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Astronomy Lab and Clay Telescope


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Measure Az, El coordinates of Altair and Mizar

to measure Seasonal motion of the stars

SPU-21 Fall 2015

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This lab should serve as an introduction to the night sky. Positions of celestial objects on the sky are measured with two angles: i) azimuth, or the horizontal (in the plane of the ground) angle of the direction to an object vs. the direction to the North, and measured East of North; and ii) elevation, the angle between the object on the sky and the horizon directly below. Celestial positions are changing with time and so three measurements must be made: azimuth, elevation (azimuth and elevation are both in degrees) and time (date and time, to the nearest 30 seconds).

We will measure one star, Altair, in the Summer Triangle and another star, Mizar, in the handle of the Big Dipper on the Science Center roof. The Summer Triangle is a summer asterism and is composed of three very bright stars, Vega (in the constellation Lyra), Deneb (in the constellation Cygnus, the swan) and Altair (in the constellation Aquila, the eagle), so it will be easy to locate.

There will be 2 small Meade telescopes on the roof of the Science Center pointing at the above 2 stars. These telescopes have been aligned to the North Star, Polaris, so the azimuth angle is the number of degrees from True North. Azimuth angles can then range from 0 degrees (North), to 90 degrees (East), to 180 degrees (South), to 270 degrees (West) and then back to 360 degrees (North). Elevation, also referred to as altitude, angles will range from 0 degrees (on the horizon) to 90 degrees (on the zenith).

What you need:



For each star, please pair up your data from the two weeks (one measurement from the first week paired with one from the second week) such that the measurements are done at the same time (closest in hour and minutes). If you were not able to take the measurements at the same time, pair the measurements such that they are as close as possible.

To help with your analysis, please use the spreadsheet that is provided here.

Report your results: