Chapter 15- Properties of Stars

Question 1

properties of stars

Answer 1

-power source
-density
-age
-size
-temperature
-composition
-distance
-motion
-mass
-luminosity
PDASTCDMML

Question 2

spectroscopy

Answer 2

measuring spectral lines

Question 3

how could we go about proving that stars are like our sun, only farther away

Answer 3

confirm that the luminosity is similar to the suns

Question 4

how do we determine luminosity

Answer 4

• with brightness and distance

- measured in watts

Question 5

solving for brightness

Answer 5

the inverse square law

Question 6

parallax

Answer 6

• apparent movement of foreground object relative to some background due to change in the observers location
• best way to measure distance

Question 7

stellar brightness

Answer 7

lower numbers are brighter and higher numbers dimmer

Question 8

apparent magnitude

Answer 8

based on how bright object appears from earth

Question 9

absolute magnitude

Answer 9

how bright the object would be if it were 10 parsecs away

Question 10

is the suns absolute magnitude higher or lower than its apparent magnitude

Answer 10

higher

Question 11

how can we determine temp

Answer 11

temp determined by where star “peaks” on electromagnetic spectrum

Question 12

spectral classification chart

Answer 12

OBAFGKM

-hottest stars to coolest stars

Question 13

what do absorption lines tell us

Answer 13

ionization and ionization tells us the temp

-therefore absorption lines tells just the temp

Question 14

spectral type

Answer 14

each spectral class is broken down into 10 subclasses

Question 15

size, volume, mass differences

Answer 15

size= how big(radius)
volume= how much space
Mass=How much stuff

Question 16

stellar mass

Answer 16

use keplers third law is how you find the stellar mass, but you have to have 2 or more Stellar binaries

Question 17

spectroscopic binary

Answer 17

• astronomers can’t see both stars

- detected through Doppler Shifts in spectral lines

Question 18

eclipsing binary

Answer 18

• one star periodically blocks the light of other star

- can give astronomers both mass and size

Question 19

what does being in the main sequence mean

Answer 19

when stars are undergoing thermonuclear fusion of hydrogen and helium in their core

Question 20

visual binary

Answer 20

when astronomers can see both stars

Question 21

luminosity class

Answer 21

tells you about luminosity and size

Question 22

how much mass a star has relates to what

Answer 22

• the stars life expectancy
• low mass=long lifetime
• high mass=short lifetime

Question 23

what does star clusters tell about stars

Answer 23

• all stars are around the same age

- star formation makes many more low mass stars then high mass stars

Question 24

open cluster

Answer 24

a few thousand loosely park stars

Question 25

globular cluster

Answer 25

up to a million or more stars in a dense ball bound together by gravity