Stellar Astronomy [Topic Test 2]

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Stellar Astronomy [Topic Test 2]
2014-10-09 18:57:18
astronomy NMC

Flashcards for my Stellar Astronomy class ~ Topic Test 2 Northwestern Michigan College
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  1. [1] Describe the Electromagnetic Spectrum.
    The electromagnetic spectrum describes all the wavelengths of light.

  2. [1] What distinguishes one type of electromagnetic radiation from another?
    The characteristic that distinguishes one from another is its wavelength (or frequency).
  3. [2] Describe and explain how emission and absorption lines are formed.
    Every element has a unique set of colors that act like a fingerprint.

    - Emission lines: When light given off by hot gas is decomposed using a prism, it is shown to be made up of colored lines.

    - Absorption lines: When white light shines trough a cold gas the resulting light , when decomposed is shown to have dark lines.

    The emission and absorption lines for the same element match.
  4. [2] In what sorts of cosmic objects would you expect to see either emission or absorption lines?
    Everything. The Sun, the planets, other stars, people, and so on. Everything is made up of elements.
  5. [3] Light travels at a finite speed in a vacuum. Why is this important to astronomers?
    Because they can use it as a measuring tool.
  6. [3] How far away is Mars in light time?
  7. [3] How far away is the Sun in light time?
  8. [3] How far away is the Andromeda Galaxy in kilometers?
  9. [4] Describe the problems with telescopes and why we cannot see objects in greater detail than we do today?
    • We just can't make them big enough at this point in time. They take up a lot of space and they are too heavy.
    • We also have to deal with light pollution and atmospheric interference.
  10. [5] Most large telescopes are not used for observing with the naked eye. Explain why they are not and what is used instead of the human eye to investigate celestial objects?
    The human eye is attached to an "imperfect recording device" also known as the human brain. We use CCD cameras, spectrographs and photometers instead.
  11. [6] Describe the different types of telescopes and what part of the Electromagnetic Spectrum they are used for analyzing.
    • Refracting telescopes: bend light, need to be long, have large heavy lenses / analyzing visible light
    • Reflecting telescopes: curved mirror, much greater diameter, most modern telescopes / analyzing visible light
    • Gamma-ray telescopes: best above the atmosphere / analyze gamma rays
    • X-ray telescopes: analyze x-rays
    • Infrared & Ultraviolet telescopes: best above the atmosphere / each analyze IR and UV rays
    • Radio telescopes: large, generally immobile, limited / analyze radio waves
  12. [7] The Sun's internal structure: the core, the radiative zone, and the convection zone.
    Describe each of the three components and give specific details.
    Core: hottest, where fusion occurs

    Radiative: transfers energy from the core out

    Convective: hot gases rise, cool gases fall
  13. [8] The Sun's "atmosphere": the photosphere, the chromosphere, and the corona.
    Describe what can be observed from each layer and what each is revealing about the Sun.
    Photosphere: texture, surface, sunspots

    Chromosphere: flares, promeneces, like the first layer of Earth's atmosphere

    Corona: hot, high energy, low density, like the Earth's magnetic field

    They reveal the emission of energy, the level of energy and where the Sun is in its cycle.
  14. [9] Describe the activity of the Sun over its 11-year cycle.
    From peak to peak the number of sunspots visible on the Sun's surface increase.
  15. [9] How is the Sun's 11-year cycle important to the Earth?
    It could knock out electric grids on Earth as well as mess with our satellites which affects things like cell phones, GPS, and airplanes.
  16. [9] If a Coronal Mass Ejection (CME) travels at approx. 1500km/s, how long will it take the energy to reach the Earth?
    • t=d/v
    • t= (150,000,000 km)/(1,500 kmps)
    • t= 100,000 s

    approx. 27.78 hrs, so it would reach Earth about 2 days later
  17. [10] How many Earths can fit inside the Sun?
       = 1,295,029

    So approx. 1.3 million Earths can fit inside the Sun.
  18. [10] How many basketballs can fit inside the Sun?