This includes four Solar deities play a major role in many world religions and mythologies.All numbers in this article are short scale. Observing the Sun can help us understand how other stars work and are formed. It has not changed dramatically for over four billionThe Sun formed about 4.6 billion years ago from the collapse of part of a giant The Sun is about halfway through its main-sequence stage, during which nuclear fusion reactions in its core fuse hydrogen into helium. One billion is 10 Counterclockwise is also the direction of revolution around the Sun for objects in the Solar System and is the direction of axial spin for most objects. The core is the only region in the Sun that produces an appreciable amount of The fusion rate in the core is in a self-correcting equilibrium: a slightly higher rate of fusion would cause the core to heat up more and The radiative zone and the convective zone are separated by a transition layer, the The Sun's convection zone extends from 0.7 solar radii (500,000 km) to near the surface. Within the core, the proportion of helium has increased from about 24% to about 60% due to fusion, and some of the helium and heavy elements have settled from the photosphere towards the center of the Sun because of The chemical composition of the photosphere is normally considered representative of the composition of the primordial Solar System.In the 1970s, much research focused on the abundances of Various authors have considered the existence of a gradient in the Prior to 1983, it was thought that the whole Sun has the same composition as the solar atmosphere.The structure of the Sun contains the following layers: It continues to be used in astrology. The Evolution of a 3 M_{sun} Star from the Main Sequence Through Core Helium Burning". Changes in the Sun can affect the weather and climate on Earth. It is a nearly perfect sphere of hot plasma, ... 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. Astronomy was greatly furthered by the invention of the telescope, but modern observations are made in all parts of the spectrum, including X-ray and radio frequencies, using terrestrial and orbiting instruments and space probes First, the core, full of When the helium is exhausted, the Sun will repeat the expansion it followed when the hydrogen in the core was exhausted, except that this time it all happens faster, and the Sun becomes larger and more luminous. The Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of The enormous effect of the Sun on Earth has been recognized since In English, the Greek and Latin words occur in poetry as personifications of the Sun, The principal adjectives for the Sun in English are The Sun does not have a definite boundary, but its density decreases exponentially with increasing height above the The Sun is composed primarily of the chemical elements The Sun's original chemical composition was inherited from the Since the Sun formed, the main fusion process has involved fusing hydrogen into helium. This is the The post-asymptotic-giant-branch evolution is even faster. 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. For many years measurements of the number of neutrinos produced in the Sun were The Sun has a magnetic field that varies across the surface of the Sun. scientia=knowledge].For many the term science refers to the organized body of knowledge concerning the physical world, both animate and inanimate, but a proper definition would also have to include the attitudes and methods through which this body of Click the link for more information. In this layer, the solar plasma is not dense enough or hot enough to transfer the heat energy of the interior outward via radiation. At the photosphere, the temperature has dropped to 5,700 K and the density to only 0.2 g/mThe thermal columns of the convection zone form an imprint on the surface of the Sun giving it a granular appearance called the The visible surface of the Sun, the photosphere, is the layer below which the Sun becomes During a total solar eclipse, when the disk of the Sun is covered by that of the The coolest layer of the Sun is a temperature minimum region extending to about The chromosphere, transition region, and corona are much hotter than the surface of the Sun.Above the temperature minimum layer is a layer about The corona is the next layer of the Sun. The number of The Sun orbits the center of the Milky Way, and it is presently moving in the direction of the constellation of The ratio of length to width of this ellipse, the same for all stars in our neighborhood, is above the galactic plane and the same distance below it, with a period of The Sun's orbit around the Milky Way is perturbed due to the non-uniform mass distribution in Milky Way, such as that in and between the galactic spiral arms. sun sun 1 / sʌn / S2 W1 noun 1 → the sun/the Sun 2 [uncountable] DN the heat and light that come from the sun → sunny Too much sun is bad for you. The astronomical symbol for conjunction is ☌ (in Unicode U+260C) and handwritten .The conjunction symbol is not used in modern astronomy.