Ch 2 Key Terms

Question 1

Apparent magnitude

Answer 1

Measure of how bright a star looks in the sky: larger the #, dimmer it appears

Question 2

Astrology

Answer 2

Pseudoscience that deals w the supposed influences on human destiny of the configurations and locations in the sky of sun moon and planets

Question 3

Celestial equator

Answer 3

Big circle on clelestial sphere that is 90 degrees from poles (equator)

Question 4

Celestial poles

Answer 4

Points on which the celestial sphere appears to rotate on

Question 5

Celestial sphere

Answer 5

The sphere we see when we look at the sky

Question 6

Circumpolar zone

Answer 6

Portions of celestial sphere that are always above or below horizon

Question 7

Cosmology

Answer 7

Study of the organization and evolution of universe

Question 8

Ecliptic

Answer 8

Suns path on celestial sphere

Question 9

Epicycle

Answer 9

Circular orbit a body takes in Ptolemys system, center of body goes around deferent

Question 10

Geocentric

Answer 10

Centered on earth

Question 11

Heliocentric

Answer 11

Sun centered

Question 12

Horizon

Answer 12

90 deg from zenith, where dome meets earth

Question 13

Horoscope

Answer 13

Chart used to show positions along zodiac (w sky, sun, planets)

Question 14

Parallax

Answer 14

Apparent displacement of a nearby star caused by motion of earth around sun

Question 15

Planet

Answer 15

Large objects revolving round sun

Ancient times: object that moved among fixed stars

Question 16

Precession

Answer 16

(Of Earth)

Slow motion of earths axis of rotation caused by gravitational pull of moon and sun

Question 17

Retrograde motion

Answer 17

Westward motion of a planet on celestial sphere

Question 18

Year

Answer 18

Period of revolution of earth around the sun

Question 19

Zenith

Answer 19

Directly above observer

Question 20

Zodiac

Answer 20

Belt around sky about 18 deg wide on the ecliptic