# Need help with Star Polaris (altitude and Azimuth)

1. Sep 6, 2008

### Confused_Star

1. The problem statement, all variables and given/known data

The star that I am looking for is Polaris. I Need to know the azimuth and altitude of the star polaris for a 2 hour period checking it ever fifteen minutes. I am in Middle Tennesse. Tonight (09/6/08) I come up with an azimuth of 20 degrees and the altitude was 77-78 Degrees. Can someone tell me if this sounds right. Also what is the reason the star did not change? And if I was to look at the same star tomorrow night at the same time would its position be different or the same and why?......and the same goes for if a month from now would it be the same or different and why?......this would really help me....I will take anything i can get!

Confused_Star

2. Relevant equations

3. The attempt at a solution

2. Sep 7, 2008

### Staff: Mentor

Have you ever seen long exposure picture of a night sky, with stars making circles? Like here:

That's because the Earth is revolving. Why circles are larger and smaller? Polaris is close to the center of the picture.

Last edited by a moderator: May 3, 2017
3. Sep 7, 2008

### HallsofIvy

Staff Emeritus
The stars appear to move in circles because, of course, the earth turns! As the earth turns the stars appear to rotate in circles whose center is the line through the earth's axis. Polaris happens to be very close to that line. It is not exactly on that line but it is very close to it. Thus, while it does move, it moves in very small circles. Its position does not change much.

4. Sep 7, 2008

### Staff: Mentor

I hoped OP will find it out by himself...

5. Sep 8, 2008

### chemisttree

Polaris will be straight up at zenith if you were at the north pole (90o altitude) and at 0o altitude at the eqator. How far up will it be at your latitude? (check a map)

Another name for Polaris is the North Star. What azimuth value would you expect from something due north?