Chapter 23

The Milky Way is simply our edge-on view of our home Galaxy

Shapley found the Sun is located about halfway out the disk from the center of the disk of the Galaxy.

As Curtiss thought, our Milky Way is now known to be quite similar to the nearby Andromeda Galaxy, M-31.

Shapley correctly argued that the rotation of the spiral nebulae proved they could not be very distant.

Population I stars came billions of years before Population II stars.

In our vicinity, the galactic disk is about 100 times wider than it is thick.

Spiral arms are regions of star formation, which accounts for their blue color.

It is harder to map the structure of the Milky Way as a whole in visible light than with any other form of electromagnetic radiation.

The rotation curve for our Galaxy shows stars beyond the Sun moving slower than expected.

The majority of the mass of the Milky Way lies farther out than the Sun's orbit.

The core of the Milky Way, Sagittarius A, is a strong radio source in the sky.

The Earth lies close to the center of the Galaxy.

Motions of objects near our Galaxy's core suggest the central black hole is about 3.7 billion solar masses.

From the center of the Milky Way, 10- kpc-long magnetized jets of high-energy particles are emitted.

The center of the Milky Way lies in the direction of the constellation Cygnus

William Herschel's original model for our Galaxy was based on counting stars.

Shapley found that globular clusters are only found in the Galactic bulge.

A pulsating variable star with a period of 10 days would be a Cepheid.

The instability strip includes many main sequence stars.

Henrietta Leavitt first showed the relationship between the mass and luminosity of Cepheids and their period of pulsation; the brighter, the longer this period

RR Lyrae stars pulsate, but with shorter periods and lower luminosities than Cepheids.

In structure, our Milky Way is most similar to:

Which two classes of objects were critical to the Shapley-Curtiss Debate of 1920?

The region on the H-R diagram where pulsating variables occur is called the:

What is one of the differences between Cepheids and RR Lyrae variables?

Harlow Shapley found the Milky Way was:

Galactic disks appear blue because:

Both RR Lyrae and Cepheid variable stars are stars that, when on the main sequence, were considered to be:

What perception of the Milky Way Galaxy did astronomers have in 1900?

All RR Lyrae stars have about the same:

The RR Lyrae stars all have periods of:

Which of the following are most massive and luminous?

The part of the Milky Way we are most familiar with is the:

A star in the instability strip of the H-R diagram would:

The first attempt to map the Galaxy via star counts was done by:

The period-luminosity relation for Cepheid variables was discovered in 1908 by:

Why was Herschel's strategy for mapping our Galaxy flawed?

Most of the new star formation in the Galaxy is found in the:

Matter belonging to the Galaxy can be traced out to ________ from the center.

The orbits of Population II stars have been compared to:

Which of these objects have NOT been found in the Galactic Halo?

For what type of object is the period-luminosity relation used for determining distances?

From the Sun, the distance to the Galactic Center is about:

The Galactic Year is the time for our solar system to orbit the Galaxy; it is about:

Detailed measurements of the disk and central bulge region of our Galaxy suggest our Milky Way is a:

Which is the correct description for the Sun's location in the Galaxy?

Which of these is NOT typical of the Galaxy's spiral arms?

From Earth, the view of the Milky Way is a thin band of stars across the night sky. The part of the Milky Way galaxy that is described here is the:

In the halo, we do NOT find:

The "aspect ratio" of thickness to width of the galactic disk is about:

Star formation ceased first in the:

In the formation of our Galaxy, the ________ formed first.

Based on star counts, 100 years ago most astronomers thought:

Which sequence of formation by age is correct, oldest to youngest?

What use are 21 cm radio waves to galactic astronomers?

Density waves may explain:

The leading explanation for the existence of spiral arms are:

These objects are no longer considered a good explanation for the dark matter in the halo.

Which of the following is most like the rotation of stars in the disk of the Milky Way?

What two observations allow us to calculate the Galaxy's mass?

What observations suggest the mass of the Galaxy goes much farther out than its visible disc?

Between us and the Galactic Center, the Milky Way has a mass of:

Which method relies on the mass of a dark object revealing its presence?

Early in the 20th century, our galaxy was estimated to be:

Most of the mass of the Milky Way seems to exist in the form of:

Using an orbit size of 8 kpc, and a period of 225 million years, the mass of our Galaxy is found to be closest to:

While yet unproven, the proposed WIMPS would be:

The radio source ________ is located in a place consistent with the center of our Galaxy.

The temperature of the innermost part of the spinning gas near our galaxy's central black hole is:

It was the distribution of ________ that showed Harlow Shapley we were no where near the center of the Milky Way in the 1920s.

The location of the Galactic Center was first found by Harlow Shapley with:

The period-luminosity relation is critical in finding distances with:

.Which is the correct description of the Sun's location within the Milky Way?