Notes 4 Exam Flashcards
What perception of the Milky Way Galaxy did astronomers have at the beginning of last century?
They believed that the Milky Way was the entire universe.
Which is the correct description of the Sun’s location within the Milky Way?
right side of the galactic bulge
8 kpc from it.
Measuring which two quantities of our galaxy allow for a determination (calculation) of the Milky Way’s mass?
kiloparsec and parsec
What observation of the Galaxy suggests that it is much larger than the halo component, and that it contains a large amount of matter not in the form of stars?
The rotation curve
Matter belonging to the Galaxy can be traced out to _______ [what distance] from the center.
15kpc
The object located at the center of the Galaxy is calculated and predicted to be a ________.
Galactic bulge
All RR Lyrae stars have about the same ___ .
luminosity of about 100 suns
With respect to age, the stars in the Galactic disk are ____ .
young compared to stars in the galactic halo
The Sun’s motion in our galaxy is in a(n) ______ orbit.
ellipse
Our solar system lives in the Milky Way’s ____ .
The sun is about 26,000 light-years from the center of the Milky Way Galaxy
The nearest major galaxy to the Milky Way is the ____ galaxy.
Andromeda
To determine a Cepheid variable’s distance, one must measure its ___.
The apparent brightness. Also, the period of the star, which is related to its real brightness.
The rotation curve for our galaxy (speed vs distance from center) is _________, compared to the “Keplerian curve”, at large distance from the center.
higher
Most of the mass of the Milky Way is predicted to exist in the form of ___ .
dark matter
The interstellar ______ absorbs light from stars and makes them appear fainter than they otherwise would appear.
gas or dust
