ASTR100 UMD Final Exam Review with All Correct &
100% Verified Answers |Latest Update| Already
Graded A+
Milky Way ✔Correct Answer--The spiral galaxy where our solar system is located
Galaxy ✔Correct Answer--A great island of stars in space
Spiral Galaxy ✔Correct Answer--A galaxy that looks like a flat disk with a bright bulge in the center.
Also characterized by the bright spiral arms that go around it
Parts of A Spiral Galaxy ✔Correct Answer--1. Bulge
2. Disk
3. Spiral Arms
4. Halo
Bulge ✔Correct Answer--the center of a spiral galaxy that is football shaped. Objects near it orbit in
a 3-D, random pattern
Disk ✔Correct Answer--portion of spiral galaxy that looks like a disk. Contains interstellar medium
with cool gas and dust. Stars of all ages live here. Objects in the disk all orbit in the same plane
Spiral arms ✔Correct Answer--Bright arms in a spiral galaxy where star formation usually occurs
Halo ✔Correct Answer--A spherical area around a spiral galaxy that is nearly invisible except for
globular clusters of stars. Objects in the halo orbit in a random 3-D motion(Think of the halo as the
ort cloud around the sun, except it is with stars and galaxies).
Interstellar medium ✔Correct Answer--The term used for interstellar gas and dust collectively. This
obscures our view when we try and look through it. Also provides raw material for which stars are
formed.
Star-gas-star cycle ✔Correct Answer--The way in which gas from old stars is recycled into new star
systems.
Atomic hydrogen gas ✔Correct Answer--gas that forms when a hot gas cools, and allows electrons
to join with protons
Molecular clouds ✔Correct Answer--These form after atomic hydrogen gas cools enough to allow
atoms to combine into molecules.
Ionization Nebulae ✔Correct Answer--A colorful cloud of gas that glows because neighboring hot
stars irradiate it with UV photons that ionize hydrogen atoms.
How did the Milky Way form ✔Correct Answer--1. Started with a cloud of interstellar gas
(Protogalactic cloud)
2. Halo stars form as gravity causes gas to contract
3. Gas settles into a spinning disk
100% Verified Answers |Latest Update| Already
Graded A+
Milky Way ✔Correct Answer--The spiral galaxy where our solar system is located
Galaxy ✔Correct Answer--A great island of stars in space
Spiral Galaxy ✔Correct Answer--A galaxy that looks like a flat disk with a bright bulge in the center.
Also characterized by the bright spiral arms that go around it
Parts of A Spiral Galaxy ✔Correct Answer--1. Bulge
2. Disk
3. Spiral Arms
4. Halo
Bulge ✔Correct Answer--the center of a spiral galaxy that is football shaped. Objects near it orbit in
a 3-D, random pattern
Disk ✔Correct Answer--portion of spiral galaxy that looks like a disk. Contains interstellar medium
with cool gas and dust. Stars of all ages live here. Objects in the disk all orbit in the same plane
Spiral arms ✔Correct Answer--Bright arms in a spiral galaxy where star formation usually occurs
Halo ✔Correct Answer--A spherical area around a spiral galaxy that is nearly invisible except for
globular clusters of stars. Objects in the halo orbit in a random 3-D motion(Think of the halo as the
ort cloud around the sun, except it is with stars and galaxies).
Interstellar medium ✔Correct Answer--The term used for interstellar gas and dust collectively. This
obscures our view when we try and look through it. Also provides raw material for which stars are
formed.
Star-gas-star cycle ✔Correct Answer--The way in which gas from old stars is recycled into new star
systems.
Atomic hydrogen gas ✔Correct Answer--gas that forms when a hot gas cools, and allows electrons
to join with protons
Molecular clouds ✔Correct Answer--These form after atomic hydrogen gas cools enough to allow
atoms to combine into molecules.
Ionization Nebulae ✔Correct Answer--A colorful cloud of gas that glows because neighboring hot
stars irradiate it with UV photons that ionize hydrogen atoms.
How did the Milky Way form ✔Correct Answer--1. Started with a cloud of interstellar gas
(Protogalactic cloud)
2. Halo stars form as gravity causes gas to contract
3. Gas settles into a spinning disk
