The left arrow allows you to step backward in time. 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. Observing the star Sirius from Detroit, Michigan. Plot altitude on the vertical axis of a graph and azimuth on the horizontal axis. Describe how the azimuth of Sirius changes from star rise to star set.