Trivia 6

We can only see above the horizon, day or night. During the night sky observation, we see the stars above our horizon. Let us define some terms, for those of you who want to get oriented in the sky, and are doing it for the first time.

With the help of a compass, you can locate the North-South direction. You then can face North or South. Now look up, directly above you, that is the zenith of the celestial sphere. Yes, we feel like a chicken under a wire concave lid, and the zenith is the ring to lift it. If you trace with your extended arm an imaginary line above your head from North to South, you are tracing your Meridian. You will see the celestial sphere “moving” with all the stars from East to West. The stars are so far away that we do not perceive their motions (they are moving!), but we see them in a relative motion with respect to the Earth, as it moves from West to East in its daily rotation. We perceive the sky moving from East to West. The celestial objects are going to transit form East to West your celestial meridian. When the stars are exactly on your meridian, we say they that the star culminates; that indicates that the object has reached is maximum altitude.

Published by pkrumbein

Retired Physics/Astronomy teacher and instructor. Master in Physics Education and Master in Astronomy and Astrophysics. My interests are in reading and writing.

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