Why do modern astronomers contains continue to use the celestial sphere whem they know that stars are not all?

Answer 1

For observing stars, they may as well be affixed to a celestial sphere. The stars move across the sky as the Earth rotates, but they do not change position relative to one another. Therefore, the celestial sphere coordinates are a very convenient way to describe locations in the sky.

Answer 2

The celestial sphere shows what the sky looks like, and it shows where to look to see an object. For most astronomical objects, we know the position on the celestial sphere very accurately, but we don't know the distance very well.

It would be lovely to make a 3-dimensional representation of space in your living room or classroom, but how would you do it?

Answer 3

They continue to use the celestial sphere because they know and understand that the fartherest visable dimension outward in space is 46 Billion Light Years in every direction from Earth. That is not the end of space, that is only what we have been able to see with the aid of the Hubble Space Telescope and various radio telescopes on mountain tops here on Earth. So a sphere continues to be the ideal choice to map what we know and what we have found out from study of the vast universe.