# Why does the sun travel faster about its equator?

1. Jun 17, 2009

### Ian_Brooks

Would this be valid for all other planets as well?

2. Jun 17, 2009

### xxChrisxx

Angular velocity depends on radius (distance from axis of rotation) so i'll say yes.

3. Jun 17, 2009

### Ian_Brooks

Hmmm - so if we considered the the sun moving (rotating) with constant speed, then in the xy plane a point about the equator would have to cover more distance than at the poles. Therefore the point about the equator would be traveling faster than at the poles to maintain the same speed.

ahh that makes more sense. Thanks

Last edited: Jun 18, 2009
4. Jun 17, 2009

### xxChrisxx

Yes, and the equator is further away from the axis of rotation that other parts. Ignore the word radius in my previous post, the bit in the brackets is all that matters.

5. Jun 18, 2009

### Ian_Brooks

thanks

6. Jun 18, 2009

### Staff: Mentor

Completely off. Linear velocity depends on the distance from axis, angular velocity should be constant.

And in the case of Sun there is an anomaly - angular speed at the equator is higher than the speed at other lattitudes. No idea why, but it is an observable fact. Equator rotates in 25 days, rotation at 75 deg lattitude takes 36 days.

7. Jun 18, 2009

### Ian_Brooks

this is what I came across on a documentary about fusion energy and the sun. So my reasoning above is way off then?

Where could I look for proposed theories describing why the sun undergoes this anomaly.

After watching the documentary last night I kept thinking to myself
"if all bodies move at a constant velocity how can points on the equator travel faster"

That was the best I could come up with above.

8. Jun 18, 2009

### Ian_Brooks

ok this is what I'm having troubles understanding

I posted this here thinking it was something fundamental that I should have known - thus saving myself from embarrassment at the hands of the astrophysics subsection.
- but I guess it would be better if the thread was now moved there

The question i wanted to lead up to was

I wanted to find out how the sun maintains the same over all temperture when we have the variability of sun spot occurence and solar flares hurling mass and energy out of the body of the sun.

What am i missing?

Last edited: Jun 18, 2009
9. Jun 18, 2009

### xxChrisxx

Well all i've got to say is... oops. I did acutally mean tangential velocity, i'm going to blame the fact that it was late and/or im in idiot on the error.

It's clear that the op's question is going beyond the simple rotation of a sphere, so i'll bow out for now as I know bugger all about the sun. I'll try asking my brother who looked at something similar to the OP's second question in his dissertation.

10. Jun 18, 2009

### Staff: Mentor

Happens to everyone :uhh:

11. Jun 19, 2009