The Sun Chapter 28
28.1 – Structure of the Sun Throughout most of history people thought the sun’s energy came from fire Not until the last 100 years did scientist discover the source There are three layers to the sun: the core, the inner zones, and the atmosphere
28.1 – The Core The core is at the center of the sun and makes up about 10 percent of the sun The temperature at the core is about 15,000,000 oC No liquid or solid can exist at that temperature
28.1 – The Core 75 % of the sun is made of Hydrogen and the rest is mostly helium Hydrogen fusion is the process by which the sun gets its energy Two hydrogen atoms collide and combine to form a helium atom When this happens energy is given off
28.1 – The Inner Zones The energy produced in the core moves through two inner zones before reaching the surface The first zone around the core is the radiative zone. The temperature here is about 2,500,000 oC
28.1 – The Inner Zones The second zone is the convection zone. It has a temperature about 1,000,000oC Hot gases carry energy to the surface and cooler gases fall to gather more energy Heat gets to the surface by gases rising and falling
28.1 – The Sun’s Atmosphere Surrounding the convection zone is the atmosphere. Although the sun is all gas the atmosphere is the upper most region of the sun The atmosphere has 3 layers
28.1 – The Sun’s Atmosphere The first layer is the photosphere The temperature here is about 6,000 oC Most energy given off here is from visible light
28.1 – The Sun’s Atmosphere The second layer of the atmosphere is the chromosphere, or color sphere Its temperature is between 4,000 and 50,000 oC
28.1 – The Sun’s Atmosphere The outer most layer is the corona or crown This layer is a huge cloud of gas heated to a temperature about 2,000,000 oC Some electrically charged particles escape from the corona, they are called the solar wind
28.1 – The Sun’s Atmosphere The chromosphere and corona are not usually seen from earth during the day If we have a solar eclipse we can see them around the outline of the moon