Project Goal: To observe the changing altitude and azimuth of the star sirius from star rise to star set.
What You Need for This Project
To do this project you will have to be able to view the movie clip included with this project. All Macs come with a version of QuickTime and computers running Windows have a movie viewer called Media Player. The movie clip should play using either type of computer or player.
If your computer does not have QuickTime movie viewer installed you can download the Macintosh or Windows version from the internet by clicking on QuickTime. Also, an installable version of QuickTime is included on the StarryNight CD program disk.
Start the movie and watch as Sirius rises and sets. Drag the horizontal scroll box to the left to rewind to the first frame of the movie. Clicking once to the right of the scroll box will advance to the next time frame. Alternately, if you are using a QuickTime viewer, you can click the right arrow at the end of the scroll bar. Each click advances one time frame forward. The left arrow allows you to step backward in time.
What You Need to Know for This Project
In the upper left hand corner of the movie screen you will see the date and time, as well as the altitude, and azimuth of Sirius. This data updates as you change frames.
Record the time and corresponding altitude, and azimuth of Sirius begining at star rise and ending at star set. Make sure that you determine the time, altitude, and azimuth of upper transit. Upper transit is when the altitude of an object is largest. For a discussion of astronomical coordinate systems see Voyage 4 .
To begin your observations click The Diurnal Motion of Sirius
Print or copy the Project Results Form on which to record you answers and hand it in to your instructor.
Results Form
Name____________________ Student Number__________ Class ______________
Date ____________________
Task 1: Observing the star Sirius from Detroit, Michigan.
Dates of Observation ______________
Time Altitude Azimuth
Rising____________(AM, PM)______________________________
_________________(AM, PM)______________________________
_________________(AM, PM)______________________________
_________________(AM, PM)______________________________
Transit___________(AM, PM)______________________________
_________________(AM, PM)______________________________
_________________(AM, PM)______________________________
_________________(AM, PM)______________________________
Setting___________(AM, PM)_______________________________
Task 2: Plot altitude on the vertical axis of a graph and azimuth on the horizontal axis.
Based on your observations:
1. Describe how the altitude of Sirius changes from star rise to star set.
2. Describe how the azimuth of Sirius changes from star rise to star set.
3. What causes the altitudes and azimuths of celestial objects like Sirius change over time?
4. Did the Right Ascension (RA) andDeclination (DEC) of Sirius change with time?