unit 8

Question 1

The star’s apparent motion
- a star’s position once, then again 6 months later

Answer 1

stellar parallax

Question 2

distance that light travels in one year

Answer 2

light year

Question 3

a unit of length or distance
- used to measure the large distances to astronomical objects outside the Solar System

Answer 3

parsec

Question 4

any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources

Answer 4

star

Question 5

a measure of the total amount of energy radiated by a star or other celestial object per second

Answer 5

luminosity

Question 6

• depends on its its distance from Earth
• the total energy emitted by a star per second
• how bright a star appears from the perspective of observers on Earth

Answer 6

apparent brightness

Question 7

a number that tells how bright that star appears at its great distance from Earth

Answer 7

apparent magnitude

Question 8

the magnitude that a star would appear to have if it were located at a standard distance of 10 parsecs

Answer 8

absolute magnitude

Question 9

the relationship between the stars’ absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

Answer 9

HR diagram

Question 10

an enormous cloud of dust and gas occupying the space between stars and acting as a nursery for new stars.

Answer 10

nebula

Question 11

looks like a star but its core is not yet hot enough for fusion to take place

Answer 11

prostar

Question 12

fuse hydrogen to form helium in their cores - including our Sun.

Answer 12

main sequence stars

Question 13

• when main sequence stars run out of hydrogen fuel
• dying stars
• the most massive and most luminous stars

Answer 13

supergiants and giant stars

Question 14

• blue/white core of the star that is left behind
• a small very dense star that is typically the size of a planet.
• dead main sequence stars
• hot and dim

Answer 14

white dwarfs

Question 15

a white dwarf that has cooled sufficiently to no longer emit significant heat or light

Answer 15

black dwarfs

Question 16

• remain of high mass stars
• form by the gravitational collapse of the remnant of a massive star after a supernova explosion

Answer 16

neutron stars

Question 17

• formed from massive stars
• an area of such immense gravity that nothing—not even light—can escape from it

Answer 17

black holes

Question 18

if you know the apparent brightness and luminosity can you find the distance

Answer 18

True

Question 19

objects farther away will have a ______ parallax

Answer 19

smaller

Question 20

objects closer will have a ______ parallax

Answer 20

larger

Question 21

which covers a larger distance, 1 light year or parsec

Answer 21

1 parsec

Question 22

Which Greek Philosopher invented a system of Magnitudes for the brightness of stars?

Answer 22

Hippaechus

Question 23

True or False

Objects with a negative magnitude appear brighter than objects with a negative magnitude?

Answer 23

True

Question 24

where on the main sequence does a HIGH mass star begin

Answer 24

upper left hand corner

Question 25

where on the main sequence does a LOW mass star begin

Answer 25

lower right hand corner

Question 26

where on the main sequence does a sun like star begin?

Answer 26

the middle

Question 27

how does the initial mass of the protostar affect a star’s evolution?

Answer 27

The more massive the star, the faster everything happens