Vocab
The sun and all of the planets and other bodies that travel around it.
Solar system
Which of the following units is used to express the size of stars?
A. kilometer
B. light-year
C. solar radius
D. astronomical unit
C. solar radius
Galaxies are large groups of millions, billions, or even trillions of stars. What would you claim keeps the stars in a galaxy from moving away from each other?
A. gravity
B. density
C. composition
D. temperature
A. Gravity
Which of the following is larger than a galaxy?
A. a star C. the universe
B. a planet D. a solar system
c. the universe
the distance that light travels in one year; ~9.46 trillion kilometers
light-year
A relatively large spherical body that orbits a star.
Planet
Which statement best describes stars?
A. large planets that are composed mostly of gases
B. celestial bodies made up of gas that give off light
C. faint dots of light that can be seen from Earth’s surface
D. objects that form in the outer parts of the solar system
B. celestial bodies made up of gas that give off light
Our solar system consists of eight planets. Which phrase correctly describes a planet?
A. a large celestial body that is composed of gas and emits light
B. any one of the primary bodies that orbits a star
C. many stars held together by gravity
D. space and all the matter and energy in it
B. any one of the primary bodies that orbits a star
When we say an object is in orbit, we mean that it is traveling around another object in space. What do planets in a solar system orbit?
A. a star C. a galaxy
B. a moon D. a universe
a. A star
A collection of stars, dust and gas bound together by gravity
Galaxy
A large celestial body that is composed of gas and that emits light; the sun is a typical star
Star-
Two stars have the same apparent magnitude as seen from Earth’s surface. Star A is 33 ly away. Star B is 346 ly away. Which of the following claims is supported by the evidence?
A. Star B is larger than star A.
B. Star B is more luminous than star A.
C. The stars have the same absolute magnitude.
D. Star A has a smaller absolute magnitude.
B. Star B is more luminous than star A.
A light-year (ly) is the distance that light travels in one year. Based on this evidence, if a star is 3 ly from Earth, how long does it take light from that star to reach Earth?
A. 3 min
B. 3 h
C. 3 y
D. 3 ly
3 y
When designing technology, designers must consider factors that limit the design. What are these factors called?
A. trade-offs C. prototypes
B. constraints D. methodical thinking
A. trade-offs
space and all the matter and energy in it
Universe
The brightness of a star as seen from Earth.
Apparent magnitude-
Which of the following statements best describes a binary star system?
A. A star appears blue in the night sky.
B. A star is orbited by a gas giant planet.
C. Two pairs of stars orbit each other.
D. Two stars orbit each other.
D. Two stars orbit each other.
Celestial bodies can be classified based on their sizes. Which of the following is the smallest?
A. a planet
B. the sun
C. a red supergiant star
D. a red giant star
A planet
Scientists often use visual or mathematical representations to investigate items that are very large, very small, or otherwise difficult to study. What are these visual or mathematical representations called?
A. experiments
B. hypotheses
C. models
D. observations
C. models
The actual brightness of an object such as a star
Luminosity
Is a measure of how bright a star would be if it were seen from a standard distance
absolute magnitude
Identifying the independent and dependent variables in an experiment will help you better interpret and convey results. What is the difference between the independent and dependent variables in an experiment?
A. The independent variable is always a number, and the dependent variable is never a number.
B. The independent variable is what you control, and the dependent variable is what changes as a result.
C. The dependent variable is what the investigator controls, and the independent variable is what happens as a result of this.
D. The dependent variable is typically found in the first column of a table, and the independent variable is typically found in the second column.
B. The independent variable is what you control, and the dependent variable is what changes as a result.