I get to write with the intention of trying to explain how affects the direction of an observatory in the contemplation of heaven to the naked eye or with optical instruments such as binoculars or telescopes.

To do this, we must first consider what is the behavior of the apparent motion of the heavenly bodies and how they evolve and end their journey. We know that the Sun, the most prominent object in the sky, rises from the east, gets higher in the sky up to its maximum in the North, which also receives the name of midday, and then begins to descend, until it dies in the western horizon.

We also know that this movement of the sun is not so, but actually an optical illusioncaused by the Earth’s rotation around its own axis, completing one full revolution every 24 hours, period which we have agreed to call “day.”

But the Sun is not the only one who suffers the effects of Earth’s rotation, but ALL of theheavenly bodies, except for the circumpolar constellations, revolving around the South Celestial Pole, and due to their proximity to it, never disappear below the horizon.

All the other stars “come out” from the east, reach their highest altitude in the North and”die” or put in the west. This includes the moon and all planets of the Solar System.

The immediate consequence of this is that the stars are most clearly seen in the North, which is where they reach their maximum altitude above the horizon, and therefore avoid air pollution and obstacles in our line of sight, away from the possible sources of light pollution by mercury and sodium vapor streetlights of the public and other light sources in the neighborhood.

There is a but to this general rule: there are many stars that reach their maximum altitudes upon us, which really becomes uncomfortable, it is not easy to observe for a held while the stars that lie just above our heads . With certain types of telescopes (known as refractors), observation is really cumbersome.

That’s why so many amateurs, myself included, prefer watching halfway between the rising of the star in question (the East) and their transit or culmination (the North), a fact that occurs in about the Northeast, making this point, therefore, ideal for the study and enjoyment of the wonders of our sky.