SUN

#REDIRECT Sun_Microsystems

Sun

:: ''For the astrological significance of the Sun, see Solar system in astrology.'' :''"Solar" redirects here; for the superhero by that name, see Solar (comics).'' {| border="2" cellpadding="4" cellspacing="0" style="margin: 0 0 1em 1em; border: 1px #aaa solid; border-collapse: collapse;" align="right" width=280px |+ |+ The Sun |- | colspan="2" align="center" | |- ! bgcolor="#ffffc0" colspan="2" align="center" | Observation data |- ! align="left" | Mean distance from
Earth | 1 E11 m×10⁶ kilometre
(92.95×10⁶ mile)
(8.31 minutes at the Speed of Light) |- ! align="left" | Apparent magnitude (''V'') | −26.8^m |- ! align="left" | Absolute magnitude | 4.8^m |- ! bgcolor="#ffffc0" colspan="2" align="center" | Orbital characteristics |- ! align="left" | Mean distance from
Milky Way core | 2.5×10¹⁷ km
(26,000 light-years) |- ! align="left" | Galaxy period | 2.26×10⁸ Julian year |- ! align="left" | Velocity | 217 km/second |- ! bgcolor="#ffffc0" colspan="2" align="center" | Physical characteristics |- ! align="left" | Diameter | 1 E9 m×10⁶ km
(109 Earths) |- ! align="left" | Oblateness | 9×10^-6 |- ! align="left" | Surface area | 1 E18 m² scientific notation 10¹² square kilometre
(11,900 Earths) |- ! align="left" | Volume | 1 E27 m³ × 10¹⁸ cubic kilometre
(1,300,000 Earths) |- ! align="left" | Mass | 1 E30 kg × 10³⁰ kilogram
(332,950 Earths) |- ! align="left" | Density | 1.408 g/cm³ |- ! align="left" | Surface gravity | 273.95 m s^-2
(27.9 gee) |- ! align="left" | Escape velocity
from the surface | 617.54 km/s |- ! align="left" | Surface temperature | 5780 kelvin |- ! align="left" | Temperature of corona | 5 MegaK |- ! align="left" | Core temperature | ~13.6 MK |- ! align="left" | Luminosity (''L_☉'') | 3.827×10²⁶ watt |- ! align="left" | Mean Intensity (''I_☉'') | 2.009×10⁷ W m^-2 sr^-1 |- ! bgcolor="#ffffc0" colspan="2" align="center" | Rotation characteristics |- ! align="left" | Obliquity | 7.25degree (angle)
(to the ecliptic)
67.23?
(to the Milky Way) |- ! align="left" | Right ascension
of North pole ^{[http://www.hnsky.org/iau-iag.htm 1]} | 286.13?
(19 h 4 min 31.2 s) |- ! align="left" | Declination
of North pole | 63.87? |- ! align="left" | Solar rotation
at equator | 25.3800 days
(25 d 9 h 7 min 12?8 s) [http://www.hnsky.org/iau-iag.htm ¹] |- ! align="left" | Rotation velocity
at equator | 7174 km/h |- ! bgcolor="#ffffc0" colspan="2" align="center" | photosphere composition |- ! align="left" | Hydrogen | 73.46 % |- ! align="left" | Helium | 24.85 % |- ! align="left" | Oxygen | 0.77 % |- ! align="left" | Carbon | 0.29 % |- ! align="left" | Iron | 0.16 % |- ! align="left" | Neon | 0.12 % |- ! align="left" | Nitrogen | 0.09 % |- ! align="left" | Silicon | 0.07 % |- ! align="left" | Magnesium | 0.05 % |- ! align="left" | Sulfur | 0.04 % |} A sun is the star at the center of a solar system. Our sun is usually referred to as ''the'' Sun, and is occasionally referred to as Sol to distinguish it from other "suns". Planet Earth orbits the Sun, as do innumerable other bodies including other planets, asteroids, meteoroids, comets and dust. The primary stellar body around which an object orbits is called ''its'' sun, and stars in a multiple star system are referred to as the "suns" of bodies in that system. ==General information== The Sun is a main sequence star, with a Stellar_classification of G2, meaning that it is somewhat more massive and hotter than the average star but far smaller than a blue giant star. A G2 star is on the main sequence, and has a lifetime of about 10 billion years (10 GigaJulian year), and the Sun formed about 5 Ga (5 billion years) ago, as determined by nucleocosmochronology and computer models of stellar evolution. The Sun orbits the center of the Milky Way galaxy at a distance of about 25,000 to 28,000 light-years from the galactic centre, completing one revolution in about 1 E15 s (226 million years). The orbital speed is 217 km/s, i.e. 1 light-year in ca. 1400 years, and 1 AU in 8 days. The Astronomical symbols for the Sun is a circle with a point at its centre (☉). '''Caution: Looking directly at the Sun can damage the retina and one's eyesight.''' #Sun_and_eye_damage. ==Structure of the Sun== The Sun is a near-perfect sphere, with an oblateness estimated at about 9 millionths, which means the polar diameter differs from the equatorial by 10 km at most. This is because the centrifugal effect of the Sun's rather sedate Solar rotation is 18 million times weaker than its surface gravity (at the equator). Tidal effects from the planets do not significantly affect the shape of the Sun, although the Sun itself orbits the barycenter of the solar system, which is offset from the center of the Sun mostly because of the large mass of Jupiter (planet). The Sun does not have definite boundaries as rocky planets do. Instead, the density of gases comprising the Sun drops off following an Exponential_distribution relationship with distance from the centre of the Sun. Nevertheless, the Sun has well defined interior structure, described below. The Sun's radius is measured from centre to the edges of the photosphere. The solar interior is not accessible directly and the Sun itself is opaque to electromagnetic radiation. Humanity's knowledge of the solar interior comes from a combination of analytic modeling and computer modeling of stars, and helioseismology, the study of sound waves that travel through the Sun's interior. ===Core=== At the centre of the Sun, where its density is 150 g/cm³ (that's 150 times the density of water on Earth), thermonuclear reactions (nuclear fusion) convert hydrogen into helium, producing the heat that drives the entire star. About 8.9×10³⁷ proton (hydrogen nuclei) are converted to helium nuclei every second. This releases energy at the matter-energy conversion rate of 4.26 million tonnes per second or 383 SI prefix (9.15×10¹⁶ tons of Trinitrotoluene per second) which makes its way through the other layers of the Sun to escape in the form of electromagnetic radiation (sunshine) and neutrinos (and to a smaller extent as the kinetic energy and thermal energy of solar wind plasma and as the energy in the Sun's magnetic field). A fusion reactor, which some physicists believe may one day provide power for human use, would use a similar process to extract atomic energy. The core is the only part of the Sun where an appreciable amount of heat is produced by fusion: the rest of the star is heated by energy that is transferred outward. All of the energy of the interior fusion must travel through the successive layers to the solar photosphere, before it escapes to space. The core extends from the center to about 0.2 solar radius. ===Radiative zone=== From about 0.2 to about 0.7 solar radii, the material is hot and dense enough that thermal radiation is sufficient to transfer the intense heat of the core outward. In this zone, there is no thermal convection: while the material grows cooler with altitude, this gradient in temperature is not strong enough to drive convection. Heat is transferred by ions of hydrogen and helium emitting photons, which travel a brief distance before being re-absorbed by other ions. ===Convection zone=== From about 0.7 solar radii to 1.0 solar radii, the material in the Sun is neither dense nor hot enough to transfer the heat energy of the interior outward. As a result, convection carries the heat to the surface as thermal carry hot material to the surface (photosphere) of the Sun. Once the material cools off at the surface, it plunges back downward to the base of the convection zone, to receive more heat from the top of the radiative zone. There is a bit of convective overshoot at the base of the convection zone, carrying turbulent downflows into the top layers of the radiative zone. The thermal columns in the convection zone form an imprint on the surface of the Sun, in the form of the solar granulation and supergranulation. The turbulent convection of this outer part of the solar interior gives rise to a 'small-scale' dynamo that produces magnetic north and south poles all over the surface of the Sun. ===Photosphere=== The visible surface of the Sun, the photosphere, is the layer below which the Sun becomes opaque to visible light. Above the photosphere, sunlight is free to propagate into space and its energy escapes the Sun entirely. Sunlight has a black-body spectrum that is characteristic of about 6,000 kelvins, interspersed with atomic absorption line from the tenuous layers above the photosphere. The photosphere has a particle density of about 10²³/m³ (this is about 1% of the particle density of Earth's atmosphere at sea level). The parts of the Sun above the photosphere are referred to collectively as the ''solar atmosphere''. They can be viewed with telescopes operating across the electromagnetic spectrum, from radio through visible light to gamma rays. ===Temperature minimum=== The coolest layer of the Sun is the temperature minimum region about 500km above the photosphere. It is about 4,000 kelvins. It is the only part of the Sun cool enough to support simple molecules such as carbon monoxide and water; all other parts of the Sun are hot enough to break chemical bonds. ===Chromosphere=== Above the visible surface of the Sun is a thin layer, about 2,000 km thick, that is dominated by a spectrum of emission and absorption lines. It is called the ''chromosphere'' from the Greek root ''chromos'', meaning color, because the chromosphere is visible as a colored flash at the beginning and end of solar eclipse. ===Corona=== The corona is the extended outer atmosphere of the Sun, which is much larger than the Sun itself. The corona merges smoothly with the solar wind that fills the solar system and heliosphere. The low corona, near the surface of the Sun, has a particle density of 10¹¹/m³. ==Solar neutrino problem== For some time it was thought that the number of neutrinos produced by the nuclear reactions in the Sun was only one third of the number predicted by theory, a result that was termed the solar neutrino problem. Several neutrino observatories were created including the Sudbury Neutrino Observatory to try and measure the amount of neutrinos given off by the Sun. From these observatories and experiments it was recently found that neutrinos had rest mass, and could therefore transform into harder-to-detect varieties of neutrinos while en route from the Sun to Earth; thus measurement and theory were reconciled. [[Image:High_Resolution_Solar_Spectrum.jpg|thumb|left|Extremely high resolution spectrum of the Sun showing thousands of elemental absorption lines (fraunhofer lines).]] ==Magnetic field== All matter in the Sun is in the form of plasma due to its extreme temperature. This makes it possible for the Sun to rotate faster at its equator (about 25 days) than it does at higher latitudes (28 days near its poles). The solar rotation of the Sun's latitudes causes its magnetic field lines to become twisted together over time, causing magnetic field loops to erupt from the Sun's surface and trigger the formation of the Sun's dramatic sunspots and solar prominences. (See magnetic reconnection) The solar activity cycle includes old magnetic fields being stripped off the Sun's surface starting from one pole and ending at the other. The magnetic field of the sun reverses once for each 11-year sunspot cycle. ==Calculating the position of the Sun== Since the path of the sun across the sky varies throughout the year, a completely automatic heliostat, or sun tracker, must be guided by continuous calculations. The National Renewable Energy Laboratory has released its [http://rredc.nrel.gov/solar/codesandalgorithms/spa/ Solar Position Algorithm] (SPA) with [http://www.nrel.gov/docs/fy04osti/34302.pdf complete documentation]. Another resource is the [http://libnova.sourceforge.net/index.html libnova] ''Celestial Mechanics and Astronomical Calculation Library'', which also calculates variables such as apparent position and rise, set and transit times among many others of astronomical objects. == Solar space missions == To obtain an uninterrupted view of the Sun, the European Space Agency and NASA cooperatively launched the Solar and Heliospheric Observatory (SOHO) on December 2, 1995. Elemental abundances in the photosphere are well known from astronomical spectroscopy studies, but the composition of the interior of the Sun is much less well known. A solar wind sample return mission, Genesis (spacecraft), was designed to allow astronomers to directly measure the composition of solar material. It returned to Earth in 2004 and is undergoing analysis, but it was damaged by crash-landing when its parachute failed to deploy on reentry to Earth's atmosphere. [[Image:SOHO_solar_flare_sun_large_20031026_0119_eit_304.png|thumb|left|Large solar flare recorded by Solar and Heliospheric Observatory EIT304 instrument in the ultraviolet. (media:SOHO_solar_flare_sun_MPEG_20031026_eit_304.mpeg).]] ==History and future of the Sun== The Sun is thought to be a second-generation star, perhaps formed from some of the remains of a previous supernova. The evidence is mainly a high abundance of heavy elements such as iron, gold, and even uranium in the solar system: the most plausible ways that these elements could be produced is by nucleosynthesis inside a large, hot star. Our Sun does not have enough mass to explode as a supernova. Instead, in 4-5 billion years it will enter its red giant phase, expanding as the hydrogen fuel in the core is consumed. Then it will start to fuse helium and the core temperature will rise to 3×10⁸ K. While it is likely that the expansion of the outer layers of the Sun will reach the current position of Earth's orbit, recent research suggests that mass lost from the Sun earlier in its red giant phase will cause the Earth's orbit to move further out, preventing it from being engulfed. Following the red giant phase, giant thermal pulsations will cause the Sun to throw off its outer layers forming a planetary nebula. The Sun will then become a white dwarf, slowly cooling over eons. This stellar evolution is typical of small stars: our Sun appears to be a fairly run-of-the-mill star. ==Human understanding of the Sun== In many prehistoric and ancient cultures, the Sun was thought to be a solar deity or other supernatural phenomenon. One of the first people in the Western world to offer a scientific explanation for the sun was the Ancient Greece philosopher Anaxagoras, who reasoned that it was a giant flaming ball of rock or metal, and not the chariot of Apollo. For teaching this heresy he was imprisoned by the authorities and capital punishment. ==Sun and eye damage== Sunlight is quite bright and looking directly at the Sun is painful to the eyes. Looking directly at the Sun when it is high in the sky causes temporary bleaching of the photosensitive pigments in the retina, which makes phosphene visual artifacts and ''temporary'' partial blindness. Direct viewing of the Sun with the naked eye delivers about 4 milliwatts of sunlight to the retina that is in the solar image, heating it up and potentially (though not normally) damaging it. Brief viewing of the direct Sun with the naked eye is unpleasant but generally safe. Long-term exposure of the eyes to direct sunlight contributes to the normal UV-induced yellowing of the lens and cornea over periods of decades, and could play a part in the formation of cataracts. Viewing the Sun through light-concentrating optics such as binoculars is hazardous without an attenuating filter to dim the sunlight. Suitable filters are available at welding supply shops and camera stores. Viewing the Sun through unfiltered 7x50mm binoculars can deliver as much as 2.5 ''watts'' of sunlight into each eye, over 300 times more power than naked eye viewing. Even brief glances at the Sun through binoculars can cause permanent blindness. During eclipse of the Sun, another hazardous condition exists because of the way that the eye responds to bright light. The pupil is controlled by the total amount of light in the visual field, ''not'' by the brightest object in the field. During partial eclipses, most sunlight is blocked by the Moon passing directly in front of the Sun, but the uncovered parts of the photosphere have the same surface brightness as during a normal day. In the dim overall light, the pupil tends to dilate from ~2mm to perhaps 6mm diameter, increasing the eye's collecting area by a factor of nearly 10. Each retinal cell that is exposed to the partially-eclipsed solar image thus receives about ''ten times'' as much light as it would looking at the normal, non-eclipsed Sun. This can cause permanent localized damage to the retina, resulting in small, permanent blind spots for the viewer. This is an especially insidious hazard for inexperienced observers and for children, because there is no immediate perception of pain and it is tempting to stare at the spectacle of the eclipsing Sun. ==See also== {| |- valign=top | width=210 align=left | * Chromosphere * Corona * Coronal mass ejection * Faculae * Granule (solar physics)s * Helioseismology * Limb darkening * Magnetic reconnection * Photosphere * Solar flares * Solar neutrino problem | width=210 align=left | * Solar prominences ** Quiescent prominences ** Eruptive prominences ** Spicule (solar physics)s * Solar proton event * Solar radiation * Solar radius * Solar variation * Solar wind * Sunspots * Timeline of solar astronomy | width=210 align=left | ===See related=== * Airglow * Astronomical twilight * Birkat HaHammah * Eclipse * Heliostat * Polar aurora * Solar power * Solar deity * UV index |} ==External links== * [http://sohowww.nascom.nasa.gov/data/realtime-images.html Current SOHO snapshots] * [http://soi.stanford.edu/data/farside/index.html Far-Side Helioseismic Holography] from [http://www.stanford.edu Stanford] * [http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html NASA Eclipse homepage] * [http://sohowww.nascom.nasa.gov/ Nasa SOHO (Solar & Heliospheric Observatory) satellite][http://sohowww.nascom.nasa.gov/explore/faq/sun.html FAQ] * [http://soi.stanford.edu/results/sounds.html Solar Sounds] from [http://www.stanford.edu Stanford] * [http://www.spaceweather.com Spaceweather.com] * [http://scienceworld.wolfram.com/astronomy/Sun.html Eric Weisstein's World of Astronomy - Sun] * [http://www.astro.uu.nl/~strous/AA/en/antwoorden/zonpositie.html The Position of the Sun] * [http://www.lmsal.com/YPOP/FilmFestival/index.html A collection of solar movies] * [http://www.solarphysics.kva.se/ The Institute for Solar Physics- Movies of Sunspots and spicules] * [http://science.msfc.nasa.gov/ssl/pad/solar/default.htm NASA/Marshall Solar Physics website] Sun Yellow dwarfs ang:Sunne fa:خورشید la:Sol li:Zon ms:Matahari nah:Tonatiuh nds:S?nn scn:Suli simple:Sun su:Panonpo? th:ดวงอาทิตย์ vi:Mặt Trời

Sun

I would understand if you had a list that said, "Bodies in the solar system:" but instead the title is "see also:" Why does it say: ===See also:=== * Sun If we do this, then we might as well put this on every article: ===See also:=== * This article I think putting a different title than "see also:" is the better way to go. :True, that; the standard approach for the others seems to be putting this under the external links section: ---- Solar system:
Sun - Mercury (planet) - Venus (planet) - Earth - Mars (planet) - Asteroids - Jupiter (planet) - Saturn (planet) - Uranus (planet) - Neptune (planet) - Pluto (planet) - Comets :with the divider included, so I'll try it that way. -- User:JohnOwens 22:06 Apr 4, 2003 (UTC) ::Hmm, it would work better without the section at the bottom about other uses of Sun, but it might do. -- User:JohnOwens :::I agree, the other uses of Sun are annoying. In fact I find all "other uses of article" to be annoying in articles I read. oh well. ---- oh $hit, sorry, I didn't realize that all solar system objects had the same thing at the bottom including the "self-link". sorry about that, revert if you like, then go from there. A self-link actually wouldn't be bad. It was the ugly bolded Sun part that looked kind of annoying. :No, they don't include a self-link, I cut & pasted from Mercury for that so I figured it'd look silly if Mercury was bolded in the example. But I didn't change ''Sun'' like it would be in keeping with the others, that's why it wasn't bold in the example above. -- User:JohnOwens ---- I just saw what you did, it looks better than what was there before. I think because the See also: was on the same link as the Sun before, so it looked a bit messy. But now there is a space, as well as the divider. cool. ---- Poor Yoric, I don't think it's a good idea to load up the table with all those random factoids. Wikipedia:WikiProject Astronomical Objects has a template for data about stars, and the more stuff the Sun's table gets cluttered up with the more it diverges from that. I'd suggest trying to work them into the body of the article's text instead. User:Bryan Derksen What does "Atoms undergoing chemical reaction to generate Luminosity" actually ''mean'', anyway? There are no chemical reactions in the Sun, it is composed of plasma. User:Bryan Derksen ---- Quote from the article: "This releases energy which escapes from the surface of the Sun as light." This statement is very misleading as it seems to suggest that energy ONLY escapes from the Sun as light, whereas energy is actually emitted from the Sun across most of the electromagnetic spectrum. :It is also to a much smaller extent released as the kinetic and thermal energy of solar wind plasma. I'll try rewriting the line. User:Bryan Derksen 03:16, 28 Mar 2004 (UTC) ---- Is there a reason that the Sun's vital statistics give its diameter but those of the planets give their radius? User:Marnanel 06:53, Apr 2, 2004 (UTC) ------- Can we put something on the sun's place within the galaxy and upwards in it? i.e. the sun itself rotates around the centre of a galaxy known as the milky way with a centre...user talk:BozMo--User:BozMo 20:27, 10 May 2004 (UTC) : I have copied over a little bit of info from Solar system to address this, but I'd like to see more information about how the Sun formed. User:Eric Forste 01:01, 1 Aug 2004 (UTC) : That sounds like a song, and I do believe there is a similar song. Let's see... [http://www.astrocappella.com/sun.shtml Sun Song] is not it. It's not in [http://www.ircc.cc.fl.us/atircc/commout/planetarium/astsongbook.pdf The Astronomer's Song Book]. Maybe I'm thinking of [http://www.astro.washington.edu/kevin/galaxy.html Monty Python's The Galaxy] User:SEWilco 03:56, 20 May 2004 (UTC) ------- Quote from the article: "3.9 � 10^45 atoms undergo nuclear reactions there every second" If this were true, the energy output per nuclear reaction would be somewhat less than 1 eV. If we calculate the number of fused hydrogen atoms from the solar power ouput we get about 3.8 � 10^38. Sure, it's less per atom involved in a single reaction (hydrogen first fuses so deuterium and then some more reactions occur), but the energy output of a single reaction is certainly much higher than 1 eV. I'll rewrite that sentence. User:193.171.121.30 14:51, 5 Jun 2004 (UTC) :The ''Chart of the Nuclides'' allows one to compute the mass defect as 4*1.00782504-4.0026033=0.0286969 amu (~0.72%), which translates into 4.28277 pJ or 26.7310 MeV. If the solar luminosity is 382.7 YW, then this means we have 8.936E+37 helions per second being produced. The number of individual reactions is triple that for the p-p chain, quadruple for the CNO chain. :User:Urhixidur 23:38, 2004 Sep 6 (UTC) == time left for the sun == can someone add info about estimates on how much longer the sun will exist before it dies? thanks! User:Kingturtle 03:49, 17 Sep 2004 (UTC) ::Ahem!!! I was just wondering this. You want a thing done right you gotta do it yrself, holmes =) User:Yeago 22:44, 11 Oct 2004 (UTC) Shouldn't the main photographical illustration be a visible-light image of the Sun, rather than an X-ray one? A nice one showing some sunspots and chromosphere will be much better than an X-ray image that looks nothing like one might see in a telescope. == H-Bombs and Sustainable Energy? == Just how relevant is "Physicists are able to replicate thermonuclear reactions with hydrogen bombs. Sustained nuclear fusion on Earth for electricity generation may be possible in the future, with nuclear fusion reactors."? I hesitate to delete it, because having more information is usually better than having less, but I thought I'd point out how strikingly awkward that inclusion is. == solar rotation == With regard to the Sun page, I was using Allen's Astrophysical quantities for the solar rotation, and the recommended value was 25.38 days. Looking at the rotation periods determined by a whole list of methods, that value had a standard deviation of about 0.6 days. (See solar rotation) Do we want to carry it out to seven decimal places? Also I saw the edit " This makes it possible for the Sun to rotate faster at its equator (about 24 days) than it does at higher latitudes (28 days near its poles)." Don't you mean about 25 days? I just want to make sure I know what you did there before I go and re-edit. User:PAR 04:27, 4 Jan 2005 (UTC) :The 24 day figure came from http://scienceworld.wolfram.com/astronomy/Sun.html; go ahead and double-check as this could be a typo. The IAU/IAG paper specifies the rotations for the gas giants as being magnetospheric, but doesn't say so for the Sun; it could very well be this is just an "average" equatorial surface feature period. I had been using too many digits (the IAU/IAG paper gave nine significant digits to all rotation rates, but buried in the text is a mention that added zeroes are not actually significant), so I trimmed it back to the IAU value of 14.1844 degrees per day, which works out to 25.3800 days (these two zeroes are significant, this time). :User:Urhixidur 04:46, 2005 Jan 4 (UTC) I'm still suspicious of so many digits, given that all those different methods give such varying results, but so be it. I'm sure, however, that the scienceworld quote is wrong. The relationship between solar synodic and sidereal periods is :

D'=\frac{YD}{Y-D}

where D' is synodic period, D is sidereal period, and Y is orbital period of the earth (1 year). Using D=25.38 days, Y=365.25 days, I get D'=27.275267... days. Scienceworld and Allen quote 27.2753, and the old quote from the sun page was equivalent to 27.275 days, so everything fits. I will change the 24 to 25. User:PAR 11:49, 4 Jan 2005 (UTC) :Thanks for clearing that up. You are rightly suspicious of the extra two digits in the IAU rotation period; I'm pretty sure this only an agreed-upon rotation value used to define the heliographic coordinate system. The Sun's true equatorial rotation period is probably somewhat different and probably varies over time (it certainly varies from point to point, if only because of the motion of the plasma). :User:Urhixidur 17:36, 2005 Jan 4 (UTC) == Solar fusion == We've been trying to work out solar fusion numbers over at Nuclear fusion and Talk:Nuclear fusion - see the "Check these numbers?" section. I'm hoping that some of you folks know more about the solar fusion process than what we were able to piece together and can double-check what we (I) came up with. Thanks. User:SMesser 21:26, 21 Jan 2005 (UTC) == Better picture? == All we have here are two SOHO pictures using the same special color filter. Can we not use a "normal light" picture on the top, possibly with a couple of sun spots? User:Awolf002 15:51, 22 Jan 2005 (UTC) :The problem is, our main source of PD solar system images is NASA/JPL, and they don't seem to have any boring yellow-light images of the Sun. -- User:Curps 20:03, 22 Jan 2005 (UTC) :OK, I found one. -- User:Curps 20:27, 22 Jan 2005 (UTC) Great! I was combing through NASA images, too. You were more sucessful than me. Thanks! User:Awolf002 03:16, 23 Jan 2005 (UTC) == Symbol == I'd like to see the symbol for the Sun in the article. --User:flockofpidgeons 24:06, 11 Feb 2005 (UTC) == German article of the Sun == The german of the Sun is superb. I dont know if any of you guys knows German well enough to reuse some of the material but some of the stuff they talk in detail there is not ever mentioned in this article. Regards! --User:Smartech 20:44, 13 Mar 2005 (UTC) I put it into Babelfish, played around with it a little, then put it on a page Sonne translation. Its not a good translation, but its readable. We can edit it, etc. and get an idea of what it is saying. User:PAR 00:54, 14 Mar 2005 (UTC) :I've moved this to a subpage of this talk page, Talk:Sun/German translation - it wasn't appropriate for it to be in the main namespace. --User:TempLogInforPageMove 16:28, 13 Apr 2005 (UTC) ::Just skimming over the babelfish translation, the main topics that the German article has that we don't are these, hopefully this list will provide some doable goals to work towards. :#More about the magnetic field :#Physical occilations :#History of the study of the sun :#visible features? :#history of culture related to the sun :#the development of the sun :#lots of references ::User:Rmrfstar 04:02, 13 Jun 2005 (UTC) == Matter - Energy Conversion == 4.26 million tonnes per second??? Drop the million and you have the correct figure. This can be checked by the famous E = Mc^2 :Indeed it can be checked, and if you do that carefully you'll find it really is 4.26 million tonnes per second, giving the solar luminosity of 3.8×10²⁶W. User:Worldtraveller 02:56, 6 May 2005 (UTC) == The Sun and eye damage == I removed the recently-contributed RED BOX!!!!! on eye damage and added a brief section on it, since this is such a persistent meme. Solar eye damage is a much-overblown hazard: it rarely (if ever) happens to the unaided eye, and there are reports of people staring at the Sun for literally hours with no lasting ill effects. Of course, it ''is'' possible to go blind by looking at the Sun through binoculars, but it's also possible to go blind by ramming a fork into the eyes, and there's no BIG RED BOX!!!!! on that page. Sorry for the sarcasm -- I just deal with this sort of thing a lot in Real Life, being a solar physicist. User:Zowie 21:48, 6 May 2005 (UTC) :Thanks for pointing out the oversight! I'll go add a BIG RED BOX!!! to the fork article right now, no need to trouble yourself. :) User:Bryan Derksen 02:10, 7 May 2005 (UTC) :: Due to the complication of driving a ton of metal, I took care of "Fork in the road". (User:SEWilco 02:54, 7 May 2005 (UTC)) :::Can anyone add information on the effects of viewing the sun at sunset or sunrise? I remember once watching an annular eclipse at sunrise and wondering if I should be staring at it or not. I guess I ended up doing that despite the various "IF YOU LOOK AT THE SUN AT ALL YOU WILL GO BLIND AND ALSO PERHAPS DIE" warnings. == See Also == There is a big list at the bottom of the article, "See Also". Isn't this what categories are for? Should there be a Sun category? User:Ebeisher 16:37, 26 May 2005 (UTC)

Sun

This category contains articles about the Sun, the star of the solar system. Solar system Type-G stars Yellow dwarfs th:Category:ดวงอาทิตย์

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