Brock University. Test 1, October 2017 Number of pages: 9 Course: ASTR 1P01, Section 1 Number of Students: 470 Date of Examination: October 3, 2017

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1 Brock University Test 1, October 2017 Number of pages: 9 Course: ASTR 1P01, Section 1 Number of Students: 470 Date of Examination: October 3, 2017 Number of hours: 50 min Time of Examination: 17:00 17:50 Instructor: B.Mitrović 1. During May the constellation Cancer is visible near the Western Horizon. However in June the Cancer is no longer visible in the night sky. The reason for that is that (a) the Earth has rotational axis tipped by 23.5 relative to the vertical to the ecliptic. (b) the Earth is revolving around the Sun. (c) the Earth is spinning about North-South axis. (d) [None of the above.] 2. Vega is the brightest star in the constellation Lyra and the second brightest star in the northern hemisphere. Its distance from us is 25 light-years (ly). How long does it take light emitted by Vega to travel this distance? (a) 2,500 years. (b) 250 years. (c) 25 years. (d) 2.5 years. 3. The average distance between the Earth and the Sun is about (a) 1.5 million km. (b) 15 million km. (c) 150 million km. (d) 1.5 billion km. 4. The angular displacement of stars resulting from their annual motion, i.e. because of the Earth s revolution around the Sun, is about (a) 1 per day. (b) 1 per hour. (c) 1 per minute. (d) 1 per second. 5. If the Earth was rotating (spinning) from East to West as observed from above the North Pole, the stars and the Sun would rise in the West and set in the East. 1

2 Course: ASTR1P01 Date: October 3, 2017 page 2 of 9 pages 6. Which of these planets is closest to the Sun? (a) Mercury. (b) Venus. (c) Earth. (d) Mars. 7. The Andromeda Galaxy 2.5 million light years away is the most distant object easily seen by the unaided eye. How long does it take light produced by its stars to reach the Earth. (a) 25 million years. (b) 2.5 million years. (c) 2,500 years. (d) 2.5 years. 8. Over time the Moon is (a) slowly drifting away from the Earth. (b) at a constant distance from the Earth. (c) slowly approaching the Earth. 9. The Milky Way belongs to a cluster of galaxies called (a) Oort cloud. (b) Milky Way cluster. (c) Local group. (d) Kuiper belt. 10. In their daily motions the Sun and the stars appear to be moving parallel to celestial equator because (a) the Earth is revolving around the Sun. (b) the Earth s rotational axis is perpendicular to the equatorial plane. (c) the Earth is rotating (spinning) from West to East. (d) [The statement is wrong. In their daily motions the Sun and the stars appear to be moving parallel to the ecliptic] 2

3 Course: ASTR1P01 Date: October 3, 2017 page 3 of 9 pages 11. Suppose that you are not very familiar with the stars and constellations, but you notice that the circumpolar stars which you observe move counterclockwise. Then you must be located in the (a) southern hemisphere. (b) northern hemisphere. (c) [No definite statement can be made.] 12. How can one locate the north celestial pole at the present time? (a) By locating the star in the middle of Cassiopeia. (b) By locating the star in the middle of Cygnus (Northern Cross). (c) By locating the star which is at the end of the handle of the Big Dipper. (d) By locating the star which is at the end of the handle of the Little Dipper. 13. For an observer on the equator (a) no star is a circumpolar star. (b) all stars are circumpolar stars. (c) about 50% of stars are circumpolar and the rest of the stars rise and set. (d) [No statement can be made without knowing the longitude of the observer.] 14. If a star rises tonight at 10:15 pm, yesterday it rose at about (a) 10:15 pm. (b) 10:19 pm. (c) 10:11 pm. 15. The Milky Way Galaxy and the Andromeda galaxy are (a) approaching each other. (b) receding from each other. 16. If your celestial horizon coincides with the celestial equator you are located (a) on the equator. (b) at either the North Pole or the South Pole. (c) [No statement can be made.] 3

4 Course: ASTR1P01 Date: October 3, 2017 page 4 of 9 pages 17. If a celestial pole is on your horizon you are located (a) on the equator. (b) at either the North Pole or the South Pole. (c) [No statement can be made.] 18. On Autumnal equinox the Sun is (a) on celestial equator. (b) above celestial equator. (c) below celestial equator. 19. As seen from Ontario in October the Sun (a) rises south of east and sets south of west. (b) rises north of east and sets north of west. (c) rises north of east and sets south of west. (d) rises south of east and sets north of west. 20. As seen from Ontario on winter solstice the Sun is (a) on celestial equator. (b) above celestial equator. (c) below celestial equator. 21. On the day of winter solstice the number of hours of darkness at the latitude 80 North is (a) 0. (b) 12. (c) As seen from Ontario on summer solstice the Sun is (a) above celestial equator. (b) below celestial equator. (c) on celestial equator ,000 years ago the star closest to the north celestial pole was Polaris. 4

5 Course: ASTR1P01 Date: October 3, 2017 page 5 of 9 pages 24. What is the angular displacement of a star in the night sky after 6 hours? (a) 6. (b) 15. (c) 60. (d) 90. For Questions refer to Figure 1. Figure When you are at b) it is (a) sunrise. (b) noon. (c) sunset. (d) midnight. 26. You can observe the waning crescent Moon at sunset. 27. You can observe the waxing gibbous moon at midnight. 5

6 Course: ASTR1P01 Date: October 3, 2017 page 6 of 9 pages 28. The third-quarter Moon sets at (a) sunrise. (b) noon. (c) sunset. (d) midnight. 29. The first-quarter Moon rises at (a) sunrise. (b) noon. (c) sunset. (d) midnight. 30. You can observe the full moon in the morning. 31. When the Moon is at 6) it is waxing gibbous. 32. When you are at c) it is (a) sunrise. (b) noon. (c) sunset. (d) midnight. 33. The precession of the Moon s orbit, and the resulting precession of the line of nodes, (a) has no effect on the dates of the eclipses from year to year. (b) causes the dates of the eclipses to shift by 20 days from year to year. (c) causes the dates of the vernal equinox to shift by 20 days from year to year. (d) [The statement is wrong. The Moon s orbit does not precess.] 6

7 Course: ASTR1P01 Date: October 3, 2017 page 7 of 9 pages 34. The pase of the Moon when a solar eclipse is observed is (a) new moon. (b) full moon. 35. The pase of the Moon when a lunar eclipse is observed is (a) new moon. (b) full moon. 36. How did Aristarchus deduce that the Sun is at a much greater distance than the Moon? (a) From the length of the shadow of an obelisk. (b) By comparing the intervals of time between two quarter phases of the Moon. (c) From the difference in their angular sizes. (d) From Moon s elevation above the ecliptic. 37. What is wider? (a) The Moon s umbra at the surface of the Earth. (b) The Earth s umbra at the location of the Moon. 38. At the time of Aristarchus, the fact that parallax shift of the brighter stars could NOT be seen was considered evidence for which model? (a) The geocentric model. (b) The heliocentric model. 39. Who was the first to observe the precession of equinoxes? (a) Aristotle. (b) Aristarchus. (c) Hipparchus. (d) Erathostenes. 40. The ancient Greeks explained retrograde motion of planets as a result of (a) their motion along epicycles. (b) difference in speeds of the Earth and another planet in their orbits around the Sun. (c) [None of the above.] 7

8 Course: ASTR1P01 Date: October 3, 2017 page 8 of 9 pages 41. Who was the first to determine the radius of the Earth? (a) Aristotle. (b) Aristarchus. (c) Hipparchus. (d) Erathostenes. (e) Omar Khayyam. 42. During a total lunar eclipse the Moon is often observed to be (a) reddish. (b) bluish. 43. Who was the first to determine the length of tropical year to high accuracy? (a) Aristotle. (b) Aristarchus. (c) Hipparchus. (d) Erathostenes. (e) Omar Khayyam. 44. The interval of time between the first quarter moon and the third quarter moon is about one week. 45. The distance between the Sun and the star closest to it is about (a) several light-minutes. (b) several light-days. (c) several light-years. (d) several tens of light-years. 46. The Milky Way is larger in size than the Local Group. 8

9 Course: ASTR1P01 Date: October 3, 2017 page 9 of 9 pages 47. The center of the Milky Way is a source of radio waves which travel through space at the speed of light. How long does it take these waves to reach us here on Earth? (a) About 300 years. (b) About 3,000 years. (c) About 30,000 years. (d) About 300,000 years. 48. The eccentricity of the Earth s orbit does not change over time. 49. The tilt of the Earth s rotational axis (currently ) changes over time. 50. The direction of the Earth s rotational axis does not change its direction relative to the stars. 9