Astronomy Lecture Notes

  1. Introduce myself
  2. Introduce the course
  3. My Faculty Web page
  4. Syllabus
  5. Daily Schedule – coming soon, maybe even this afternoon
  6. Calculator
  7. Attendance
  8. Class Etiquette
  9. If you arrive late of have to leave early enter and exit via the perimeter of the classroom and do not walk down the center aisle disrupting the flow of the lecture.
  10. Please turn your cell phones off or tell me ahead of time that you cannot turn them off because you are expecting an important call.
  11. If you text or surf the web during class, you might as well stay home. Please don’t do it. I’ll ask you to leave if your texting distracts me or other students.
  12. How to succeed in this course (The Hand)
  13. Attend
  14. Come Ready to Learn
  15. Practice Good Study Habits
  16. Pay Attention to Details
  17. Believe in the Value of What you are Learning
  18. I have added two short video links in Hot Tips
  19. Powers of Ten
  20. AMNH The Known Universe.
  21. Watch them. We’ll talk next class.
  22. The first HW Assignment
  23. Show’em where it is.
  24. Show’em how to answer the questions in Word.
  25. Due next Tuesday/Wednesday.
  26. Math Review
  27. How many of you own a scientific (EE or Exp button) calculator?
  28. How many of you brought them with you today?
  29. Scientific notation review
  30. Examples of important numbers
  31. Distance to the Sun is 150,000,000 m
  32. One light year is 9,460,528,400,000,000 m
  33. Distance to the center of our galaxy 264,894,795,200,000,000,000 m
  34. First, round off each to 3 significant figures – class rule, no numbers past three significant figures.
  35. Second, write each number in scientific notation.
  36. Compare the expressions.
  37. Important forms: 103 is a thousand, 106 is a million, 109 is a billion, and 1012 is a trillion
  38. Show them how to enter scientific notation on the calculator
  39. Tutorial on scientific notation from the Kahn Academy
  40. Plus other Kahn Academy tutorials in the Scientific notation series
  41. Simple metric system review
  42. We will be using the “mks” system where “mks” stands for meters-kilograms-seconds”
  43. Rules of thumb
  44. 1 meter is about one yard (about three inches longer really)
  45. 1 kilometer is about 60% of a mile
  46. 1 kilogram is equivalent to the weight of a medium apple or about 2 pounds.
  47. Only length conversions
  48. Convert the distance to the Sun into km
  49. Convert 4.3 ly into km (1 ly = 9.461015m)
  50. Convert the distance to the center of the galaxy into lys.
  51. Tutorial on metric conversions from the Kahn Academy
  52. Ratios and Proportions
  53. Whenever a problem asks you to “compare” two things a ratio is appropriate. Note units cancel in ratios.
  54. How does the distance to the Moon compare to the radius of the Earth?
  55. How does the distance to the nearest star compare to the distance of the Earth from the Sun?
  56. Scale problems require a proportion. Extra-credit opportunity on HOT TIPS
  57. “If the diameter of the Earth was 1 foot, how far away would the Moon be?”
  58. “If the diameter of the Earth was 1 foot, how far away would the Sun be?”
  59. “If the diameter of the Earth was 1 foot, how far away would the Proxima Centauri be?”
  60. “If the diameter of the Earth was 1 foot, how far away would the center of the galaxy be?”
  61. See the APOD for Monday, Aug 25
  62. We’ll be doing other type problems, but the algebra will be no more difficult that a proportions (almost).
  63. The Apparent Motion of the Stars
  64. Stars over Greece Video 2011 May 04
  65. Why should you be interested in the apparent motions of the stars?
  66. Navigation
  67. Ottawa Story: Big Dipper out the passenger window
  68. Skaneateles Story: Rising Sun out the passenger window
  69. Knowing your directions in the daytime: The Sun is always in the south during the day, except very close to sun rise or set
  70. Makes you more aware of the cycles of nature.
  71. How can we explain these motions?
  72. The Celestial Sphere Model or The Two Sphere Model of the Universe
  73. Textbook reading Chapter 3 Astronomy Without a Telescope, pg. 27 to 35
  74. The figures are VERY important!!
  75. Read the text CAREFULLY – it is full of single sentences that will reinforce what I tell you in class.
  76. Angles
  77. Degrees, Arcminutes and Arcseconds
  78. Rules of Thumb: Very rough (See figure)
  79. Width of your thumb at arm’s length  1degree
  80. Width of your spread fingers (little to thumb) at arm’s length  20 degrees
  81. Note: Full Moon and Sun are each about 0.5 degrees wide. You can cover them with your thumb.
  82. Altitude and Azimuth
  83. Reference Markers
  84. Celestial “geography”
  85. NCP, SCP
  86. Celestial Equator
  87. Meridian, Zenith and Nadir
  88. Celestial Coordinates
  89. Declination and Right Ascension
  90. Read Aristotle’s Description of the Universe
  91. UNL The Rotating Sky and the Rules
  92. See the UNL Rotating Sky Web Site.
  93. Stars appear to revolve ccw around the NCP and cw around the SCP once every 23h 56m 4.09s
  94. The altitude of the NCP equals the observer’s latitude.
  95. All stars revolve on paths parallel to the celestial equator.
  96. The Celestial equator intersects the horizon exactly due East and due West for all observers.
  97. The Celestial Equator rises and sets at a slant angle from the vertical equal to the observer’s latitude.
  98. For Northern observers,
  99. Stars in the northern part of the sky are above the horizon for more than 12 hours a day (some for 24 hours – circumpolar stars).
  100. Stars near the Celestial Equator are above the horizon for about 12 hours a day.
  101. Stars in the southern part of the sky are above the horizon for less than 12 hours a day (some never rise – also called circumpolar stars – this is kind of confusing, even to me, that there are two types of circumpolar stars – those that never set and those that never rise).
  102. Demonstrate using Starry Night.
  103. The simple 2-D Celestial Sphere Diagram: Where will objects be in the sky?
  104. A simple diagram that will help you answer difficult questions
  105. Questions like
  106. “What is the declination of the star at the zenith?”
  107. “What is the maximum altitude of a star as it transits the meridian?”
  108. “What is the declination boundary of the circumpolar regions?”
  109. Show them the diagram
  110. For an observer in Syracuse, NY
  111. For an observer at the North Pole
  112. For an observer at the Equator
  113. Offer an extra-credit assignment for a similar diagram…