the Solar System, such as gold and uranium , relative to the abundances of these elements in so-called Population II , heavy-element-poor, stars. The heavy elements could most plausibly have been produced by endothermic nuclear reactions during a supernova, or by transmutation through neutron absorption within a massive second-generation star. The Sun

2625-470: Is tens to hundreds of kilometers thick, and is slightly less opaque than air on Earth. Because the upper part of the photosphere is cooler than the lower part, an image of the Sun appears brighter in the center than on the edge or limb of the solar disk, in a phenomenon known as limb darkening . The spectrum of sunlight has approximately the spectrum of a black-body radiating at 5,772 K (9,930 °F), interspersed with atomic absorption lines from

2730-570: Is the disappearance of the Sun at then end of the Sun path , below the horizon of the Earth (or any other astronomical object in the Solar System ) due to its rotation . As viewed from everywhere on Earth, it is a phenomenon that happens approximately once every 24 hours, except in areas close to the poles . The equinox Sun sets due west at the moment of both the spring and autumn equinoxes. As viewed from

2835-437: Is the layer below which the Sun becomes opaque to visible light. Photons produced in this layer escape the Sun through the transparent solar atmosphere above it and become solar radiation, sunlight. The change in opacity is due to the decreasing amount of H ions , which absorb visible light easily. Conversely, the visible light perceived is produced as electrons react with hydrogen atoms to produce H ions. The photosphere

2940-424: Is the most prominent variation in which the number and size of sunspots waxes and wanes. The solar magnetic field extends well beyond the Sun itself. The electrically conducting solar wind plasma carries the Sun's magnetic field into space, forming what is called the interplanetary magnetic field . In an approximation known as ideal magnetohydrodynamics , plasma particles only move along magnetic field lines. As

3045-531: Is the only region of the Sun that produces an appreciable amount of thermal energy through fusion; 99% of the Sun's power is generated in the innermost 24% of its radius, and almost no fusion occurs beyond 30% of the radius. The rest of the Sun is heated by this energy as it is transferred outward through many successive layers, finally to the solar photosphere where it escapes into space through radiation (photons) or advection (massive particles). The proton–proton chain occurs around 9.2 × 10 times each second in

3150-420: Is the thickest layer of the Sun, at 0.45 solar radii. From the core out to about 0.7 solar radii , thermal radiation is the primary means of energy transfer. The temperature drops from approximately 7 million to 2 million kelvins with increasing distance from the core. This temperature gradient is less than the value of the adiabatic lapse rate and hence cannot drive convection, which explains why

3255-527: Is ultimately related to the word for sun in other branches of the Indo-European language family, though in most cases a nominative stem with an l is found, rather than the genitive stem in n , as for example in Latin sōl , ancient Greek ἥλιος ( hēlios ), Welsh haul and Czech slunce , as well as (with *l > r ) Sanskrit स्वर् ( svár ) and Persian خور ( xvar ). Indeed,

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3360-402: Is wave heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone. These waves travel upward and dissipate in the corona, depositing their energy in the ambient matter in the form of heat. The other is magnetic heating, in which magnetic energy is continuously built up by photospheric motion and released through magnetic reconnection in

3465-539: The Alfvén surface , the boundary separating the corona from the solar wind, defined as where the coronal plasma's Alfvén speed and the large-scale solar wind speed are equal. During the flyby, Parker Solar Probe passed into and out of the corona several times. This proved the predictions that the Alfvén critical surface is not shaped like a smooth ball, but has spikes and valleys that wrinkle its surface. The Sun emits light across

3570-577: The Northern Hemisphere , the Sun sets to the northwest (or not at all) in the spring and summer, and to the southwest in the autumn and winter; these seasons are reversed for the Southern Hemisphere . The time of actual sunset is defined in astronomy as two minutes before the upper limb of the Sun disappears below the horizon. Near the horizon, atmospheric refraction causes sunlight rays to be distorted to such an extent that geometrically

3675-520: The Parker spiral . Sunspots are visible as dark patches on the Sun's photosphere and correspond to concentrations of magnetic field where convective transport of heat is inhibited from the solar interior to the surface. As a result, sunspots are slightly cooler than the surrounding photosphere, so they appear dark. At a typical solar minimum , few sunspots are visible, and occasionally none can be seen at all. Those that do appear are at high solar latitudes. As

3780-436: The Southern Hemisphere , but with the respective dates reversed, with the earliest sunsets occurring some time before June 21 in winter, and the latest sunsets occurring some time after December 21 in summer, again depending on one's southern latitude. For a few weeks surrounding both solstices, both sunrise and sunset get slightly later each day. Even on the equator, sunrise and sunset shift several minutes back and forth through

3885-399: The azimuths of sunset on other dates are complex, but they can be estimated with reasonable accuracy by using the analemma. As sunrise and sunset are calculated from the leading and trailing edges of the Sun, respectively, and not the center, the duration of a daytime is slightly longer than nighttime (by about 10 minutes, as seen from temperate latitudes). Further, because the light from

3990-410: The corona , and the heliosphere . The coolest layer of the Sun is a temperature minimum region extending to about 500 km above the photosphere, and has a temperature of about 4,100  K . This part of the Sun is cool enough to allow for the existence of simple molecules such as carbon monoxide and water. The chromosphere, transition region, and corona are much hotter than the surface of

4095-531: The gravitational collapse of matter within a region of a large molecular cloud . Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System . The central mass became so hot and dense that it eventually initiated nuclear fusion in its core . Every second, the Sun's core fuses about 600 billion kilograms (kg) of hydrogen into helium and converts 4 billion kg of matter into energy . About 4 to 7 billion years from now, when hydrogen fusion in

4200-602: The l -stem survived in Proto-Germanic as well, as * sōwelan , which gave rise to Gothic sauil (alongside sunnō ) and Old Norse prosaic sól (alongside poetic sunna ), and through it the words for sun in the modern Scandinavian languages: Swedish and Danish sol , Icelandic sól , etc. The principal adjectives for the Sun in English are sunny for sunlight and, in technical contexts, solar ( / ˈ s oʊ l ər / ), from Latin sol . From

4305-428: The photosphere . For the purpose of measurement, the Sun's radius is considered to be the distance from its center to the edge of the photosphere, the apparent visible surface of the Sun. By this measure, the Sun is a near-perfect sphere with an oblateness estimated at 9 millionths, which means that its polar diameter differs from its equatorial diameter by only 10 kilometers (6.2 mi). The tidal effect of

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4410-446: 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. It is by far the most important source of energy for life on Earth . The Sun has been an object of veneration in many cultures. It has been

4515-495: The troposphere , tends to mute sunset and sunrise colors, while volcanic ejecta that is instead lofted into the stratosphere (as thin clouds of tiny sulfuric acid droplets), can yield beautiful post-sunset colors called afterglows and pre-sunrise glows. A number of eruptions, including those of Mount Pinatubo in 1991 and Krakatoa in 1883 , have produced sufficiently high stratus clouds containing sulfuric acid to yield remarkable sunset afterglows (and pre-sunrise glows) around

4620-444: The visible spectrum , so its color is white , with a CIE color-space index near (0.3, 0.3), when viewed from space or when the Sun is high in the sky. The Solar radiance per wavelength peaks in the green portion of the spectrum when viewed from space. When the Sun is very low in the sky, atmospheric scattering renders the Sun yellow, red, orange, or magenta, and in rare occasions even green or blue . Some cultures mentally picture

4725-488: The Earth's slower movement around the aphelion around July 4). Likewise, the earliest sunset does not occur on the winter solstice, but rather about two weeks earlier, again depending on the viewer's latitude. In the Northern Hemisphere, it occurs in early December or late November (influenced by the Earth's faster movement near its perihelion , which occurs around January 3). Likewise, the same phenomenon exists in

4830-461: The Greek helios comes the rare adjective heliac ( / ˈ h iː l i æ k / ). In English, the Greek and Latin words occur in poetry as personifications of the Sun, Helios ( / ˈ h iː l i ə s / ) and Sol ( / ˈ s ɒ l / ), while in science fiction Sol may be used to distinguish the Sun from other stars. The term sol with a lowercase s is used by planetary astronomers for

4935-537: The Palm Beaches' climate, many major concert tours that would visit arenas in other cities usually stop at iTHINK Financial Amphitheatre, enabling it to be used as a year-round concert venue. Other events include The Buzz Bake Sale , Curiosa , Lilith Fair , The Gigantour , Projekt Revolution , Christ Fellowship 's Easter services, Ozzfest , Crüe Fest , Crüe Fest 2 , The Mayhem Festival and The Vans Warped Tour , among others. On November 2, 1996, Phish played

5040-446: The Solar System . Long-term secular change in sunspot number is thought, by some scientists, to be correlated with long-term change in solar irradiance, which, in turn, might influence Earth's long-term climate. The solar cycle influences space weather conditions, including those surrounding Earth. For example, in the 17th century, the solar cycle appeared to have stopped entirely for several decades; few sunspots were observed during

5145-443: The Sun as yellow and some even red; the cultural reasons for this are debated. The Sun is classed as a G2 star, meaning it is a G-type star , with 2 indicating its surface temperature is in the second range of the G class. The solar constant is the amount of power that the Sun deposits per unit area that is directly exposed to sunlight. The solar constant is equal to approximately 1,368 W/m (watts per square meter) at

5250-475: The Sun does not rise or set for 24 hours or more, known as polar day and polar night . These phenomena occur due to Earth’s axial tilt , causing continuous sunlight or darkness at certain times of the year. Approximate locations of sunset on the horizon ( azimuth ) as described above can be found in Refs. The figure on the right is calculated using the solar geometry routine as follows: An interesting feature in

5355-424: The Sun extends from the center to about 20–25% of the solar radius. It has a density of up to 150 g/cm (about 150 times the density of water) and a temperature of close to 15.7 million kelvin (K). By contrast, the Sun's surface temperature is about 5800 K . Recent analysis of SOHO mission data favors the idea that the core is rotating faster than the radiative zone outside it. Through most of

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5460-408: The Sun is refracted as it passes through the Earth's atmosphere, the Sun is still visible after it is geometrically below the horizon. Refraction also affects the apparent shape of the Sun when it is very close to the horizon. It makes things appear higher in the sky than they really are. Light from the bottom edge of the Sun's disk is refracted more than light from the top, since refraction increases as

5565-688: The Sun will shed its outer layers and become a dense type of cooling star (a white dwarf ), and no longer produce energy by fusion, but will still glow and give off heat from its previous fusion for perhaps trillions of years. After that, it is theorized to become a super dense black dwarf , giving off negligible energy. The English word sun developed from Old English sunne . Cognates appear in other Germanic languages , including West Frisian sinne , Dutch zon , Low German Sünn , Standard German Sonne , Bavarian Sunna , Old Norse sunna , and Gothic sunnō . All these words stem from Proto-Germanic * sunnōn . This

5670-413: The Sun's magnetic field . The Sun's convection zone extends from 0.7 solar radii (500,000 km) to near the surface. In this layer, the solar plasma is not dense or hot enough to transfer the heat energy of the interior outward via radiation. Instead, the density of the plasma is low enough to allow convective currents to develop and move the Sun's energy outward towards its surface. Material heated at

5775-398: The Sun's core by radiation rather than by convection (see Radiative zone below), so the fusion products are not lifted outward by heat; they remain in the core, and gradually an inner core of helium has begun to form that cannot be fused because presently the Sun's core is not hot or dense enough to fuse helium. In the current photosphere, the helium fraction is reduced, and the metallicity

5880-426: The Sun's core diminishes to the point where the Sun is no longer in hydrostatic equilibrium , its core will undergo a marked increase in density and temperature which will cause its outer layers to expand, eventually transforming the Sun into a red giant . This process will make the Sun large enough to render Earth uninhabitable approximately five billion years from the present. After the red giant phase, models suggest

5985-403: The Sun's horizon to Earth's horizon in about 8 minutes and 20 seconds, while light from the closest points of the Sun and Earth takes about two seconds less. The energy of this sunlight supports almost all life on Earth by photosynthesis , and drives Earth's climate and weather. The Sun does not have a definite boundary, but its density decreases exponentially with increasing height above

6090-493: The Sun's life, energy has been produced by nuclear fusion in the core region through the proton–proton chain ; this process converts hydrogen into helium. Currently, 0.8% of the energy generated in the Sun comes from another sequence of fusion reactions called the CNO cycle ; the proportion coming from the CNO cycle is expected to increase as the Sun becomes older and more luminous. The core

6195-551: The Sun's life, they account for 74.9% and 23.8%, respectively, of the mass of the Sun in the photosphere. All heavier elements, called metals in astronomy, account for less than 2% of the mass, with oxygen (roughly 1% of the Sun's mass), carbon (0.3%), neon (0.2%), and iron (0.2%) being the most abundant. The Sun's original chemical composition was inherited from the interstellar medium out of which it formed. Originally it would have been about 71.1% hydrogen, 27.4% helium, and 1.5% heavier elements. The hydrogen and most of

6300-462: The Sun, and the Earth and Moon's paired revolutions around each other. During winter and spring, the days get longer and sunsets occur later every day until the day of the latest sunset, which occurs after the summer solstice. In the Northern Hemisphere , the latest sunset occurs late in June or in early July, but not on the summer solstice of June 21. This date depends on the viewer's latitude (connected with

6405-438: The Sun, to reach the surface. Because energy transport in the Sun is a process that involves photons in thermodynamic equilibrium with matter , the time scale of energy transport in the Sun is longer, on the order of 30,000,000 years. This is the time it would take the Sun to return to a stable state if the rate of energy generation in its core were suddenly changed. Electron neutrinos are released by fusion reactions in

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6510-402: The Sun. The reason is not well understood, but evidence suggests that Alfvén waves may have enough energy to heat the corona. Above the temperature minimum layer is a layer about 2,000 km thick, dominated by a spectrum of emission and absorption lines. It is called the chromosphere from the Greek root chroma , meaning color, because the chromosphere is visible as a colored flash at

6615-401: The air is full of red dust , blown into the atmosphere by high winds, so its sky color is mainly determined by a Mie Scattering process, resulting in more blue hues than an Earth sunset. One study also reported that Martian dust high in the atmosphere can reflect sunlight up to two hours after the Sun has set, casting a diffuse glow across the surface of Mars. Sun The Sun is

6720-670: The amphitheatre as part of their 1996 fall tour. They were joined by Karl Perazzo (of Santana fame) on percussion for the entire show. Portions of this performance were released to the syndicated radio program The Album Network. This show was released as the Coral Sky DVD in 2010 and is available as a download from LivePhish. On June 15, 1998, the Spice Girls kicked off the US leg of the Spiceworld Tour ; two weeks prior, Geri Halliwell had left

6825-498: The angle of elevation decreases. This raises the apparent position of the bottom edge more than the top, reducing the apparent height of the solar disk. Its width is unaltered, so the disk appears wider than it is high. (In reality, the Sun is almost exactly spherical.) The Sun also appears larger on the horizon, an optical illusion, similar to the moon illusion . Locations within the Arctic and Antarctic Circles experience periods where

6930-486: The beginning and end of total solar eclipses. The temperature of the chromosphere increases gradually with altitude, ranging up to around 20,000 K near the top. In the upper part of the chromosphere helium becomes partially ionized . Above the chromosphere, in a thin (about 200 km ) transition region, the temperature rises rapidly from around 20,000 K in the upper chromosphere to coronal temperatures closer to 1,000,000 K . The temperature increase

7035-436: The compass bear names etymologically derived from words for sunrise and sunset. The English words " orient " and " occident ", meaning "east" and "west", respectively, are descended from Latin words meaning "sunrise" and "sunset". The word "levant", related e.g. to French " (se) lever " meaning "lift" or "rise" (and also to English "elevate"), is also used to describe the east. In Polish , the word for east wschód ( vskhud ),

7140-460: The core, but, unlike photons, they rarely interact with matter, so almost all are able to escape the Sun immediately. However, measurements of the number of these neutrinos produced in the Sun are lower than theories predict by a factor of 3. In 2001, the discovery of neutrino oscillation resolved the discrepancy: the Sun emits the number of electron neutrinos predicted by the theory, but neutrino detectors were missing 2 ⁄ 3 of them because

7245-495: The core, converting about 3.7 × 10 protons into alpha particles (helium nuclei) every second (out of a total of ~8.9 × 10 free protons in the Sun), or about 6.2 × 10  kg/s . However, each proton (on average) takes around 9 billion years to fuse with another using the PP chain. Fusing four free protons (hydrogen nuclei) into a single alpha particle (helium nucleus) releases around 0.7% of

7350-401: The corona reaches 1,000,000–2,000,000 K . The high temperature of the corona shows that it is heated by something other than direct heat conduction from the photosphere. It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating. The first

7455-400: The duration of a solar day on another planet such as Mars . The astronomical symbol for the Sun is a circle with a center dot, [REDACTED] . It is used for such units as M ☉ ( Solar mass ), R ☉ ( Solar radius ) and L ☉ ( Solar luminosity ). The scientific study of the Sun is called heliology . The Sun is a G-type main-sequence star that makes up about 99.86% of

7560-563: The external poloidal dipolar magnetic field is near its dynamo-cycle minimum strength; but an internal toroidal quadrupolar field, generated through differential rotation within the tachocline, is near its maximum strength. At this point in the dynamo cycle, buoyant upwelling within the convective zone forces emergence of the toroidal magnetic field through the photosphere, giving rise to pairs of sunspots, roughly aligned east–west and having footprints with opposite magnetic polarities. The magnetic polarity of sunspot pairs alternates every solar cycle,

7665-492: The figure on the right is apparent hemispheric symmetry in regions where daily sunrise and sunset actually occur. This symmetry becomes clear if the hemispheric relation in sunrise equation is applied to the x- and y-components of the solar vector presented in Ref. As a ray of white sunlight travels through the atmosphere to an observer, some of the colors are scattered out of the beam by air molecules and airborne particles , changing

7770-520: The final color of the beam the viewer sees. Because the shorter wavelength components, such as blue and green, scatter more strongly, these colors are preferentially removed from the beam. At sunrise and sunset, when the path through the atmosphere is longer, the blue and green components are removed almost completely, leaving the longer wavelength orange and red hues we see at those times. The remaining reddened sunlight can then be scattered by cloud droplets and other relatively large particles to light up

7875-572: The first time. May 20, 2017 the band Muse played there along with 30 Seconds to Mars and Pvris . May 27, 2017 the band Train played at the amphitheater for their "Play that song" world tour, along with Natasha Bedingfield and O.A.R. Since 1996 Dave Matthews Band has performed at the amphitheater more than 30 times, playing two-night stands at the venue nearly each year, beginning in 2002. 26°41′07″N 80°11′11″W  /  26.685387°N 80.186269°W  / 26.685387; -80.186269 Sunset Sunset (or sundown )

7980-404: The fused mass as energy, so the Sun releases energy at the mass–energy conversion rate of 4.26 billion kg/s (which requires 600 billion kg of hydrogen ), for 384.6  yottawatts ( 3.846 × 10  W ), or 9.192 × 10   megatons of TNT per second. The large power output of the Sun is mainly due to the huge size and density of its core (compared to Earth and objects on Earth), with only

8085-531: The group. On September 4, 2003 Tori Amos played her last concert of her Scarlet's Walk tour here. It was filmed and released on DVD one year later, in May 2004, called Welcome to Sunny Florida . The venue was scheduled to host the final Ozzfest tour date of 2004, on September 4, but the show was cancelled due to Hurricane Frances . On June 16, 2015 Lana Del Rey played her last concert of The Endless Summer Tour performing songs like Honeymoon and Florida Kilos for

8190-477: The heliosphere, forming the solar magnetic field into a spiral shape, until it impacts the heliopause more than 50 AU from the Sun. In December 2004, the Voyager 1 probe passed through a shock front that is thought to be part of the heliopause. In late 2012, Voyager 1 recorded a marked increase in cosmic ray collisions and a sharp drop in lower energy particles from the solar wind, which suggested that

8295-432: The helium in the Sun would have been produced by Big Bang nucleosynthesis in the first 20 minutes of the universe, and the heavier elements were produced by previous generations of stars before the Sun was formed, and spread into the interstellar medium during the final stages of stellar life and by events such as supernovae . Since the Sun formed, the main fusion process has involved fusing hydrogen into helium. Over

8400-402: The horizon red and orange. The removal of the shorter wavelengths of light is due to Rayleigh scattering by air molecules and particles much smaller than the wavelength of visible light (less than 50 nm in diameter). The scattering by cloud droplets and other particles with diameters comparable to or larger than the sunlight's wavelengths (> 600 nm) is due to Mie scattering and

8505-500: The mass of the Solar System. It has an absolute magnitude of +4.83, estimated to be brighter than about 85% of the stars in the Milky Way , most of which are red dwarfs . It is more massive than 95% of the stars within 7 pc (23 ly). The Sun is a Population I , or heavy-element-rich, star. Its formation approximately 4.6 billion years ago may have been triggered by shockwaves from one or more nearby supernovae . This

8610-444: The neutrinos had changed flavor by the time they were detected. The Sun has a stellar magnetic field that varies across its surface. Its polar field is 1–2 gauss (0.0001–0.0002  T ), whereas the field is typically 3,000 gauss (0.3 T) in features on the Sun called sunspots and 10–100 gauss (0.001–0.01 T) in solar prominences . The magnetic field varies in time and location. The quasi-periodic 11-year solar cycle

8715-419: The past 4.6 billion years, the amount of helium and its location within the Sun has gradually changed. The proportion of helium within the core has increased from about 24% to about 60% due to fusion, and some of the helium and heavy elements have settled from the photosphere toward the center of the Sun because of gravity . The proportions of heavier elements are unchanged. Heat is transferred outward from

8820-414: The photospheric surface. Both coronal mass ejections and high-speed streams of solar wind carry plasma and the interplanetary magnetic field outward into the Solar System. The effects of solar activity on Earth include auroras at moderate to high latitudes and the disruption of radio communications and electric power . Solar activity is thought to have played a large role in the formation and evolution of

8925-450: The planets is weak and does not significantly affect the shape of the Sun. The Sun rotates faster at its equator than at its poles . This differential rotation is caused by convective motion due to heat transport and the Coriolis force due to the Sun's rotation. In a frame of reference defined by the stars, the rotational period is approximately 25.6 days at the equator and 33.5 days at

9030-473: The poles. Viewed from Earth as it orbits the Sun, the apparent rotational period of the Sun at its equator is about 28 days. Viewed from a vantage point above its north pole, the Sun rotates counterclockwise around its axis of spin. A survey of solar analogs suggest the early Sun was rotating up to ten times faster than it does today. This would have made the surface much more active, with greater X-ray and UV emission. Sun spots would have covered 5–30% of

9135-557: The poloidal to the toroidal field, but with a polarity that is opposite to the previous cycle. The process carries on continuously, and in an idealized, simplified scenario, each 11-year sunspot cycle corresponds to a change, then, in the overall polarity of the Sun's large-scale magnetic field. The Sun's magnetic field leads to many effects that are collectively called solar activity . Solar flares and coronal mass ejections tend to occur at sunspot groups. Slowly changing high-speed streams of solar wind are emitted from coronal holes at

9240-448: The primordial Solar System. Typically, the solar heavy-element abundances described above are measured both by using spectroscopy of the Sun's photosphere and by measuring abundances in meteorites that have never been heated to melting temperatures. These meteorites are thought to retain the composition of the protostellar Sun and are thus not affected by the settling of heavy elements. The two methods generally agree well. The core of

9345-470: The probe had passed through the heliopause and entered the interstellar medium , and indeed did so on August 25, 2012, at approximately 122 astronomical units (18 Tm) from the Sun. The heliosphere has a heliotail which stretches out behind it due to the Sun's peculiar motion through the galaxy. On April 28, 2021, NASA's Parker Solar Probe encountered the specific magnetic and particle conditions at 18.8 solar radii that indicated that it penetrated

9450-437: The shorter wavelengths. Solar ultraviolet radiation ionizes Earth's dayside upper atmosphere, creating the electrically conducting ionosphere . Ultraviolet light from the Sun has antiseptic properties and can be used to sanitize tools and water. This radiation causes sunburn , and has other biological effects such as the production of vitamin D and sun tanning . It is the main cause of skin cancer . Ultraviolet light

9555-484: The size it does from Earth , due to the greater distance between Mars and the Sun. The colors are typically hues of blue, but some Martian sunsets last significantly longer and appear far redder than is typical on Earth. The colors of the Martian sunset differ from those on Earth. Mars has a thin atmosphere , lacking oxygen and nitrogen , so the light scattering is not dominated by a Rayleigh Scattering process. Instead,

9660-566: The sky. Locations further north than the Arctic Circle and further south than the Antarctic Circle experience no full sunset or sunrise on at least one day of the year, when the polar day or the polar night persists continuously for 24 hours. At latitudes greater than within half a degree of either pole, the sun cannot rise or set on the same date on any day of the year, since the sun's angular elevation between solar noon and midnight

9765-425: The solar cycle progresses toward its maximum , sunspots tend to form closer to the solar equator, a phenomenon known as Spörer's law . The largest sunspots can be tens of thousands of kilometers across. An 11-year sunspot cycle is half of a 22-year Babcock –Leighton dynamo cycle, which corresponds to an oscillatory exchange of energy between toroidal and poloidal solar magnetic fields. At solar-cycle maximum,

9870-414: The solar disk is already about one diameter below the horizon when a sunset is observed. Sunset is distinct from twilight , which is divided into three stages. The first one is civil twilight , which begins once the Sun has disappeared below the horizon, and continues until it descends to 6 degrees below the horizon. The early to intermediate stages of twilight coincide with predusk . The second phase

9975-417: The surface. The rotation rate was gradually slowed by magnetic braking , as the Sun's magnetic field interacted with the outflowing solar wind. A vestige of this rapid primordial rotation still survives at the Sun's core, which has been found to be rotating at a rate of once per week; four times the mean surface rotation rate. The Sun consists mainly of the elements hydrogen and helium . At this time in

10080-431: The tachocline picks up heat and expands, thereby reducing its density and allowing it to rise. As a result, an orderly motion of the mass develops into thermal cells that carry most of the heat outward to the Sun's photosphere above. Once the material diffusively and radiatively cools just beneath the photospheric surface, its density increases, and it sinks to the base of the convection zone, where it again picks up heat from

10185-424: The temperature of the corona, at least some of its heat is known to be from magnetic reconnection . The corona is the extended atmosphere of the Sun, which has a volume much larger than the volume enclosed by the Sun's photosphere. A flow of plasma outward from the Sun into interplanetary space is the solar wind . The heliosphere, the tenuous outermost atmosphere of the Sun, is filled with solar wind plasma and

10290-422: The tenuous layers above the photosphere. The photosphere has a particle density of ~10  m (about 0.37% of the particle number per volume of Earth's atmosphere at sea level). The photosphere is not fully ionized—the extent of ionization is about 3%, leaving almost all of the hydrogen in atomic form. The Sun's atmosphere is composed of five layers: the photosphere, the chromosphere , the transition region ,

10395-404: The top of the radiative zone and the convective cycle continues. At the photosphere, the temperature has dropped 350-fold to 5,700 K (9,800 °F) and the density to only 0.2 g/m (about 1/10,000 the density of air at sea level, and 1 millionth that of the inner layer of the convective zone). The thermal columns of the convection zone form an imprint on the surface of the Sun giving it

10500-424: The total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen , carbon , neon , and iron . The Sun is a G-type main-sequence star (G2V), informally called a yellow dwarf , though its light is actually white. It formed approximately 4.6 billion years ago from

10605-418: The transfer of energy through this zone is by radiation instead of thermal convection. Ions of hydrogen and helium emit photons, which travel only a brief distance before being reabsorbed by other ions. The density drops a hundredfold (from 20 000 kg/m to 200 kg/m ) between 0.25 solar radii and 0.7 radii, the top of the radiative zone. The radiative zone and the convective zone are separated by

10710-565: The venue reverted to its previous name. It then changed again when Sound Advice became the new sponsor, and was renamed Sound Advice Amphitheatre on June 1, 2003. In early 2008, the venue was renamed again following a new sponsorship agreement with Cruzan Rum , becoming the Cruzan Amphitheatre on February 1, 2008. On February 11, 2015, the venue reverted to its original name, the Coral Sky Amphitheatre , while owners looked for

10815-438: The world a detailed and eventually widely accepted mathematical model supporting the premise that the Earth is moving and the Sun actually stays still, despite the impression from our point of view of a moving Sun. Sunsets on other planets appear different because of differences in the distance of the planet from the Sun and non-existent or differing atmospheric compositions. On Mars , the setting Sun appears about two-thirds

10920-442: The world. The high-altitude clouds serve to reflect strongly reddened sunlight still striking the stratosphere after sunset, down to the surface. Some of the most varied colors at sunset can be found in the opposite or eastern sky after the Sun has set during twilight. Depending on weather conditions and the types of clouds present, these colors have a wide spectrum, and can produce unusual results. In some languages, points of

11025-652: The year, along with solar noon. These effects are plotted by an analemma . Neglecting atmospheric refraction and the Sun's non-zero size, whenever and wherever sunset occurs, it is always in the northwest quadrant from the March equinox to the September equinox , and in the southwest quadrant from the September equinox to the March equinox. Sunsets occur almost exactly due west on the equinoxes for all viewers on Earth. Exact calculations of

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