Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 1 If you could hover over the Earth’s north rotational pole and look down at the Earth as it spins, you would see that the Earth spins in a ____________ direction. a) clockwise b) counter-clockwise
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 2 Announcements: Homework #2 due today; Pick up HW #3 Reading: Chp 1: sections 1.2 and 1.3
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 3 Naked-Eye Astronomy Annual Motion Sky Charts
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 4 Review: Celestial Sphere Latitude/Longitude, Zenith/Horizon NCP, SCP; Celestial Equator Diurnal Motion Rising and setting stars from various latitudes Constellations, Asterisms Annual Motion
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6 Observing Astronomical Phenomena Daily: Monthly: Yearly: Other: Objects rise in the East and set in the West. Different constellations visible at different times of year. Moon seen at different “phases”.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 7 Day and Night: The Spinning Earth Virtual planetarium…
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 8 The Rising and Setting Stars Figure 1.4 Virtual planetarium…
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 9 Montreal, Canada, is at a latitude of 45º N and a longitude of 73º W. Which of the following diagrams is an accurate representation of the setting stars: 45º 17º 45º 90º A)B) C)D)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 10 Rising and Setting Stars: Stars only rise perpendicular to the horizon if you happen to be living on the equator In the Northern hemisphere, stars rise inclined toward the south (to the north if you are in the southern hemisphere). At the poles, stars will not rise or set, but circle around you!!
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 11 Constellations change with seasons
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 12 Vocabulary: longitude/latitude celestial sphere celestial pole/equator horizon/zenith constellation ecliptic/zodiac
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 13 Which one of the following is true with regards to the ecliptic? a. The ecliptic traces out the plane of the north and south celestial poles in the sky. b. The ecliptic is defined as the eliptical path of the Earth on the horizon. c. The ecliptic is defined as the intersection of the zodiac with the celestial equator. d. The ecliptic traces out the path of the Sun in the sky over the course of the year.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 14 The rotational axis keeps its same orientation as the Earth orbits the Sun (…at least on short timescale…)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 15 Sky Chart: Date/Time and Latitude determine appearance of Sky Chart.
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 17 1.Which bright star is very nearly overhead (near zenith) at 8:30PM tonight? a)Draco b)Deneb c)Polaris d)Capella
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which bright star is rising in the east at 10:30PM on Valentines Day? a) Polaris b) Spica c) Pollux d) Virgo e) Rigel
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which direction should you face to see Cassiopeia at midnight on April 1st? a) North b) South c) East d) West
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Which of the following sketches shows the correct appearance of the Big Dipper at 5PM on December 5 th ? A)B)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 21 This constellation can be seen on the southern horizon at midnight on June 29 th. a) Bootes b) Libra c) Scorpius d) Sagittarius e) Capricornus
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 22 Angular Size Depends on distance and actual size.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 23 1º1º 10º 20º
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 24 Arm must be straight!