Project Description

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Project: Length of a Sidereal Day

Tier: 2

Location: home

Other information, requirements, or equipment you must supply (may be blank):

Find a location where you can observe a star in exactly the same position on several nights, for example, aligned with an antenna or cell phone tower. The southern sky is best.

Draw a sketch of the star and the thing(s) it aligns with, and write a short paragraph on how you will know when it is in exactly the right place, including the name of the star you are using.

Create a table with two columns, date and time.

Record the date of your first observation, and the time to the nearest second when the star is in position in the first row.

5 days to 2 weeks latter, fill in the next row of the table with the date and time to the nearest second when the star aligns in the same place.

Repeat the observation one more time, 5 days to 2 weeks from the second observation, so your table has 3 rows of data.

Use the data in the table to calculate the length of the sidereal day. Show your work. Write a paragraph on how accurate your calculation is compared to the accepted value and where you think the biggest errors could have come from.