2. Lab 6 – The Earth’s Orbital Velocity

4. My radial velocity is 0 mph? V = 80 mph I’m approaching the bus at 20 mph. I’m receding from the ambulance at 20 mph. V = 40 mph V = 60 mph I’m approaching the sports car at 160 mph? V = 80 mph V = 60 mph V = 40 mph

5. V star Arcturus VAVA VBVB ? ? V A = V star + V earth V B = V star - V earth VoVo Arcturus V To Ecliptic V earth = 1/2(V A - V B )/0.86 V star = 1/2(V A + V B ) V earth = 1/2(V A - V B ) V star = 1/2(V A + V B ) - V earth + V earth

6. Earth Distant Star Laboratory - No Radial motion Radial Velocity = 0 Radial Velocity - Radial Velocity + Laboratory Spectrum Blueshift Redshift Spectral Lines Match o 

7. Arcturus VAVA VBVB ? ? o 

8. Red Blue Measure for Plate Scale  -0.15 4260.48 A 4307.91 A -0.37 -25.6

9. r V earth Finding the Radius of the Earth’s Orbit   Circumference of the Earth's Orbit = 2  r ä ä V earth = distance/time time =1 year, ä ä distance = 2  r ä ä V earth = 2  r / time ä ä r = (V earth X time)/2 

10. The End