DVC Astronomy 110 - Exam #2
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What is the azimuth (A) ? - Answer The angle measured beginning at cardinal point
North moving eastward along the horizon to the base of the Vertical Circle of the object.
*The azimuth is measured in units of degrees
What is the altitude (h) ? - Answer The angle measured upward from the horizon along
the vertical circle of an object to the object itself.
*The altitude is measured in degrees
What is the meridian altitude? - Answer The altitude of the object when it passes through
upper transit. This is the maximum altitude an object can achieve on ANY given night.
What is the vertical circle? - Answer A line from the zenith through the object that meets
the horizon to form a right angle.
What are circumpolar objects? - Answer Objects that are ALWAYS above the horizon.
Describe the motion of the stars when looking to the north. - Answer The stars appear to
rotate COUNTER-CLOCKWISE with Polaris near the center of the makeshift vortex.
What is the formula for determining rising azimuth or setting azimuth? - Answer RISING
AZIMUTH + SETTING AZIMUTH = 360 degrees
Describe the motion of the stars when looking South. - Answer The stars move
clockwise and run parallel to the equatorial meridian.
Do stars trace the same path every day? - Answer Yes, stars trace the same path every
day.
Define: Latitude and Longitude - Answer Latitude: the angle measured north or south of
the Earth's equator.
Longitude: the angle measured east or west of the Prime Meridian.
What is the longitude and latitude of DVC? - Answer Latitude: 38 degrees N
Longitude: 122 degrees W
the synonym of Diurnal - Answer the synonym of Daily
If a constellation rises at Azimuth 130, what is its setting azimuth? - Answer The setting
Azimuth is 230 degrees.
, Do all star paths run parallel? - Answer Yes, all star paths run parallel. All stellar diurnal
paths are parallel to one another.
Where will a star set tomorrow as opposed to today? - Answer A star will set in the exact
same place, it will also transit and rise in the same place. However, tomorrow it will rise,
transit and set 4 minutes earlier than today.
Does the Earth rotate East to West? - Answer No, the Earth rotates West to East, which
makes the celestial sphere appear to move East to West.
What is always equal to the observer's latitude? - Answer The North Celestial Pole.
What is the Meridian Altitude of the Celestial Equator equal to? - Answer The Meridian
Altitude of the Celestial Equator is equal to the observer's CO-LATITUDE.
What is the Meridian Altitude for a star rising at Cardinal Point East @ DVC? - Answer
The Meridian Altitude of a Star Rising at Cardinal Point East is 52 degrees at DVC.
What is the North Celestial Pole (NCP)? - Answer The projection of the Earth's North
Pole on the celestial sphere.
What is the formula for finding the Co-Latitude? - Answer 90 degrees - observer's
latitude = Co - Latitude (which is equal to the Celestial Equator's Meridian Altitude)
What is the celestial equator? - Answer A great circle on the celestial sphere that is 90
degrees away from the celestial poles. The Celestial Sphere also runs parallel to the
stellar diurnal paths.
What is circumpolar at the Earth's equator? - Answer Nothing is circumpolar at the
Earth's equator.
What is stellar diurnal motion? - Answer The apparent stellar motion detected WITHIN a
day and usually described with an hourly rate of about 15 degrees per hour.
The stars APPEAR to move 361 degrees in a 24 hour period at a rate of about 15
degrees per hour, east to west with respect to the horizon along the diurnal path.
Reason: Earth rotates 15 degrees per hour WEST TO EAST.
Describe the DAILY motion of the star sphere. - Answer 361 degrees/day E -> W with
respect to the horizon
At what rate (per hour) does the star sphere move? - Answer ~ 15 degrees/hour E -> W
with respect to the horizon
What star straddles the Celestial Equator? - Answer MIntaka.
In one day, how far will a star appear to have moved? - Answer Approximately a 1
degree shift to the West (with respect to the horizon). The actual shift is .99632 degrees
What is stellar ANNUAL motion? - Answer The net motion detected after an exact 24
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What is the azimuth (A) ? - Answer The angle measured beginning at cardinal point
North moving eastward along the horizon to the base of the Vertical Circle of the object.
*The azimuth is measured in units of degrees
What is the altitude (h) ? - Answer The angle measured upward from the horizon along
the vertical circle of an object to the object itself.
*The altitude is measured in degrees
What is the meridian altitude? - Answer The altitude of the object when it passes through
upper transit. This is the maximum altitude an object can achieve on ANY given night.
What is the vertical circle? - Answer A line from the zenith through the object that meets
the horizon to form a right angle.
What are circumpolar objects? - Answer Objects that are ALWAYS above the horizon.
Describe the motion of the stars when looking to the north. - Answer The stars appear to
rotate COUNTER-CLOCKWISE with Polaris near the center of the makeshift vortex.
What is the formula for determining rising azimuth or setting azimuth? - Answer RISING
AZIMUTH + SETTING AZIMUTH = 360 degrees
Describe the motion of the stars when looking South. - Answer The stars move
clockwise and run parallel to the equatorial meridian.
Do stars trace the same path every day? - Answer Yes, stars trace the same path every
day.
Define: Latitude and Longitude - Answer Latitude: the angle measured north or south of
the Earth's equator.
Longitude: the angle measured east or west of the Prime Meridian.
What is the longitude and latitude of DVC? - Answer Latitude: 38 degrees N
Longitude: 122 degrees W
the synonym of Diurnal - Answer the synonym of Daily
If a constellation rises at Azimuth 130, what is its setting azimuth? - Answer The setting
Azimuth is 230 degrees.
, Do all star paths run parallel? - Answer Yes, all star paths run parallel. All stellar diurnal
paths are parallel to one another.
Where will a star set tomorrow as opposed to today? - Answer A star will set in the exact
same place, it will also transit and rise in the same place. However, tomorrow it will rise,
transit and set 4 minutes earlier than today.
Does the Earth rotate East to West? - Answer No, the Earth rotates West to East, which
makes the celestial sphere appear to move East to West.
What is always equal to the observer's latitude? - Answer The North Celestial Pole.
What is the Meridian Altitude of the Celestial Equator equal to? - Answer The Meridian
Altitude of the Celestial Equator is equal to the observer's CO-LATITUDE.
What is the Meridian Altitude for a star rising at Cardinal Point East @ DVC? - Answer
The Meridian Altitude of a Star Rising at Cardinal Point East is 52 degrees at DVC.
What is the North Celestial Pole (NCP)? - Answer The projection of the Earth's North
Pole on the celestial sphere.
What is the formula for finding the Co-Latitude? - Answer 90 degrees - observer's
latitude = Co - Latitude (which is equal to the Celestial Equator's Meridian Altitude)
What is the celestial equator? - Answer A great circle on the celestial sphere that is 90
degrees away from the celestial poles. The Celestial Sphere also runs parallel to the
stellar diurnal paths.
What is circumpolar at the Earth's equator? - Answer Nothing is circumpolar at the
Earth's equator.
What is stellar diurnal motion? - Answer The apparent stellar motion detected WITHIN a
day and usually described with an hourly rate of about 15 degrees per hour.
The stars APPEAR to move 361 degrees in a 24 hour period at a rate of about 15
degrees per hour, east to west with respect to the horizon along the diurnal path.
Reason: Earth rotates 15 degrees per hour WEST TO EAST.
Describe the DAILY motion of the star sphere. - Answer 361 degrees/day E -> W with
respect to the horizon
At what rate (per hour) does the star sphere move? - Answer ~ 15 degrees/hour E -> W
with respect to the horizon
What star straddles the Celestial Equator? - Answer MIntaka.
In one day, how far will a star appear to have moved? - Answer Approximately a 1
degree shift to the West (with respect to the horizon). The actual shift is .99632 degrees
What is stellar ANNUAL motion? - Answer The net motion detected after an exact 24
