AST2002- Exam 3 UCF Study Guide
Exam and All Correct Answers 2025-
2026 Updated.
three main components of the galaxy - Answer disk, bulge, halo
where are globular clusters found - Answer halo
what are pop 1 stars - Answer young, metal rich stars
what are pop 2 stars - Answer old, metal poor stars
what pop are the stars in the halo - Answer pop 2, old
what pop are the stars in the disk - Answer pop 1, young
what is the orbital motion of the halo - Answer random, circular movements that go higher
and lower than the disk
what is the orbital motion of the bulge - Answer random, circular movements
what is the orbital motion of the disk - Answer stays on the same orientation/path with a
little bit of up and down motion, flat
what percent of the universe is regular matter - Answer 5%
what percent of the universe is dark matter - Answer 27%
what percent of the universe is dark energy - Answer 68%
what are globular clusters - Answer tightly knit clusters of old stars
what does the saying red is dead mean in this context - Answer they are done producing
new, hot blue stars and only have old stars
, why do we think there is a super massive black hole at the center of our galaxy - Answer
stars orbit something huge and invisible at the center, strong radio and xray emission
what does blue indicate about star formation of a galaxy - Answer ongoing, hot star
formation
what is dark matter - Answer glue that holds universe together, emits reflects and absorbs
no light so it is invisible to telescopes, has gravity
what is dark energy - Answer unknown energy causing expansion and acceleration of the
universe
why can't we see before t=380,000 years - Answer too hot and dense, photons couldn't get
through
what is the cosmic microwave background - Answer oldest detectable light in the universe,
380,000 years
spiral galaxies - Answer flat with a central bulge and arms, bluer in color, new star formation
elliptical galaxies - Answer 3d shapes, little to no star formation, red because of small
amount of gas
irregular galaxies - Answer chaotic and assymetric, lots of new star formation and lots of gas,
blue in color
which galaxy type is the suburbs and why - Answer spiral because they are in groups
which galaxy type is the big city and why - Answer elliptical because they are in big clusters
major merger - Answer two spiral galaxies come together to form an elliptical, lose their
arms
minor merger - Answer when a smaller galaxy merges with a larger one to make a large
spiral
how does star formation work - Answer dust and gas compressed together anywhere cold,
dark and dense
Exam and All Correct Answers 2025-
2026 Updated.
three main components of the galaxy - Answer disk, bulge, halo
where are globular clusters found - Answer halo
what are pop 1 stars - Answer young, metal rich stars
what are pop 2 stars - Answer old, metal poor stars
what pop are the stars in the halo - Answer pop 2, old
what pop are the stars in the disk - Answer pop 1, young
what is the orbital motion of the halo - Answer random, circular movements that go higher
and lower than the disk
what is the orbital motion of the bulge - Answer random, circular movements
what is the orbital motion of the disk - Answer stays on the same orientation/path with a
little bit of up and down motion, flat
what percent of the universe is regular matter - Answer 5%
what percent of the universe is dark matter - Answer 27%
what percent of the universe is dark energy - Answer 68%
what are globular clusters - Answer tightly knit clusters of old stars
what does the saying red is dead mean in this context - Answer they are done producing
new, hot blue stars and only have old stars
, why do we think there is a super massive black hole at the center of our galaxy - Answer
stars orbit something huge and invisible at the center, strong radio and xray emission
what does blue indicate about star formation of a galaxy - Answer ongoing, hot star
formation
what is dark matter - Answer glue that holds universe together, emits reflects and absorbs
no light so it is invisible to telescopes, has gravity
what is dark energy - Answer unknown energy causing expansion and acceleration of the
universe
why can't we see before t=380,000 years - Answer too hot and dense, photons couldn't get
through
what is the cosmic microwave background - Answer oldest detectable light in the universe,
380,000 years
spiral galaxies - Answer flat with a central bulge and arms, bluer in color, new star formation
elliptical galaxies - Answer 3d shapes, little to no star formation, red because of small
amount of gas
irregular galaxies - Answer chaotic and assymetric, lots of new star formation and lots of gas,
blue in color
which galaxy type is the suburbs and why - Answer spiral because they are in groups
which galaxy type is the big city and why - Answer elliptical because they are in big clusters
major merger - Answer two spiral galaxies come together to form an elliptical, lose their
arms
minor merger - Answer when a smaller galaxy merges with a larger one to make a large
spiral
how does star formation work - Answer dust and gas compressed together anywhere cold,
dark and dense
