1 / 59

Exploring the Universe

Exploring the Universe. Chapter 26. 26.1 Energy From the Sun. Review of Vocabulary. Core - central region, where nuclear fusion occurs. How does the sun produce energy?. Energy is produced in its central region by the fusion of hydrogen nuclei into helium nuclei.

mcribb
Download Presentation

Exploring the Universe

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Exploring the Universe Chapter 26

  2. 26.1 Energy From the Sun

  3. Review of Vocabulary • Core - central region, where nuclear fusion occurs.

  4. How does the sun produce energy? Energy is produced in its central region by the fusion of hydrogen nuclei into helium nuclei.

  5. Question: What new isotope is produced by this fusion reaction? • hydrogen-1 • helium-4 • oxygen-16 • none

  6. What new isotope is produced by this fusion reaction? • hydrogen-1 • helium-4 • oxygen-16 • none

  7. 26.1 Forces in Balance May the force be with you!

  8. Why does the sun remain stable over time? • Inward pull of gravity balances the outward push of thermal pressure from nuclear fusion.

  9. Question: What would happen to the sun if it began to run out of fuel? • It would become cooler very quickly. • The force of gravity would decrease. • Its core would expand as thermal pressure increased. • Its core would shrink as thermal pressure decreased.

  10. What would happen to the sun if it began to run out of fuel? • It would become cooler very quickly. • The force of gravity would decrease. • Its core would expand as thermal pressure increased. • Its core would shrink as thermal pressure decreased.

  11. 26.1 The Sun’s Interior

  12. Interior facts • The sun’s interior consists of 3 parts. • Core • Radiation zone • Convection zone • Energy moves through the sun in two main ways: • Radiation • Convection

  13. Review of Vocabulary • Radiation zone - region of highly compressed gas where energy is transferred by the radiation.

  14. Review of Vocabulary • Convection zone - the outer layer of the sun's interior, where energy is transferred mainly by convection currents.

  15. Remember how convection currents move…..

  16. 26.1 The Sun’s Atmosphere Very unlike Earths!

  17. Exterior facts • The sun's atmosphere consists of three layers. • Photosphere • Chromosphere • Corona These regions are outside the convection zone.

  18. Photosphere  • Innermost layer • Visible surface of the sun • 500 kilometers thick • Temp: approximately 5800 K

  19. Chromosphere • Middle layer • Temp: increases to nearly 10,000 K • At high temperatures, hydrogen gas emits a reddish light. • This light gives it its name, which means “sphere of color.” • Can see this during a total solar eclipse.

  20. Corona • Outermost layer • Gases in the corona are thin • Temp: Gases super hot (about 1 million K) • Thermal energy in it is relatively small. • Usually seen only during solar eclipses.

  21. 26.1 Features of the Sun’s Atmosphere

  22. Sun has got a magnetic personality! • The sun's magnetic field produces striking features on and above its surface • Such as: • Sunspots • Prominences • Solar flares.

  23. Sunspots • Areas of gas in the photosphere that are cooler than the surrounding gases. • Spots can be larger than Earth • Associated with intense magnetic fields on the sun. • Last from a few hours to a few months. • Numbers varies in cycles, with about 11 years separating one sunspot peak from the next.

  24. Prominences • Huge loops of gas that erupt from sunspot regions. • Extend from the photo S into the chromo S and sometimes into the corona. • Travel along the magnetic field lines that connect sunspots. • Heights can be more than 100,000 kilometers above the sun's surface.

  25. Solar Flares • Sudden release of energy • Surface erupts dramatically, producing X-rays and hurling charged particles into space. • Heat the corona to a temps near 20 million K and produce solar wind. • High-energy particles and radiation can reach Earth • Cause magnetic storms in Earth's upper atmosphere. • Storms disrupt electric power transmission, radio, TV, and phone signals.

  26. Question: How can sunspots be recognized on the sun's surface? • Sunspots appear darker than the surrounding photosphere. • Sunspots appear lighter than the surrounding photosphere. • It is hard to distinguish sunspots from the surrounding photosphere. • Sunspots always appear in definite groups.

  27. How can sunspots be recognized on the sun's surface? • Sunspots appear darker than the surrounding photosphere. • Sunspots appear lighter than the surrounding photosphere. • It is hard to distinguish sunspots from the surrounding photosphere. • Sunspots always appear in definite groups.

  28. 26-2 Stars

  29. Stars • Star-a large, glowing ball of gas in space, which generates energy through nuclear fusion in its core. • the sun is the closest star to Earth

  30. Distances • Astronomical Unit- (AU) distance from Earth to the Sun~ (150,000,000Km) • Most of Space is empty, so huge distances are required. • Light Year-distance light travels in 1 year. • Approx. 9.5 trillion Km (at 300,000 Km/s) • 1 light year=63 AU

  31. Parallax • Apparent change in position of an object with respect to a distant background. • How we measure the distance of stars • Greater parallax=closer star • Winter to Summer

  32. Properties of Stars • Color &Temperature • The color of a star indicates its surface temperature( think color spectrum) • Brightness • closer you are to a light the brighter it appears( not always) • Apparent brightness- brightness appears from Earth • Absolute brightness-how bright the star really is • Can be calculated using distance (if known)

  33. Star props. cont’ • Size &Mass • Diameter can be calculated using temp, and brightness • Mass can be calculated using gravitational interactions • Composition-what is it made of

  34. Giants and Dwarfs • Giants- large, bright stars that are smaller and fainter supergiants • White dwarfs- small dense remains of a low-medium-mass star.

  35. Hertzsprung -Russell Diagram

  36. 26-3 Life Cycle of Stars • Stars change over their lifespan just like animals change throughout their life. • Nebula-a large cloud of gas and dust spread out over a large volume of space. • They can have different appearances bright or dark

  37. Stars • Stars are created due to gravity. • Contacting clouds of gas/dust with enough mass to form a star are called protostars. • Stars are formed when contracting of gas/dust become so dense/hot that nuclear fusion occurs.

  38. Adult Stars • Most of a stars life is in the main sequence on the H-R Diagram. • Mass determines how long it stays in this sequence. • More mass=brighter stars, but they use up fuel quicker.

  39. Death of a Star • When a star runs out of fuel (Hydrogen), gravity overtakes the star. • The core cools • Temperatures rise, causing swelling on exterior. • The dwindling supply of fuel in a star’s core ultimately leads to the star’s death as a white dwarf, neutron star, or black hole.

  40. Dying Stars • Planetary nebula-glowing cloud of gas surrounding a dying star. (low mass) • Supernova-collapse of outer layer of dying high mass star, huge explosion producing more light than the entire galaxy generates

  41. Evolution of Stars

  42. Dying Stars • Neutron Star-remnants of high-mass star that has exploded supernova. • Spinning neutron stars that give off strong pulses of radio waves are called pulsars. • Black Hole-an object whose surface gravity is so great that even electromagnetic waves cannot escape it.

  43. 26-4 Groups of Stars

More Related