Galaxies, Stars, HR Diagram and Black Holes

Question 1

Rotation Curve

Answer 1

a graph of the orbital velocity of stars at various orbital radii in the galaxy

Question 2

Dark Halo

Answer 2

unseen matter that lies in the extended halo

Question 3

Giant Elliptical Galaxy

Answer 3

collision of multiple galaxies– in the center

Question 4

Active Galactic Nuclei

Answer 4

class of galaxies with extremely bright centers which emit light in radio,x-ray, optical and even gamma rays

Question 5

What are the three properties of black holes?

Answer 5

mass, spin and charge

Question 6

Quasars

Answer 6

luminous active galactic nuclei, located in the very distant galaxies

Question 7

What would happen if you replace our sun with a black hole?

Answer 7

nothing, it would just be dark

Question 8

disk component

Answer 8

consists of all matter confined to plane of rotation

Question 9

A globular cluster

Answer 9

smal, spherical clusters of the OLDEST stars

Question 10

the central bulge

Question 11

nucleus

Answer 11

the most mysterious region

Question 12

dark matter

Answer 12

difficult to detect and hard to explain

Question 13

What are the four types of nubluae

Answer 13

1. emission nebulae, 2. planetary nebulae, 3. supernova nebulae, 4. dark nebulae

Question 14

orion nebula

Answer 14

emission nebula and star formation

Question 15

molecular cloud

Answer 15

a large cloud full of molecular gas in ammonia and alcohol

Question 16

stellar clusters

Answer 16

home to emission nebulae

Question 17

open clusters

Answer 17

few hundred stars and home to the youngest stars

Question 18

visual binary

Answer 18

one star orbits another

Question 19

What do binary stars help estimate?

Answer 19

the mass of stars

Question 20

Spectroscopic binary

Answer 20

indirectly measure the orbits using the doppler shift

Question 21

eclipsing binary

Answer 21

a dip in the light of one star as the other pass in front and behind

Question 22

What spectra are the star classified by?

Answer 22

O,B,A,F,G,K,M

Question 23

Spiral Galaxies

Answer 23

hot, bright, stars- luminous and easy to see

Question 24

Barred Spiral Galaxies

Answer 24

an elongated nucleus

Question 25

Flocculant Spiral Galaxy

Answer 25

have a spiral pattern but not a clear set of spiral arms

Question 26

what are the steps to how a galaxy forms?

Answer 26

1. collapse
2. globular clusters form
3. gas and dust settle in a plane
4. stars form in disk

Question 27

singularity

Answer 27

the point where all the mass is squished together

Question 28

event horizon

Answer 28

the ‘surface’ of a black hole; matter passing this boundary is trapped forever

Question 29

radiation core

Answer 29

twin jets of particles and light streaming from the inner edge of the black holes accretion disk

Question 30

accretion disk

Answer 30

a flat, spinning donut of hot gas swirling around and into a black hole