Some constellations such as Ursa Minor, are visible in the sky year round other constellations appear for only part of the year.Explain why this happens.

http://curious.astro.cornell.edu/question.php?number=300

Note that if you are in the Northern hemisphere You can see stars that are high in the northern sky all year. It is the ones close to the plane of the earth's orbit that you can only see when you are facing them at night.

The visibility of constellations in the sky depends on the Earth's movement around the Sun and its tilt on its axis. The Earth takes approximately 365 days to complete one orbit around the Sun, which creates the cycle of the seasons. The Earth's axis is tilted at an angle of about 23.5 degrees relative to its orbit.

As the Earth orbits the Sun, different parts of the sky become visible during different times of the year. This is because the Earth's tilt causes different regions of the sky to be exposed to sunlight at different angles throughout the year.

For constellations that are visible year-round, such as Ursa Minor (the Little Dipper), they are located toward the North Pole of the Earth's axis. This means that they are always above the horizon and are visible no matter the season.

On the other hand, constellations that appear for only part of the year are located towards the celestial equator or further towards the South Pole of the Earth's axis. During certain times of the year, these constellations align with the Earth's orbital plane around the Sun, making them visible at night. However, as the Earth continues to orbit, different constellations come into view while others move out of sight.

So, the visibility of constellations in the sky throughout the year is a result of the Earth's orbital motion, its axial tilt, and the position of the constellations relative to our planet.