Card Set Information
1. What perception of the Milky Way Galaxy did astronomers have
at the beginning of last century?
2. Which is the correct
description of the Sun's location within the Milky Way?
8 kiloparseces from galactic center, minor spiral arms
3. Measuring which two
quantities of our galaxy allow for a determination (calculation) of
the Milky Way's mass?
(suns orbital velocity) Rotation
speed and distance from the galactic center.
4. 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 for the milky way galaxy shows that there must be
additional unseen matter beyond that radius, that is dark matter
5. Matter belonging to the
Galaxy can be traced out to _______ [what distance] from the center.
6. The object located at the center of the Galaxy is calculated and
predicted to be a ________.
7. All RR Lyrae stars have about the same ___
luminosity of 100 suns
8. With respect to age, the stars in the Galactic disk are ____
9.The Sun's motion in our galaxy
is in a(n) ________orbit.
10. Our solar system lives in the Milky Way's
minor spiral arms
11. The nearest major galaxy to the Milky Way is the________galaxy
12. To determine a Cepheid variable's distance, one must measure
13. The rotation curve for our galaxy
(speed vs distance from center) is ______, compared to the
"Keplerian curve", at large distance from the center.
14. Most of the mass of the Milky Way is predicted to exist in the form of _______
15. The interstellar ______ absorbs light from stars
and makes them appear fainter than they otherwise would appear.
gas or dust
16. The fuzzy band across the sky which we call the Milky Way is actually the light from millions of stars in the ______ component of the Galaxy.
17. Neutral hydrogen gas, bright young O and B stars, Cepheid variable stars, and emission nebulae all map out the position of the ______, in the Milky Way.
18.The Sun is currently
estimated to be about ______ from the center of the Galaxy.
The sun is 8 kiloparsecs
from the center .
248,000 million million
152,000 million million
million kilometers, 19 million million miles, 3.26 light-years.
19. The age of our galaxy is estimated by determining the ages of the
oldest objects in the _
20. Variable stars are stars
whose ______ varies with time.
21. Which of the following
types of galaxies is not one of the Hubble types of galaxy?
Irregular Lrr galaxy, active
galaxy, dwarf galaxy.
22. Which type of galaxy has a
stellar disk but without gas or dust?
So, spiral galaxy
23. Elliptical galaxies tend to contain _____ stars and lack______
x ray halo of hot gas, spiral structure
24. A spiral galaxy whose central region is a bright, bar-like source of light is called a(n) ______ galaxy.
25. When two galaxies move very
closely to each other, their ______ may dramatically
rearrange their visible structures.
26. Giant elliptical galaxies
may be the result of _
the collision of two galaxies
28. Irregular galaxies, in size,
tend to be _______ than spiral galaxies.
29. When galaxies collide, the individual
stars, generally, do not collide. (True/False)
30. The Hubble Ultra Deep field is data from
galaxies that are _____ .
31. Galaxies evolve by __
mergers and interactions.
32. In terms of luminosity, quasars are _
27.Going from galaxy type Sa, to Sb, to Sc, there
is a decline in the size of the galaxy's _______.
33. Star formation in the earliest galaxies of
the universe was ____ .
34. Galaxies at high redshift
(i.e. great distances, or equivalently, younger) are___ compared to low redshift
galaxies (nearby and older).