Kit "Stardial" AstroMedia

Kit AstroMedia for building the "Stardial".

Cardboard kit for a star clock that can be used to tell the time by looking at the night sky.

Not groping in the dark

How did people in former times tell the time at night? This reconstruction of the star clock invented about 500 years ago makes use of the fact that the constellation Big Dipper orbits Polaris once in 23 hours and 56 minutes, as if it were the needle on a giant clock. Because of the difference of 4 minutes compared to a whole day, the sidereal clock is set to the current date before reading, then it shows the True Local Time with amazing accuracy. You can even feel it with your fingertips in the dark.
On the back of the sundial is a sailor's astrolabe for determining the altitude of the sun, stars and Landmarks.

How it works

Turn the date disc until the current date is in the read-out window of the handle above the arrow mark. Find the constellation Big Dipper and from there the North Star. Hold the star clock by the handle so that it points vertically downwards and, with your arm half bent, take a bearing on Polaris through the hole in the axle. Turn the star pointer until its straight edge is parallel to the two rear stars of the Dipper. The Big Dipper on the star clock is now positioned like the one in the sky. Read the True Local Time in the read-out window of the star pointer or feel the time using the long and short spikes of the hour disc.

Dettagli prodotto:

• sturdy kit made of die-cut cardboard and with noble gold print
• size of the built article:
•  total: 21 x 23 cm (Ø of the disc: 16 cm, plus 5-7 cm handle)
• The construction time is about 4 hours.