Milky Way
In the future, astronomers believe that the Milky Way Galaxy has additional collisions in store. Which of the following nearby galaxies are eventually going to collide with our own?
...
Which of the following statements about the nuclear bulge of our Galaxy is FALSE?
...
The scientist who made the first telescopic survey of the Milky Way and discovered that it is composed of a huge number of individual stars was
Galileo Galilei
Which occur only in the parts of the Galaxy other than the spiral arms?
Globular cluster, ...
Your weird cousin, who is really into astronomy, decides that the return address he uses on his letters is incomplete! To his city, state, and country, he begins to add: "North America, Earth, Solar System..." If he now wants to include the name of the Galaxy's spiral-structure feature in which the Earth is located, how should his address end?
Orion Spur
The very strong source of radio waves at the center of our Galaxy is called
Sagittarius A
Astronomers today know a lot about the size and shape of the Milky Way Galaxy. Which of the following common objects most resembles the shape of our Galaxy?
a CD or DVD
Objects orbiting around the center of the Milky Way obey Kepler's 3rd Law. This means that:
a cloud of gas or star that is further from the center will generally take more time to orbit
The central region of our Galaxy is not as flat as its main disk of stars. Which of the following has roughly the same shape as our central region of stars?
a peanut
You suddenly get an uncontrollable urge to find out more about the other side of the Milky Way Galaxy (the regions beyond the center). Where should you rush off to? i.e. Which type of emission will more easily make it through all the gas and dust in the galaxy?
a radio telescope that can observe at 21-cm wavelengths
Astronomers now think that there is a black hole with more than 4 million times the mass of our Sun at the center of our Galaxy? Roughly how large would the event horizon of such a supermassive black hole be?
about 35 times the size of the Sun (0.3 AU)
The Population I stars in the Milky Way Galaxy
all of the above
Astronomers now know that surrounding the main body of our Galaxy and our fainter halo of stars there is
an invisible halo made of what astronomers are calling "dark matter"
Which are thought to be very old?
globular cluster, ...
What objects did Harlow Shapley use as "signposts" to figure out the extent of the Milky Way Galaxy and the location of its center?
globular clusters
Which are thought to be very young?
group of O & B stars, open cluster, ...
Which have the hottest stars?
group of O and B stars, young open clusters, some giant molecular clouds (those with stars), planetary nebulae (remember they have a centra stellar core leftover)
If I want to find a sizeable collection of Population II stars in the Milky Way Galaxy, where would be a good place to look?
in a globular cluster high above the Galaxy's disk
Where would you look for the youngest stars in the Milky Way Galaxy?
in the disk
Which occur only in spiral arms?
open clusters, group of O and B, giant molecular cloud
Our Milky Way Galaxy is what type of galaxy?
spiral
Which of the following is NOT part of the growing chain of evidence that makes many astronomers suspect there is a black hole at the very center of the Milky Way Galaxy?
the Hubble Space Telescope has shown us a visible-light image of an accretion disk at the center of the Galaxy
Astronomers believe that the center of our Galaxy has a black hole with enough mass inside to make almost 4 million Suns! How do astronomers think a black hole could acquire so much mass?
the center of our Galaxy is a much more crowded region than where the Sun is found; we still see material falling toward the center and material has fallen in for billions of years
William Herschel thought that the Sun and Earth were roughly at the center of the great grouping of stars we call the Milky Way. Today we know this is not the case. What was a key reason that Herschel did not realize our true position in the Milky Way?
the dust that extends throughout the disk of the Galaxy only allowed Herschel to see the small part of the Milky Way that surrounds us
Recently, astronomers have observed stars and other objects that orbit the center of the Milky Way Galaxy farther out than our Sun, but move around faster than we do. How do astronomers think such an observation can be explained?
there must be a great deal of invisible dark matter outside the orbit of the Sun whose gravitational pull explains the faster motions we see out there
What have we learned from the work of Harlow Shapley and others about the location of the Sun in the Milky Way Galaxy?
we are in the disk of the Galaxy, about 3/5 of the way from the center
