Ch. 19

Question 1

Parallax

Answer 1

Apparent movement of a body depending on the movement of the observer

Question 2

Angles

Answer 2

1 angle of arc = star 1 parsec from Earth

Question 3

Radar Telescope

Answer 3

Sends and receives radar waves to measure distances to planets, satellites, and asteroids

Question 4

Triangulation

Answer 4

Viewing from different vantage points

Question 5

Stellar Distance

Answer 5

D = 1 / p

Question 6

Bessel

Answer 6

Made first successful detections of stellar parallax

Question 7

Cepheid Method

Answer 7

(1) Find star and measure period
(2) Use period-luminosity to calc luminosity
(3) Measure apparent brightness
(d) Compare distance

Question 8

Henrietta Swan Leavitt

Answer 8

Discovered relation between period and luminosity

Question 9

Large Magellanic Cloud

Answer 9

Neighboring galaxy, provided good opportunity to study behavior of variable stars

Question 10

Order of distance measurements

Answer 10

AU < light year (9.5 * 7^12km) < parsec

Question 11

H-R Diagram of Stars Measured by Gaia and Hipparcos

Answer 11

(upper right) old age (lower left) white dwarfs (lower right) red dwarfs

Question 12

Light Curve

Answer 12

(max) greatest brightness (min) faintest (btwn two maxima) period

Question 13

Pulsating Variable Star

Answer 13

Changes its diameter with time – expanding + contracting

Question 14

Cepheid Variables

Answer 14

Large, yellow, pulsating stars (i.e. Polaris) // quick max light rise and fall

Question 15

Period-Luminosity Relation

Answer 15

Distance = energy of star - apparent brightness

Question 16

John Goodricke

Answer 16

Discoverer of Delta Cephei // observed Algol: bright variable star

Question 17

John Goodricke

Answer 17

Discoverer of Delta Cephei // observed Algol: bright variable star

Question 18

Luminosity Classes

Answer 18

(1a) Brightest Supergiants
(1b) Less luminous supergiants
(2) Bright giants
(3) Giants
(4) Sub-giants
(5) Main-sequence stars