Astronomy 1345 Exam 1 UTA With Complete Solution

If there are about 6000 stars in the entire sky that can be seen by the unaided human eye, about how many stars would be seen at a particular instant on a given dark night from a single location with an uninterrupted distant horizon? - ANSWER 3000 Are the constellations seasonal? - ANSWER Yes. On a summer night many of the constellations you can see are different from the constellations you can see on a winter night. But there are some constellations you can see all year long. In modern astronomy, the constellations are - ANSWER 88 nonoverlapping sky regions, covering the whole sky. The constellations - ANSWER are 88 in number and cover the entire sky. Which of the following statements correctly describes the relationship between stars and constellations? - ANSWER Every star is located in a constellation. Over what typical time scale will the particular pattern of stars in a specific constellation appear to change from our view on Earth because of celestial motions? - ANSWER thousands of years because of motions of individual stars How much of the overall sky is north of the celestial equator? - ANSWER exactly one-half The zero point of the celestial coordinate known as right ascension (RA) is defined to be the - ANSWER point where the Sun crosses the celestial equator moving northward in its path across the sky. The angle between an observer's horizon and the north celestial pole is governed by- ANSWER latitude The celestial equator is defined as the - ANSWER line in the sky that is perpendicular to Earth's spin axis. An arc second is a measure of - ANSWER angle Which way are you moving with respect to the stars because of the rotation of the Earth? - ANSWER eastward The most easily observed motions in the night sky are produced by the - ANSWER rotation of the Earth on its axis When we watch the nighttime sky, we find that - ANSWER most stars and constellations slowly rise in the east and set in the west. The ecliptic can be defined as the - ANSWER path traced out by the Sun in our sky over one year against the background stars If we could watch the Sun moving day by day against the background stars, it would follow - ANSWER the ecliptic The ecliptic crosses the celestial equator - ANSWER at two points, known as equinoxes The tilt angle of the Earth's spin axis to the direction perpendicular to the ecliptic (known as the ecliptic pole) - ANSWER is 23.5° and fixed The Earth would NOT have seasons if - ANSWER its axis of rotation were perpendicular to its orbital plane. Summertime in the northern hemisphere is when the - ANSWER northern hemisphere is tilted toward the Sun When the northern hemisphere is experiencing winter, the - ANSWER Earth is closer to the Sun than it is during northern summer