Practical exercise 1: WORKING WITH A MOVING STAR MAP OR A PLANETARIUM COMPUTER PROGRAM

Using the program, students watch, looking north, which constellations do not fall below the horizon to a given place. If you are working with a moving star map, then in the upper transparent part there are bounded areas that are below and above the horizon. When rotating this upper part (which changes the day and hour), pupils should find that the part of the stars and constellations that are close to the North Celestial Pole (around the Polar Star) always remains above the horizon (that is, the line on the moving part of the map, which separates the visible part of the sky from its invisible part).

If pupils are working with a computer program, they should choose to "look" north. Then most programs allow you to speed up the natural rotation of the starry sky. It would be good if the program had a landscape/nature depicted and displayed the natural colour of the sky during the day and night. But even if these options are not available, the program should at least include an outline of the horizon. By accelerating the rotation of the sky, students can watch the circumpolar constellations fall to the horizon, but some stars never disappear below the horizon.

No matter what method and program they work with, pupils must calculate and record which constellations in their latitude are "non-decreasing."