Astronomy Lab - The Stellar Spectra

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  1. Define a star.
    A star is a celestial body of gases that radiates energy derived from fusion reactions in its interior.
  2. Where do fusion reactions occur in a star?
    At the core.
  3. What type of energy do the fusion reactions that occur in a star create and where does what this energy travel to?
    Photons that are transferred to the surface of the star.
  4. Describe the path of a photon.
    Begins in the core, then to the radiative zone, then to the convection zone, where gas is heated by the outbound photons and the hot gas is carried to the visible surface of the star.
  5. What is the surface of the star called?
    The photosphere
  6. What are the determining factors in the temperature of the surface of a star?
    The star's mass and age.
  7. How much variation has been recorded in the differences in surface temperature of stars?
    Thousands of degrees.
  8. What is the surface temperature of the sun?
    6000 degrees C
  9. What is the surface temperature of the star Rigel?
    30,000 degrees C
  10. Other than temperature, what are some other characteristics of a star that have been recorded to have extreme variations.
  11. Define luminosity.
    The amount of energy emitted per unit of time.
  12. What are the determining factors in the luminosity of a star?
    The star's mass and age.
  13. Is there a correlation between luminosity and the surface of the star?
  14. What is the relation of a star's mass and it's luminosity and surface temperature?
    The greater the mass, the hotter and more luminous it is.
  15. What is the Hertzsprung-Russell (HR) Diagram, what is it built primarily from and when was it first described?
    A diagram showing the correlation between a star's mass and it's luminosity and surface temperature, built primarily from spectroscopic observations and it was first described between 1912 and 1914.
  16. Light is _______________________________.
    Nature's way of transporting energy through space
  17. Waves carry ___, so light is talked about as a wave.
  18. The characteristics of lightwaves.
    Wavelength, Frequency and Speed.
  19. Describe frequency.
    How many lightwaves pass your eye per second.
  20. What is the speed of light?
    300,000 km/sec.
  21. What is the range in waves of visible light?
    From about 350 nanometers (nm) to about 600 nm.
  22. What visible light wave is 350 nm?
  23. What visible light wave is 600 nm?
  24. How can you see the continuous spectrum of light?
    Putting a prism between you and a white light source.
  25. What will happen if you hold a prism up to a red neon sign rather than white light?
    You will only see a series of orange or red bands, not the entire rainbow of light from violet to red.
  26. What will happen if you hold a prism between your eye and a sodium streetlight?
    You will see only a few yellow bands.
  27. What does each different element have?
    Its own fingerprint of colors.
  28. What are the primary colors in the element Neon's spectrum?
    Red, orange and yellow.
  29. What are the primary colors in the element Mercury's spectrum?
    Green and blue.
  30. What are the primary colors in the element Hydrogen's spectrum?
    Red, green and blue, and the colors are more luminous than in air's spectrum.
  31. What are the primary colors in air's spectrum?
    Red, green and blue, but the colors aren't as luminous as in hydrogen's spectrum.
  32. How can you see the spectra of the stars?
    By putting a prism in front of a telescope.
  33. What kind of elements do the spectra of hot stars show?
    Light elements, such as hydrogen.
  34. What kind of elements do the spectra of cool stars show?
    Heavy elements.
  35. What is the spectrum of a star the result of?
    Absorption in the outer visible surface of the star.
  36. What does the outer visible surface of a star consist of, and what is the resulting spectrum observed as?
    Gases which absorb the continuum of light being emitted from the interior of the star, observed as an absorption spectrum.
  37. What does the observed absorption spectrum depend on?
    The composition of the gases and the surface temperature of the star.
  38. How many classes of spectra of stars, what are they, and how can you remember them?
    7, O B A F G K M, oh be a fine girl, kiss me.
  39. How are the classes of spectra of stars ordered?
    From hottest to coolest, and from most massive to least massive.
  40. What are the O type subdivisions?
    O5, O6, O7, O8 and O9.
  41. What are the B, A, F, G, M type subdivisions?
    For each type, the subdivisions start at 0 and continue to 9.
  42. What are the K type subdivisions?
    K0, K1, K2, K3, K4, K5, K6 and K7.
  43. What astronomical objects can a particular subdivision be? What does this indicate? How are the subdivisions labeled to show the various indications?
    A supergiant, a giant or a dwarf star. Luminosity and the size of the star. With the Roman Numerals I, III, and V.
  44. What kind of star is the Sun? What does this mean?
    G2V, meaning it is a cooler dwarf star, at 6000 C.
  45. Who began a program to obtain a spectra of stars and when did he/she do this?
    Harvard College Observatory Director Edward Pickering in 1886.
  46. When did Annie Jump Cannon join the team of the Harvard College Observatory?
  47. What happens when you burn different elements? Why is this important?
    They all produce different line patterns, so you can identify the different elements in a star by looking at the spectrum of it.
  48. How many types of spectra are there and what are they? Briefly describe each type and give an example.
    3, continuous (a full spectrum, from blue to red, rainbow), emission (produced by hot and glowing gas under high pressure, a neon sign) and absorption (hot gas under low pressure, no color, "dark lines", what happens in a star).
  49. Who essentially discovered absorption lines, and what are these dark lines called?
    Joseph Franhoefer, called Franhoefer lines.
  50. What pulls the color from absorption lines?
    The intervening cooler layers of gas.
  51. What is most tragic about Joseph Franhoefer?
    He died young, and it is widely believed if he hadn't he would have made many more significant scientific discoveries.
  52. Who standardized the classification of stars?
    Annie Jump Cannon, a deaf woman who worked at the Harvard College Observatory.
  53. What does Amy Jump Cannon have to do with Charlotte's Amateur Astronomer's Club.
    Cannon's granddaughter introduced her friend from college, Charlotte Kelly, to Cannon who was able to get her very interested in astronomy and eventually Kelly moved back to Charlotte and formed the AAC.
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Astronomy Lab - The Stellar Spectra
2014-04-22 01:14:19

Astronomy flash cards to learn about the stellar spectra.
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