Triangulation Prac
𝑜
𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑜𝑓 𝑆𝑢𝑛 𝑡𝑜 𝑠𝑡𝑎𝑟
𝑎
𝐷𝑖𝑠𝑡𝑎𝑐𝑒 𝑓𝑟𝑜𝑚 𝑆𝑢𝑛 𝑡𝑜 𝑃𝑙𝑎𝑛𝑒𝑡
Tan(ϴ)= =
Distance of Sun to star = tan(ϴ) x Distance from Sun to Planet
Planet A
Distance from Sun to Planet =____________m
Angle Measured
Distance of Sun to
each star (m)
Class Average (m)
Percent Error
Star 1
Star 2
Star 3
Star 4
Planet B
Distance from Sun to Planet =____________m
Angle Measured
Distance of Sun to
each star (m)
Class Average (m)
Percent Error
Class Average (m)
Percent Error
Class Average (m)
Percent Error
Star 1
Star 2
Star 3
Star 4
Planet 3 Distance from Sun to Planet =______________m
Angle Measured
Distance of Sun to
each star (m)
Star 1
Star 2
Star 3
Star 4
Planet 4 Distance from Sun to Planet =______________m
Angle Measured
Distance of Sun to
each star (m)
Star 1
Star 2
Star 3
Star 4
After we have a class average I will provide you with the actual distance to each Star. To
calculate the percentage errors, take the difference between actual distance and the average
above, then divide that by the actual distances and multiply it by 100.
Percent Error =
𝐴𝑐𝑡𝑢𝑎𝑙 𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 − 𝑇ℎ𝑒 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝐴𝑐𝑡𝑢𝑎𝑙 𝐷𝑖𝑠𝑛𝑡𝑎𝑛𝑐𝑒
× 100
Questions:
1. What patterns do you see?
a. On average which stars were more accurate to measure
distances for, close stars or far away?
b. On average which planets were more accurate to measure
distances for, closer to the sun or further away?
2. If we used the parallax angle instead of the alpha angle as we’ve
done above to calculate distance, what would the formula look like?
3. For an actual star with a parallax angle of .1944 arcseconds, what is
its distance from us in kilometers? Use 149,598,000km as the
distance from the Earth to the sun. Remember that one arcsecond is
1/3600 of a degree.