Summer/Winter and Precession.

[interstellar]

Right now Polaris is our north polar star. In 12,000 years Alpha lyrae will be, correct? How will this effect the summer in the northern hemisphere. Will are days be even longer than they are now and the Suns cross the meridan higher in the sky? A interesting speculation. And will contellations like Sagittarius ride higher in our night sky?

[renormalised]

Won't make any difference to the northern summer, unless the obliquity of the axis changes. Then it will. However, the Sun will rise in another part of the sky relative to the Zodiac than it does now. In all likelyhood, the obliquity will change so there will be some effect on the seasons across the planet. What that change will be is uncertain...just depends on how the angle of the axis of rotation (obliquity) changes. However a change in the obliquity will cause the Sun to ride higher or lower in the sky, depending on the change. Same with the constellations.