Astronomy 101

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Astronomy 101
2010-09-15 19:22:08

Astronomy 101 Test 1
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  1. Scientific Method?
    • -Facts/ Observations
    • -Organize ideas/ theory
    • -Predictions & testing
  2. Powers of 10?
    • 10^3 = 1000
    • 10^2 = 100
    • 10^1 = 10
    • 10^0 = 1
    • 10^-1= .1
    • 10^-2=.01
    • 10^-3=.001
  3. What is Celestial sphere? What is Ecliptic? Angle between celestial equation and ecliptic?
    • Imaginary sphere surrounding earth, which all objects in sky were considered attached to.
    • Apparent path of sun, relative to stars on celestial sphere,over course of yr.
    • Angle is 23.5 degrees.
  4. Responsible for seasons?
    1)Summer Solstice? 2)Winter Solstice?1)Verrnal equinox? 2)Autumal equinox?
    • change in avg temp & length of day due to tilt of earth's axis respect to plane of its orbit.
    • 1)Pt on ecliptic where sun is at northermost pt above celestial equator(near June21)
    • 2)Pt on ecliptic where sun is at sourthermost pt below celestial eq. (near Dec 21)
    • 1) Date when sun crosses celestial eq. moving northward (near march 21)
    • 2) Date when sun crosses celestial eq. moving southward (near sept 22)
  5. What is Precession?
    • Slow change in the direction of the rotation axis of a spinning object cause by external gravitational influence.
  6. Moon Phases? New Moon? Quarter Moon? Full Moon?
    • Appearance of sunlit face of moon at different pts along orbit(seen fr. earth).
    • Phase, none of lunar disk is visible.
    • Phase,moon appears half disk.
    • Phase,appears complete circular disk in sky.
  7. Eclipse? Lunar Eclipse? Partial Eclipse? Total Eclipse?
    • Event during which one body passes in front of another, so light blocked.
    • Celestial event which moon passes through shadow of earth(temporary darken surface)Celestial event only part of covered body is blocked from view.
    • Celestial event which one body is completely blocked from view by another.
  8. Measurement of distance. Trangulation?
    • One distance measurement method.
  9. Parallax?
    • apparent motion of relatively close object w/ respect to a more distance background as the location of the obserber changes.(shift of object from different line of site)
  10. Retrograde Motion?
    • Backward, westward loop traced out by a planet w/ respect to fixed stars.
  11. Geocentric Vs Heliocentric
    • Geocentric: model of solar system that holds earth is at enter of universe & all bodies orbit around it.(Aristotle)
    • Heliocentric:model of solar system that is centered on Sun, while earth in motion about sun.(Copernicus)
  12. Kepler's First Law
    • The orbital paths of planets are elliptical with sun at one focus.
    • Distance from focus to ellipse to other focus stay same.
  13. Kepler's Second Law
    • Imaginary line connecting the Sun to any planet sweeps out equal areas of ellipse in equal intervals of time.
    • Swing out equal areas in equal time when close/far to sun.
  14. Kepler's Third Law and AU?
    • The square of a planet's orbital period is proportional to the cube of its semi major axis.
    • P2(yr)= a3(AU)/ M(M0)

    Average distance btw earth and sun.
  15. Newtons Law One and Two
    • 1)An object at rest remain at rest, moving object continues straight line at constant speed, unless external force changes their state of motion. ( See Pic)
    • 2) The Acceleration(change of speed) of object is directly proportional to the net applied force and inversely proportional to the objects mass.
  16. Newtons Third Law and Gravity
    • To every action(force) there is an equal and opposite reaction.
    • Force= GM1*M2/r2 (product masses/ distance)
  17. Light and wavelength
    • Light described as wave.
    • Number of meters needed for wave to repeat itself at given moment in time.
  18. Electromagnetism
    Union of electricity and magnetism, which don't exist as independent qualities but in reality are two aspects of single physical phenomenon.
  19. Radio, inferred, visible ultraviolet, x-ray, gamma-ray and Frequency
    • Radio(AM FM) Inferred (far near) Visible(micron oms) Ultraviolet (near far) x-ray (soft hard)
    • Number of crest going by in hertz
  20. Wien's Law and Stefan's Law.
    Wavelength(max) = 0.29 cm/ T (temp)

    F= o T^4
  21. Continuous Spectra
    • spectra in which radiation is distributed over all freqs (EX: blackbody radiation emitted by hot, dense body)
  22. Emission Lines
    • bright line in specific location of spectrum of radiating material, corresponding to emission o flight at certain freq. (EX: heated gas in glass container)
  23. Absorption Lines
    • Dark line in an otherwise continuous bright spectrum, where light within one narrow freq range has been removed. (missing lines is emission lines)
  24. Formation of Spectral Lines
  25. Astronomical Spectroscopy
    • -Compostion ( what is there)
    • -Abundances ( how much is there)
    • -temp ( wiens law, black body,/other)
    • -pressure ( Broadens lines)
    • - Rotation ( doppler effect)
    • -magnetic field( zeeman effect)
    • -electric field( stark effect)
  26. -Doppler effect
    • (motion towards/ away from obserber)(pitch high toward, low going away)
  27. Reflecting Telescope
    • Visible light telescope, curved mirror to gather& focus light from distance object.
  28. Refracting telescope
    • Telescope that uses a lens to gather 7 focus light from distance object.( small ie binoculars) ( no modern research use this )
  29. Reflect Telescope
    • side eye view mirror
  30. Refract Telescope
    • see through lens
  31. Photographic plate? Resolution? Seeing disk? Vermonter?
    • solid glass w. chemical reaction on surface to make permanent record of observation.
    • improved by using larger telescopes and shorter wavelengths.
    • smeared out image of a star in long duration exposure
    • lights at different telescopes and slight different times
  32. infrared telescopes
    • sensitive to longer wavelength radiation, absorbed by atmosphere, not reflect on mirror, SEE THROUGH DUST.
  33. X ray telescope
    • High energy telescope b/c reflected easily by any kind of surface.