1. Stars & The Electromagnetic Spectrum Notes
Test – Thursday, 1/30
Textbook & Online Resources:
Chapter 3 – Lesson 4: Characteristics of Stars
Chapter 3 – Lesson 6: The Sun
Chapter 6 – Lesson 4: Exploring Space with Images

2. Star
Huge sphere of glowing gas, made mostly of hydrogen, that produces energy through nuclear fusion

4. Stars are classified by the following physical properties…

5. Temperature & Color
Cool Stars – red – 3,200oC Our Sun – yellow – 5,500oC Hot Stars - blue – 20,000oC
Image from Hubble Telescope

7. Size
Small Stars – White dwarf stars (size of earth) and Neutron stars (20 km in diameter)
Medium Stars – Our Sun
Large Stars – Giant Stars or Supergiant Stars

8. Dwarf Star .
Neutron Star

9. Dwarf Star

13. ***Size of stars are measured by radius, which is the distance from the center to the outside edge of the circle. (plural = radii)

14. Brightness Apparent Magnitude (AKA – Apparent Brightness)
A star’s brightness as seen from Earth
Closer stars appear brighter than distant stars

15. Absolute Brightness
The brightness a star would have if it were a standard distance from Earth.
How bright the star REALLY is.
Calculated using the star’s apparent magnitude & distance from earth.

18. This shows how large the sun would appear to be if you were on different planets.

19. Brightness of a star depends on temperature & size.
Ex: Hot stars = more bright cool stars = less bright
Big stars = more bright small stars = less bright

20. Hertzsprung-Russell Diagram H-R Diagram

22. Proxima Centauri's the nearest star
Proxima Centauri's the nearest star. The celestial bodies that follow are: Alpha Centauri A, Toli, Barnard's Star, Wolf 359, Laland 21185, Sirius A, Sirius B, BL Ceti, UV Ceti, Ross 154, Ross 248, Epsilon Eridani, Lac 9352, Ross 128, EZ Aquarii A, EZ Aquarii B, EZ Aquarii C, Procyon A. Those are the stars that are nearest to me, Tra la la and fiddle dee dee!

23. http://www. youtube. com/watch

25. The Sun

26. Facts about the Sun 150 million km from Earth
It takes about 8 minutes for light from the sun to reach Earth.
About 1 million Earths could fit inside the sun.
Sun’s energy = 6 Trillion nuclear bombs each second

27. The star at the center of our solar system is the sun.
The sun is a medium-sized star
The sun is about 5 billion years old, and has about another 5 billion years left to burn

28. The Sun’s interior is made up of 3 layers

29. The Core Where the sun produces energy by nuclear fusion
Hydrogen atoms combine to form helium atoms, which releases energy.
The core is over 15,000,000o C

30. The Radiation Zone
Energy produced in the core moves outward through the radiation zone.
Moves very slowly because the gas is so dense.
***Takes 100,000 years for energy to move through.

31. The Convection Zone Outermost layer
Hot gases rise from the bottom, cool as they reach the surface, then sink again.
This moves energy to the sun’s surface.

32. The sun also has an atmosphere that extends into space.
The Sun’s atmosphere has 3 layers
1. Photosphere
2. Chromosphere
3. Corona

34. Sun Rotating Video

35. Sunspots
Areas of gas on the sun’s surface that are cooler than the gasses around them.
Cooler gasses are less bright, so they make dark spots.

36. Prominences
A huge loop of gas that protrudes from the sun’s surface, linking parts of sunspot regions

37. Solar Flares
An eruption of gas from the sun’s surface that occurs when the prominences suddenly connect.

39. Sun’s energy comes to Earth by radiation
Most of the energy from the Sun is Infrared radiation, visible light, or ultraviolet radiation.

40. The Electromagnetic Spectrum

41. A good way to remember this is…
Rabbits Meet In Very Unusual eXpensive Gardens

42. Radio Waves
Carry Radio, TV, Computer signals
Weakest, least dangerous

43. Microwaves
Microwave ovens, cell phones, radar

44. Infrared Waves
“Pure” heat, Heat lamps, remote controls, some photography
***Most of the Sun’s energy

45. Visible Light What you can see
White light – “Pure” light, contains all other colors, if separated by a prism
Colors - Roy G. Biv

46. Ultraviolet Some helps skin produce vitamin D
Too much causes eye damage, sunburn, & skin cancer

47. X-Ray
Used to view bones/teeth
Can cause cancer in high amounts

48. Gamma Ray Nuclear Radiation Can cause radiation poisoning,
cancer, death

49. The electromagnetic spectrum can help scientists view space by allowing them to see other types of energy that would be invisible with a regular telescope.

50. Regular Saturn – Saturn in UV Light

51. What our galaxy looks like…
With your eyes or telescope
infrared
radio
X-ray
gamma ray