Star Vocabulary
This is the point directly above the observer.
Zenith
This is the name given to the position of a planet (or moon) when it is observed directly opposite the sun from the Earth. Objects in this position rise at sunset and set at sunrise.
Opposition
This star is at a constant altitude of 47.5 degrees.
Polars
The sun culminates each day as it crosses this line.
The meridian
This phase rises and sets with the sun
Full Moon
This is the degree of brightness of the star.
Magnitude
This is the periodic apparent westward motion of the planets against the fixed stars.
Retrograde Motion
These three stars appeared on our circumpolar star chart and have a magnitude 0 or 1.
Cappella, Vega and Deneb
Each day the sun drifts eastward against the background of the fixed stars, giving the appearance that the stars set ____ minutes before the sun each day.
four
The moon in this phase rises around sunset and sets around sun rise.
Full Moon
This is the distance of a star from the celestial equator. It is measured in degrees and does not change.
Declination
This is the distance of a star (in degrees) above the horizon; observing the sun from Spokane at solar noon, this value varies from 19 degrees to 66 degrees throughout the year.
Altitude
This group of constellations never set, staying above the horizon 24 hours a day, 365.2422 days a year.
Circumpolar
This is the name for the path the sun traces through the fixed stars each year.
Ecliptic
During these two phases 2/8 of the moon is illuminated.
First and Last (or third) quarter
This is when a star reaches its highest altitude and occurs as the star crosses the meridian of the observer.
culmination
This is measured as the average time span from one solar noon to the next.
A solar day
Stars with this type of declination are above the horizon less than 12 hours in a 24 hour day.
Southern
The sun travels along this line of declination from sunrise to sunset on both equinoxes.
0 or the celestial equator
This phase rises a few hours before sunset (approximately 3pm) and will set before sunrise (approximately 3am)
waxing gibbous
This is the apparent turning of the stars around the fixed pole star.
Diurnal Motion
This is when the sun crosses the meridian and is at its highest point in the sky for the day.
Solar Noon
As observed from Spokane, a star that is on the celestial equator will rise in the east at an angle of _______ to the horizon.
42.5 degrees
It takes ________ days for the moon to orbit the earth and catch up with the sun thus restarting its phases.
~29
The points (or horns) of this phase point west.
Waning Cresent