Twinkling of Stars | Motion of the Sky | Seasonal Changes in The Constellations

1. Twinkling of the Stars 50 points

Twinkle, twinkle, little star... Stars twinkle because we have to look up through the Earth's atmosphere in order to see them. As the light from the star comes through the atmosphere it gets refracted so that the star's apparent position and its color change rapidly. Since stars are so far away they only appear as points of light - even through a telescope - this single point of light is easy to distort. Stars closer to the horizon twinkle more. That is because when we look toward the horizon we must look through more air than when we look directly above us.

If you see a bright star near the horizon verify with your naked eyes that it is twinkling more than a star near the top of the sky. Compare the star's appearance as viewed by naked eye and telescope. Guiding Questions: Does the image of the star stay in the same position? What color is the star? How quickly is the brightness of the star changing? Which way are you looking? Over the city or away from the city? Is the wind blowing?