Paul Floyd's Astronomy & Space Website: Make a Southern Cross finder

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Make a Southern Cross finder

Want to find the Southern Cross at night? Make a Southern Cross finder which has been designed to be used from anywhere in South East Queensland using nothing more than a few pieces of paper, glue and a split pin.

Materials

The only materials you will need to construct the finder are:

The Southern Cross finder base (Acrobat.pdf file)
The Southern Cross star disc (Acrobat.pdf file)
One split pin (or a paper clip)
Cutting implement
Optional (but recommended) - You may wish to attach the base and star circle to a piece of thin cardboard so that the completed finder is more durable.

Instructions

On the base, cut along the thin curved horizontal line - so that you have made a slit. This is where you will insert the star disc.
Cut out the star disc.
Make a small hole in both the star disc and the base where the small crosses are marked.
Attach the star disc to the base using the split pin ( or a paper clip) so that it spins freely.
Once the star disc is attached, insert the part of the star disc that is below your horizon into the slit you have made. This means that the finder will hide the stars that are below your local horizon (just like the real sky).
Turn the wheel until the time and date match the current date and time.
Turn to face South and hold the finder up in front of you. Use the finder to locate the Southern Cross and the Pointer Stars (or Alpha and Beta Centauri).

Additional usage comments

The Southern Cross finder has a number of other uses.

You can use the Southern Cross finder as a clock. To do this simply turn the star disc so that the position of the Southern Cross on the disc matches the orientation of the real Southern Cross. Then find the today's date on the disc and see what time it is next to. That is the current time.
You can also use the finder to help you locate South. The point in the Southern sky that the stars appear to rotate around (spin the disc quickly and you will see what I mean) is known as the South Celestial Pole. Locate that point in the sky and then move your eyes directly to the horizon. The direction you are looking is South.
At certain times of the year, you can use the finder to help you locate the Small and Large Magellanic Clouds. These are satellite galaxies of our Milky Way galaxy that are so close to our galaxy that they can be easily seen with the unaided eye from a dark sky location.