NATS 1740 Lecture Notes - Lecture 5: Sidereal Time, Electric Light

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Michael De Robertis, Alireza Rafiee

Document Summary

Star trails (time exposure) shows the south celestial poles (scp) and the celestial equator. You can calculate how far away are those trails. + the sun rises in a specific direction as earth orbits the sun. We are ruled by the sun, solar day = 24 hours (when earth comes back at the same point) Stars don"t come back at the same point after 24 hrs, they come back 23 hrs, 56 mins later. => sidereal day (measured by time of a particular star go once around the sky) (earth"s roation period) = 23 hours 56 minutes. + why sidereal day 4 minutes shorter? the sun => 24 hours, earth orbits the sun in the same direction as it rotates its axis. Solar day, the sun is on the right in the middle of the sky and the earth points at. Sidereal day, the earth"s point to the same star. Stars rise and set because of earth"s rotation.