astronomy exam 1

About how many stars are in the Milky Way Galaxy? 300 million stars 14 billion stars 200 billion stars 2 trillion stars

200 billion stars

Throughout the semester, we will use angular measurements to describe the positions of astronomical objects. How many degrees are in a full circle? If there are 60 arc minutes in 1 degree, how many arc seconds are in 1 degree? .

360 3600

When a time-lapse image is taken at night, the stars produce circular paths. The following image was taken from the northern hemisphere. What is the stationary star at the center of the image? Polaris Clearly, the longer the time-lapse, the longer the star trails will be. Assuming the star trails make up about 1/8th of a circle, how long was the total time-lapse exposure? 3 hours (Hint: how long does it take for the star trails to make a complete circle?)

Polaris 3 hours

Although distance units can be used to describe any distance, it is important to use the most appropriate measurement units when describing different distances. Which units of measurement would be most appropriate for each of the following distances? The distance from the Sun to Alpha Centauri is best measured in ? The distance from the Earth to Pluto is best measured in ? The distance from Sioux Center to Sioux Falls is best measured in ?

The distance from the Sun to Alpha Centauri is best measured in ly The distance from the Earth to Pluto is best measured in AU The distance from Sioux Center to Sioux Falls is best measured in km

Which of the following statements is correct? It takes billions of light-years to cross the Milky Way Galaxy The nearest star to our Sun is about 4 light-years away. A spacecraft traveling at 1 light-year is faster than one traveling 3,000 miles per hour. There are 365 days in 1 light-year

The nearest star to our Sun is about 4 light-years away.

Suppose an astronomer observes the supernova explosion of a star in the Large Magellanic Cloud, at a distance of 163,000 light-years. At the same time, another astronomer observes a supernova in the Small Magellanic Cloud, at a distance of 200,000 light-years. Which supernova actually occurred first? The supernova in the Small Magellanic Cloud! The supernova in the Large Magellanic Cloud Because they were detected at the same time, both occurred at about the same time.

The supernova in the Small Magellanic Cloud

Which of the following celestial objects do NOT rise in the east and set in the west, as viewed from the Earth? (assume that all of these objects are visible from your location on Earth, and that none of them are circumpolar) galaxies the Sun the Moon stars all of these objects rise in the east and set in the west

all of these objects rise in the east and set in the west

Which of these objects can be found in the Solar System? (choose more than one) star galaxy planet comet planetary nebula

star planet comet

What is the most important factor in causing the seasons on Earth? distance between the Earth and the Stars the 23.5° tilt of the Earth's axis the rate of the Earth's rotation

the 23.5° tilt of the Earth's axis

The Gregorian Calendar was introduced to keep Christian Easter (first Sunday after the full Moon that falls on or after the spring equinox) in the springtime. What is the cause of the 11 minute time difference that triggered the reform? the difference between a sidereal day (23 h 56 min) and a solar day (24 hr) the difference between the tropical year (365.24 day) and the Julian year (365.25 day) the difference between a sidereal month (27.3 day) and a synodic month (29.5) the difference between the Catholic and Orthodox religious calendars

the difference between the tropical year (365.24 day) and the Julian year (365.25 day)

Which of the following units of time is not directly tied to some celestial phenomena? the year the month the week the day

the week