Astronomy 1020
Study Guide – Chapter 2
Chapter 2
page Column Keywords
27 right constellation
official borders of constellations set by IAU
88 constellations
28 left constellations visible from southern hemisphere named
by seventeenth-century European explorers
celestial sphere
right north celestial pole
south celestial pole
celestial equator
ecliptic
whitish band of light – Milky Way Galaxy
29 left traces galactic plane as viewed from our location
shape of Milky Way Galaxy
right we see half the celestial sphere at any one time
local sky
horizon
many ancient peoples – flat Earth
zenith
meridian
direction and altitude
30 angular size
angular distance
rough estimates of angular size using hand
right arcminutes
arcseconds
1 = 60 arcminutes = 3600 arcseconds
angular unit abbreviations
The Circling Sky
stars rising and setting really Earth moving
31 left paths of stars – orange dots
33 left latitude, longitude, prime meridian
right locations with same latitude see the same constellations
34 left at north pole only circumpolar stars can be seen
Sun visible for 6 months out of the year
northern hemisphere – altitude of Polaris is your latitude
35 left Seasonal Changes in the Night Sky
constellations visible depend on time of year
Earth orbits Sun in counter-clockwise direction
ecliptic
zodiac
Sun’s apparent location among the zodiac constellations
36 tilt of Earth’s axis causes seasons
37 left seasons only caused by axis tilt, not by variation of
distance from Sun
right solstices and equinoxes – stuff with orange dots
