Any sky object within (your latitude) degrees of the north celestial pole.
The answer depends on where you are. For a places further north than 73½º north Aldebaran never sets at all. Alternatively for places further south of 73½º south it never rises. In between, it depends on the latitude.
latitude and longitude
latitude and longitude
Longitude and latitude.
Sets of numbers that show where lines of latitude and longitude meet are called coordinates. Coordinates are used to specify exact locations on the Earth's surface.
Where the Sun Never Sets was created on 2005-08-15.
A Sun That Never Sets was created on 2001-08-07.
Stars near the north celestial pole and the south celestial pole become "circumpolar" at high latitudes. They "circle around the pole". For example, the star Polaris never sets anywhere in the northern hemisphere. Constellations like the Big Dipper, Draco or Cassiopeia are "circumpolar" north of about 30 degrees north latitude. While there is no "south pole star", a constellation such as the Southern Cross is circumpolar south of about 40 degrees South.
Geographic or map coordinates.
they are parallel
The answer depends on where you are. Arcturus has a declination of 19¼ degrees north, which means it passes overhead at all places with a latitude of 19¼ degrees north. For a places further north than 70¾º north Arcturus never sets at all. Alternatively for places south of 70¾º south it never rises. In between, it depends on the latitude.
never