What Causes Graininess On The Sun

By | 23/11/2022

Consider the Earth, the Moon, and all the other planets in our solar arrangement. Think well-nigh the mass that all those objects must accept when they are all added together. Added all together, however, they business relationship for only 0.2% of the total mass of the solar system. The Lord’s day makes up the remaining 99.viii% of all the mass in the solar system (Figure 24.17)! The Sun is the center of the solar organisation and the largest object in the solar system. Our Sun is a star that provides calorie-free and oestrus and supports near all life on Earth.

In this lesson you will learn about the features of the Dominicus. We will hash out the composition of the Sun, its atmosphere, and some of its surface features.

Figure 24.17: The Sun.

Layers of the Dominicus

The Sunday is a sphere, but unlike the Earth and the Moon, is not solid. Virtually atoms in the Sun exist asplasma, or a quaternary land of matter made up of superheated gas with an electrical charge. Our Sun consists nearly entirely of the elements hydrogen and helium. Because the Lord’s day is not solid, information technology does non take a defined outer purlieus. It does, however, have a definite internal structure. At that place are several identifiable layers of the Sun:

Thecadre is the innermost or central layer of the Dominicus. The core is plasma, merely moves similarly to a gas. Its temperature is around 27 meg degrees Celsius. In the core, nuclear reactions combine hydrogen atoms to form helium, releasing vast amounts of energy in the process. The free energy released so begins to movement outward, towards the outer layers of the Dominicus.

Theradiative zone is just outside the core, which has a temperature of almost 7 million degrees Celsius. The energy released in the core travels extremely slowly through the radiative zone. Particles of calorie-free called photons can only travel a few millimeters before they hit another particle in the Lord’s day, are absorbed then released over again. It can take a photon every bit long every bit 50 1000000 years to travel all the way through the radiative zone.

Theconvection zone surrounds the radiative zone. In the convection zone, hot material from near the Sun’southward center rises, cools at the surface, and then plunges dorsum down to receive more oestrus from the radiative zone. This motility helps to create solar flares and sunspots, which we’ll learn more near in a bit. These first three layers make upwardly what nosotros would actually call “the Sun”. The adjacent iii layers brand up the Dominicus’s atmosphere. Of grade, there are no solid layers to any part of the Dominicus, so these boundaries are fuzzy and indistinct.

The Dominicus’s “Temper”

Thephotosphere is the visible surface of the Sun (Figure 24.18). This is the region of the Sun that emits sunlight. It’s also one of the coolest layers of the Sunday—merely near 6700°C. Looking at a photo of the Lord’s day’due south surface, y’all can see that it has several different colors; oranges, yellowish and reds, giving it a grainy appearance. We cannot encounter this when we glance quickly at the Sun. Our eyes tin’t focus that quickly and the Sun is too bright for us to look at for more a brief moment. Looking at the Sun for any length of fourth dimension can cause blindness, so don’t endeavour it! Sunlight is emitted from the Sun’s photosphere. A fraction of the lite that travels from the Sunday reaches Globe. Information technology travels as light in a range of wavelengths, including visible low-cal, ultraviolet, and infraredradiation. Visible calorie-free is all the low-cal nosotros can see with our eyes. We tin’t see ultraviolet and infrared radiations, but their furnishings can nonetheless be detected. For example, a sunburn is caused by ultraviolet radiation when yous spend likewise much time in the Lord’s day.

Figure 24.18: The layers of the Sun.

Thechromosphere is the zone about 2,000 kilometers thick that lies directly above the photosphere. The chromosphere is a thin region of the Sun’southward atmosphere that glows red as it is heated by energy from the photosphere. Temperatures in the chromosphere range from about 4000°C to about 10,000°C. Jets of gas fire up through the chromosphere at speeds up to 72,000 kilometers per hour, reaching heights as high equally 10,000 kilometers.

Thecorona is the outermost layer of the Dominicus and is the outermost role of its atmosphere. Information technology is the Sunday’s halo or “crown”. Information technology has a temperature of 2 to v one thousand thousand degrees Celsius and is much hotter than the visible surface of the Sun, or photosphere. The corona extends millions of kilometers into space. If you e’er have the risk to meet a full solar eclipse, y’all volition be able to meet the Sunday’southward corona, shining out into infinite.

In the Sunday’south core,nuclear fusion reactions generate energy by converting hydrogen to helium. Fusion is a process where the nuclei of atoms bring together together to form a heavier chemical element. Fusion reactions in the Sun’s core produce free energy, which we experience as heat and light. The rest of the Lord’s day is heated by movement of rut energy outward from the core. Calorie-free energy from the Sun is emitted from the photosphere. Information technology travels through space, and some of it reaches the Earth. The Lord’s day is the source of almost all the free energy on Earth and sunlight powersphotosynthesis, as well every bit warming and illuminating our Earth.

Surface Features of the Sun

The most noticeable surface feature of the Dominicus is the presence of sunspots, which are cooler, darker areas on the Sun’s surface. Sunspots are only visible with special low-cal-filtering lenses. They exhibit intense magnetic activity. These areas are cooler and darker because loops of the Sun’s magnetic field suspension through the surface and disrupt the polish transfer of heat from lower layers. Sunspots usually occur in pairs. When a loop of the Sun’s magnetic field breaks through the surface, it usually creates a sunspot both where it comes out and i where it goes back in once more. Sunspots usually occur in xi year cycles, beginning when the number of sunspots is at a minimum, increasing to a maximum number of sunspots and then gradually decreasing to a minimum number of sunspots once again.

If a loop of the sun’due south magnetic field snaps and breaks, information technology creates solar flares, which are violent explosions that release huge amounts of free energy (Figure 24.19). They release streams of highly energetic particles that make up the solar air current. The solar current of air tin can be dangerous to spacecraft and astronauts. It sends out large amounts of radiation, which can harm the human being body. Solar flares have knocked out entire power grids and tin disturb radio, satellite, and cell phone communications.

Figure 24.19: A solar flare.

Some other highly visible feature on the Sun are solar prominences. If plasma flows forth a loop of the Sun’due south magnetic field from sunspot to sunspot, it forms a glowing arch that reaches thousands of kilometers into the Sun’s atmosphere. Prominences can last for a day to several months. Prominences are also visible during a total solar eclipse.

A beautiful and mysterious effect of the Sun’s electrically charged particles are auroras, which course effectually the polar regions high in Globe’s temper. Gases in World’southward atmosphere are excited by the electrically charged particles of the solar air current and glow producing curtains of low-cal, which bend and alter as you watch.

Lesson Summary

  • The mass of the Sun is tremendous. It makes up 99.8% of the mass of our solar arrangement.
  • The Lord’s day is mostly fabricated of hydrogen with smaller amounts of helium in the form of plasma.
  • The chief part of the Sun has three layers: the core, the radiative zone, and the convection zone.
  • The Dominicus’southward atmosphere as well has three layers: the photosphere, the chromosphere, and the corona.
  • Nuclear fusion of hydrogen in the core of the Dominicus produces tremendous amounts of energy that radiate out from the Lord’s day.
  • Some features of the Sun’s surface include sunspots, solar flares, and prominences.

Review Questions

  1. In what fashion does the Sun support all life on Globe?
  2. Which 2 elements brand up the Sun almost in entirety?
  3. Which process is the source of heat in the Sun and where does information technology accept place?
  4. Some scientists would like to programme a trip to take humans to Mars. I of the things continuing in the way of our ability to do this is solar wind. Why volition nosotros have to be concerned with solar wind?
  5. Describe how movements in the convection zone contribute to solar flares.
  6. Do you think fusion reactions in the Lord’s day’s core will keep forever and go along with no stop? Explicate your answer.


Thin layer of the Sun’s atmosphere that lies directly above the photosphere; glows red.
convection zone
Layer of the Sun that surrounds the Radiative Zone; energy moves as flowing cells of gas.
Innermost or fundamental layer of the Sun.
Outermost layer of the Dominicus; a plasma that extends millions of kilometers into space.
nuclear fusion
The merging together of the nuclei of atoms to form new, heavier chemical elements; huge amounts of nuclear energy are released in the process.
Layer of the Sunday that we see; the visible surface of the Sun.
The process that green plants apply to convert sunlight to energy.
A high energy, high temperature class of matter. Electrons are removed from atoms, leaving each atom with an electrical charge.
Electromagnetic energy; photons.
radiative zone
Layer of the Sun immediately surrounding the cadre; energy moves atom to atom as electromagnetic waves.
solar flare
A fierce explosion on the Dominicus’southward surface.
solar wind
A stream of radiations emitted by a solar flare. The solar wind extends millions of kilometers out into space and can even attain the Earth.
Libation, darker areas on the Sun’s surface that take lower temperatures than surrounding areas; sunspots usually occur in pairs.

Points to Consider

  • If something were to all of a sudden cause nuclear fusion to stop in the Lord’s day, how would we know?
  • Are there whatever types of dangerous energy from the Sun? What might be affected by them?
  • If the Sun is all made of gases like hydrogen and helium, how can information technology have layers?

Source: https://courses.lumenlearning.com/suny-earthscience/chapter/the-sun/