eli5: If the sun revolves around the galaxy, why do we still see the same constellation that was discovered by the Romans (probably 1000s of years ago). surely they should have been scattered by now due to revolution of the sun combined with the revolution of the earth around with sun

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Thnx to all, for the answer. I had a good time discussing and clearing my doubt.

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Each rotation around the sun has a small effect on stats, it is used to measure distance, it is called [https://en.wikipedia.org/wiki/Stellar_parallax](https://en.wikipedia.org/wiki/Stellar_parallax)

The effect is tiny because earth orbit around the sun is small compared to the distance to the start. The closes star Alpha Centauri is 138,000 times the orbital diameter it has a parallax of 750mas. 1 mas =1 Milliarcsecond = 1/3600000=0.00000027 degrees so 750 mas =0.0002 degrees. You need to take images and compare it to stars faster away to see it.

The sun orbits the galactic core but so do the other star. We are around 26,000 lightyears from the galactic center and an orbit take 230 million years. So we have moved less then1/125000 of a revolution in 200 years. One revolution ago was before dinosaurs emerged on earth, earth have obit less than 11 times since it was founded.

Orbital time depend on the distance so object close to the sun will orbit at quite a similar speed. All start you can see with you naked eye are with 4,000 light years.

If you look at the 300 brightest start the median is 185 light year with the distribution below

* <10 light years = 2 stars (Sirius and Rigel)
* 10-100 light years = 79 stars
* 101-1000 light years = 200 stars
* 1000 light years = 19 stars

The result is a consolation change but quite slowly. It is called https://en.wikipedia.org/wiki/Proper_motion and is measured. most start motion is less the 10 mas per year so it is not a lot.

Barnard’s Star moves faster at 10,000 mas per year it is 6 light years from us but it is to dim to see with your naked eye.

61 Cygni A is the faster visible at 5281 mas per year but in 2000 it is still just 3 degrees. It is not a bright start but visible.

The brightest star Sirius moves at 461mas/year is 0.25 degrees in 2000 years

So constellation does change but it is quite slow.

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