stars-- properties and life cycles

Question 1

luminosity measures the total amount of ____ it radiates per _____

Answer 1

energy / second

Question 2

what does luminosity refer to?

Answer 2

the brightness of stars

Question 3

our sun is assigned a luminosity of __

Answer 3

1

Question 4

what colours can stars be?

Answer 4

blue / red / yellow

Question 5

why is colour used?

Answer 5

to determine the star’s surface temperature

Question 6

a blue star is _____

Answer 6

hotter

Question 7

a red star is _____

Answer 7

cooler

Question 8

a red star is about ____ degrees Celsius

Answer 8

3000

Question 9

a blue star is about _____ degrees Celsius

Answer 9

18000

Question 10

what are the 3 levels of mass?

Answer 10

low, intermediate (medium), high

Question 11

assuming the sun has 1 solar mass, other stars range from ____ solar masses to over ____ solar masses

Answer 11

0.08 / 100

Question 12

what does the evolution of a star depend on?

Answer 12

the mass it had when it originally formed

Question 13

what is a red dwarf?

Answer 13

low mass star

Question 14

what is a red giant?

Answer 14

a dying star that has become large in diameter and cool on the surface

Question 15

what is a white dwarf?

Answer 15

a small, dim and hot star

Question 16

what is a black dwarf?

Answer 16

a white dwarf that runs out of heat and energy

Question 17

what is a neutron star?

Answer 17

a dense star that has only neutrons in its core

Question 18

what is a black hole?

Answer 18

a region where gravitational force is so strong that nothing can escape it

Question 19

what is the life cycle for a low mass star?

Answer 19

around 100 billion years => white dwarf => black dwarf

Question 20

what is the life cycle for an intermediate mass star?

Answer 20

around 10 billion years => red giant => white dwarf => black dwarf

Question 21

what is the life cycle for a high mass star?

Answer 21

around 100 million years => red supergiant => supernova

=> >40 solar mass => black hole
=> < 40 solar masses => neutron star

Question 22

on the H-R diagram, where is luminosity?

Answer 22

the y-axis (vertical)

Question 23

on the H-R diagram, where is temperature and colour?

Answer 23

the x-axis (horizontal)

Question 24

what does the H-R diagram show?

Answer 24

trends in the evolution of stars

Question 25

what is a main sequence star?

Answer 25

the central band of stars stretching from the upper left to the lower right (diagonally)

Question 26

main sequence stars are thought to be what?

Answer 26

at the stable main part of their life cycle

Question 27

the colour of the star relates to the surface temperature because ___?

Answer 27

blue (left) = hotter (left)

red (right) = cooler (right)

Question 28

the cool, bright stars in the H-R diagram are ___ _____ the main sequence

Answer 28

far above