Why is the ecliptic different from the celestial sphere if they are both perceived?
The ecliptic and the celestial sphere are different things. The celestial sphere is the imaginary sphere on the sky, with stars fixed to it that rotates once per day- it’s a two-dimensional projection of the sky onto a spherical shell around the Earth. The ecliptic is the path the Sun takes around the sky, once per year, with respect to the celestial sphere. See above few questions also. I was a little confused by the circumpolar definition since you only see stars at night (i.e. part of daily rotation). Does that mean that you can only see some stars during certain seasons or at certain points in a night? (for instance, for one of the stars that makes a loop below the horizon, when is it not visible? During a certain season or a certain part of the day?) Yes, some stars can be seen only in certain times of year and only at certain times during a particular night. You can see given star when two conditions are satisfied (assuming no clouds, trees or buildings are in the way!): first, t
