Sun's rotational speed

Greetings.

According to Wikipedia, the star Altair "is most notable for its extremely
rapid rotation; by measuring the width of its spectral lines, it was
determined that its equator does a complete rotation in about 6 1/2 hours.
In comparison, our star, the Sun, requires a little more than 25 days for a
complete rotation."

I wonder, would there be any observable effects to us here on earth if our
sun started rotating at this speed? Would a significantly faster rotation
affect the sun's appearance, or the earth's temperature, or planetary
orbits?

Regards,
Tristan

--
_
_V.-o Tristan Miller [en,(fr,de,ia)] Space is limited
/ |`-' -=-=-=-=-=-=-=-=-=-=-=-=-=-=-= In a haiku, so it's hard
(7_\\ http://www.nothingisreal.com/ To finish what you

On Mon, 22 Sep 2003 14:27:11 +0100, Tristan Miller wrote:

Greetings.

According to Wikipedia, the star Altair "is most notable for its
extremely rapid rotation; by measuring the width of its spectral lines,
it was determined that its equator does a complete rotation in about 6
1/2 hours. In comparison, our star, the Sun, requires a little more than
25 days for a complete rotation."

I wonder, would there be any observable effects to us here on earth if
our sun started rotating at this speed? Would a significantly faster
rotation affect the sun's appearance, or the earth's temperature, or
planetary orbits?

A very fast rotating star would become fatter at the equator, i.e., get an
oblate shape. This has been observed for Achermer (alpha Eridani) &
Altair. See : MacRobert A, The flattest star, Sky & Telescope (September)
2003; 106 (3): 20

--

Gautam Majumdar

On Mon, 22 Sep 2003 14:27:11 +0100, Tristan Miller wrote:

Greetings.

According to Wikipedia, the star Altair "is most notable for its
extremely rapid rotation; by measuring the width of its spectral lines,
it was determined that its equator does a complete rotation in about 6
1/2 hours. In comparison, our star, the Sun, requires a little more than
25 days for a complete rotation."

I wonder, would there be any observable effects to us here on earth if
our sun started rotating at this speed? Would a significantly faster
rotation affect the sun's appearance, or the earth's temperature, or
planetary orbits?

A very fast rotating star would become fatter at the equator, i.e., get an
oblate shape. This has been observed for Achermer (alpha Eridani) &
Altair. See : MacRobert A, The flattest star, Sky & Telescope (September)
2003; 106 (3): 20

--

Gautam Majumdar

Tristan Miller wrote in
:

Greetings.

According to Wikipedia, the star Altair "is most notable for its
extremely rapid rotation; by measuring the width of its spectral
lines, it was determined that its equator does a complete rotation in
about 6 1/2 hours. In comparison, our star, the Sun, requires a little
more than 25 days for a complete rotation."

I wonder, would there be any observable effects to us here on earth if
our sun started rotating at this speed? Would a significantly faster
rotation affect the sun's appearance, or the earth's temperature, or
planetary orbits?


The sun would be a lot more oblate if it was rotating at that speed. That
would result in more enhanced advance of the perihelions of the planetary
orbits, especially Mercury's. Other than that you would have to look at
detailed models. e.g the solar activity cycle is thought to be driven in
part by the sun's differential rotation (i.e it doesn't rotate as a solid
body). If the overall rotation rate was much higher it would probably
result in some differences to the activity cycle but that is just a
guess.


The point is moot, since you have conservation of angular momentum, the
sun isn't going to suddenly speed up. The stars with high rates of
rotation would have formed that way.

Rgds Llanzlan.



Regards,
Tristan

Tristan Miller wrote in
:

Greetings.

According to Wikipedia, the star Altair "is most notable for its
extremely rapid rotation; by measuring the width of its spectral
lines, it was determined that its equator does a complete rotation in
about 6 1/2 hours. In comparison, our star, the Sun, requires a little
more than 25 days for a complete rotation."

I wonder, would there be any observable effects to us here on earth if
our sun started rotating at this speed? Would a significantly faster
rotation affect the sun's appearance, or the earth's temperature, or
planetary orbits?


The sun would be a lot more oblate if it was rotating at that speed. That
would result in more enhanced advance of the perihelions of the planetary
orbits, especially Mercury's. Other than that you would have to look at
detailed models. e.g the solar activity cycle is thought to be driven in
part by the sun's differential rotation (i.e it doesn't rotate as a solid
body). If the overall rotation rate was much higher it would probably
result in some differences to the activity cycle but that is just a
guess.


The point is moot, since you have conservation of angular momentum, the
sun isn't going to suddenly speed up. The stars with high rates of
rotation would have formed that way.

Rgds Llanzlan.



Regards,
Tristan

It may or may not be possible for OUR sun to spin that fast, it probably
depends on mass.
For example pulsar can spin once per second.

I suspect any visibly noticable shape change (ie lets say 5%) would make sun
unstable and perhaps planet can come out from it.

Anyway, chances are faster spin create bigger solar flair as well as more
magnitism. Also more nuclear reaction.




"Tristan Miller" wrote in message
...
Greetings.

According to Wikipedia, the star Altair "is most notable for its extremely
rapid rotation; by measuring the width of its spectral lines, it was
determined that its equator does a complete rotation in about 6 1/2 hours.
In comparison, our star, the Sun, requires a little more than 25 days for
a
complete rotation."

I wonder, would there be any observable effects to us here on earth if our
sun started rotating at this speed? Would a significantly faster rotation
affect the sun's appearance, or the earth's temperature, or planetary
orbits?

Regards,
Tristan

--
_
_V.-o Tristan Miller [en,(fr,de,ia)] Space is limited
/ |`-' -=-=-=-=-=-=-=-=-=-=-=-=-=-=-= In a haiku, so it's hard
(7_\\ http://www.nothingisreal.com/ To finish what you

It may or may not be possible for OUR sun to spin that fast, it probably
depends on mass.
For example pulsar can spin once per second.

I suspect any visibly noticable shape change (ie lets say 5%) would make sun
unstable and perhaps planet can come out from it.

Anyway, chances are faster spin create bigger solar flair as well as more
magnitism. Also more nuclear reaction.




"Tristan Miller" wrote in message
...
Greetings.

According to Wikipedia, the star Altair "is most notable for its extremely
rapid rotation; by measuring the width of its spectral lines, it was
determined that its equator does a complete rotation in about 6 1/2 hours.
In comparison, our star, the Sun, requires a little more than 25 days for
a
complete rotation."

I wonder, would there be any observable effects to us here on earth if our
sun started rotating at this speed? Would a significantly faster rotation
affect the sun's appearance, or the earth's temperature, or planetary
orbits?

Regards,
Tristan

--
_
_V.-o Tristan Miller [en,(fr,de,ia)] Space is limited
/ |`-' -=-=-=-=-=-=-=-=-=-=-=-=-=-=-= In a haiku, so it's hard
(7_\\ http://www.nothingisreal.com/ To finish what you

The sun spinning so slow should have a wobble?? Like a slow spinning
top. Could the part of the nebular the star is created from be the
answer why stars all have different spinning rates. If that is true
stars created in the middle of the cloud should spin faster. Could
faster spin add to the stars mass? It adds to its inertia,and inertia
and gravity are the same thing.(equivalent Einstien) I guess you could
say the energy(motion) of the universe is just as important as its
matter. One physicist even said it was more important. Bert

The sun spinning so slow should have a wobble?? Like a slow spinning
top. Could the part of the nebular the star is created from be the
answer why stars all have different spinning rates. If that is true
stars created in the middle of the cloud should spin faster. Could
faster spin add to the stars mass? It adds to its inertia,and inertia
and gravity are the same thing.(equivalent Einstien) I guess you could
say the energy(motion) of the universe is just as important as its
matter. One physicist even said it was more important. Bert

"G=EMC^2 Glazier" wrote in message
...
The sun spinning so slow should have a wobble?? Like a slow spinning top.
Not really, wobble is cause by fact that top is not in low enegy state.
Thus during transition
from enough spin and angular momentum to hold it up...

If it was in outer space, it can spin very very slowly without type of
wobble you see on earth.


Could the part of the nebular the star is created from be the
answer why stars all have different spinning rates. If that is true
stars created in the middle of the cloud should spin faster. Could
faster spin add to the stars mass?

While it does add, it is NOT significant.probably... unless pulsar.

I saw some TV program where so called INNER galaxies are more likely to be
spiraling while
outer galaxies are less. This suggest to me that chances are galaxies does
not need spin to form, and rather interaction between galaxies causes spin,
this would also explain galaxies that have spiral are usually in plane.

It adds to its inertia,and inertia
and gravity are the same thing.(equivalent Einstien) I guess you could
say the energy(motion) of the universe is just as important as its
matter. One physicist even said it was more important. Bert



I dont believe in ONE bigbang.... Perhaps there are tons of black hole and
so call big bang and out observable universe is just a collision of 2 big
black holes.

Alternative I can believe is.... Black holes are UNIVERSES. Imagine even
horizons are bidirectional. Things fall in black hole and if you look at it
from other side, it is exploding from point. In other word, we tend to
think of black hole as sphere of event horizon... but due to TIME inside is
infinite space.