Ch. 12 Study Questions
1.
What is the measured parallax of stars used for?
Measured parallax is used to find distance to neighboring stars.
2.
Which is brighter, magnitude 5 or magnitude 0?
Magnitude 0 is brighter than magnitude 5.
3.
What two things does a star’s apparent magnitude depend on?
A stars apparent magnitude depends on its brightness and distance from Earth.
4.
What one thing does a star’s absolute magnitude depend on?
The one thing that a star’s absolute magnitude depends on is its brightness.
5.
What is a star’s luminosity?
A star’s luminosity is electromagnetic power that a star releases.
6.
Why are stars different colors?
Stars are different colors because they have different temperatures.
7.
What physical property of a star is reflected by spectral type?
A star’s temperature is reflected by spectral type.
8.
What physical property of a star is reflected by luminosity class?
The physical property of a star reflected by luminosity class is a star’s brightness and density.
9.
What two quantities are plotted on the axes of the HR diagram?
The two quantities that are plotted on the axes of the HR diagram are serface temperatures and
brightness.
10. What do astronomers observe in order to tell if a star is Main Sequence, or one of
the evolved giants?
When determining whether a star is an evolved giant or a Main Sequence star, astronomers
observe the star's radius, brightness, and surface temperature.
