Lab 6 – The Earth’s Orbital Velocity
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
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
Earth Distant Star Laboratory - No Radial motion Radial Velocity = 0 Radial Velocity - Radial Velocity + Laboratory Spectrum Blueshift Redshift Spectral Lines Match o
Arcturus VAVA VBVB ? ? o
Red Blue Measure for Plate Scale A A
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
The End