Degrees of Arc

[ads8525]

Does anyone know where I can find the info to this:

 

How many degrees of arc does a star move in an hour? Also, does it matter how far north or south the star is.

[doG]

Well, the North Star is named that because it appears to hang over the north pole with the rest of the sky revolving around it (for northern hemisphere viewers that is). Stars in the equatorial plane appear to move the fastest. What is it that causes this apparent motion?

[swansont]

The earth goes 360 degrees in just under 24 hours.

[John Cuthber]

There's a fairly popular theory that says the stars don't move, but the earth does.

One fairly nearby star seems to travel 360 degrees in 24 hours. The pole star hardly seems to move at all. The others generally come pretty close to somewhere in between.

[Klaynos]

There's a fairly popular theory that says the stars don't move, but the earth does.

 

IT'S A LIE!!!

[ads8525]

If the Earth moves at 360 degrees in 24 hour that would be 15 degrees per hour. Since the stars don't actually move, their arc degree has to be 15 degrees per hour, as well as the Sun? The reason why the stars more North seem to move slower is becuase the stars are postioned almost directly over the northern hemisphere. Since the Earth rotates on its axis counter clockwise the stars in the northern hemisphere pretty much stay in the same postion. Am I on the right track?

[Mr Skeptic]

That's about right. You should be clear as to counter clockwise from which direction though (best use east and west). The earth actually spins a tiny bit slower than 360 degrees per day, making up for that with its motion around the sun as far as days are concerned.

 

Edit: fixed. Thanks doG.

[doG]

The earth actually spins a tiny bit slower than 360 degrees per hour, making up for that with its motion around the sun as far as days are concerned.

 

Did you mean 'per day'?

[swansont]

That's about right. You should be clear as to counter clockwise from which direction though (best use east and west). The earth actually spins a tiny bit slower than 360 degrees per day, making up for that with its motion around the sun as far as days are concerned.

 

Edit: fixed. Thanks doG.

 

And did you mean "faster?" The earth actually spins just under 361º per solar day.

[doG]

And did you mean "faster?" The earth actually spins just under 361º per solar day.

 

Yes but the OP asked about the speed of the stars so I would think you should use a sidereal day for this which is a true 360º rotation relative to the stars...

[swansont]

Yes but the OP asked about the speed of the stars so I would think you should use a sidereal day for this which is a true 360º rotation relative to the stars...

 

Which means it takes just under an hour to go 15º. I was assuming the small difference was not coming into play.