1. Lab 12 Altitude and Azimuth
Objectives:
To learn about the horizon coordinate systems…
…its strengths and weaknesses
Observe the daily motion of the sky.

2. Horizon coordinate system Altitude
Lab 12
Horizon coordinate system
Altitude
How High in the sky should I look?
…on the horizon, overhead (zenith), halfway up?
Azimuth
In what direction should I look?
…North, South, East or West?

3. Where is Polaris? Face North
Lab 12
Where is Polaris?
Face North
Its height above horizon always equals your latitude
40° for Sacramento area
Approximately ½ way above the horizon

4. Transfer from Lab 10 (or re-measure)
First set of observations….
Transfer from Lab 10 (or re-measure)
Lab 1B page 3 transparency CHART
Step 2 - Discuss Alt/Az measurement tasks – Table B

5. East
West
How to find the 6 stars
South

6. East
West
How to find the 6 stars
South

7. West
East
Finding North - Polaris
North

8. West
East
Finding North - Polaris
North

9. Second set of observations (two phases of them)
Find some place where Betelgeuse is sitting on top of some solid, immobile object—a flagpole, corner of a building, etc.
And…where you’ll still be able to see it as Betelgeuse drifts towards the west…. (to the right, as you face south)
Mark the ground.
Note the time to the nearest minute.
Lab 1B page 3 transparency CHART
Step 2 - Discuss Alt/Az measurement tasks – Table B

10. Second set of observations (two phases of them)
Return 90 minutes (or more) later.
Stand on the exact same spot, with the exact same posture. Measure the distance the star has moved from its starting point.
Note the time to the nearest minute.
Lab 1B page 3 transparency CHART
Step 2 - Discuss Alt/Az measurement tasks – Table B