The Sun's Rotation: A Deeper Look

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Discussion Overview

The discussion revolves around the rotation of the Sun, specifically whether it rotates as a solid body or if its interior layers spin at different rates. Participants explore the implications of these rotational dynamics, particularly in relation to the core and outer layers, and the observational consequences of these behaviors.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose that the Sun exhibits differential rotation, with the outer layers rotating more quickly at the equator than at the poles, while below the tachocline, the rotation resembles that of a rigid body.
  • One participant mentions the role of helioseismology in understanding the Sun's rotation.
  • Another participant expresses interest in the evolution of core rotation, particularly in relation to stars nearing supernova, and questions whether stellar cores 'spin up' before detonation.
  • There is a query about the specifics of layer rotation, including whether it refers to spherical shells, types of burning, or convection processes.
  • One participant discusses the challenges of explaining pulsar spins without invoking recoil, suggesting that lateral motion does not account for the observed tangential spins.

Areas of Agreement / Disagreement

Participants express varying viewpoints on the nature of the Sun's rotation, with some agreeing on the concept of differential rotation while others raise questions about the specifics of layer interactions and core dynamics. The discussion remains unresolved regarding the mechanisms behind core rotation and pulsar spins.

Contextual Notes

Limitations include the dependence on observational data from helioseismology and the complexity of modeling the Sun's internal dynamics, which may not fully account for all variables involved in core rotation and its implications.

Chronos
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A curious thought. We know the sun rotates [spins]. Does it rotate like a solid body, or do the interior layers spin at different rates? If so, does the 'core' of a sun rotate faster or slower than the outer layers? Is it as difficult to calculate this as I suspect it might be? What would be the observational consequences?
 
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Chronos said:
A curious thought. We know the sun rotates [spins]. Does it rotate like a solid body, or do the interior layers spin at different rates? If so, does the 'core' of a sun rotate faster or slower than the outer layers? Is it as difficult to calculate this as I suspect it might be? What would be the observational consequences?

Inside the Sun there's a surface called tachocline that is at a radius of approximately 0'7 solar radius. Outside of this radius, the sun rotates differentially, more quickly at the equator than at the poles. Below the tachocline, the rotation of the sun is practically that of a rigid body
 
Thanks meteor and Nereid! This question was inspired by a far more sinister question [which is still a WIP] regarding a fairly unrelated matter and was hoping for a little help [I have lazy moments]. As it turns out [according to what I found so far], if you treat the whole thing as a rigid body, you should be at least within an OOM of the right result.
 
when you say "do layers rotate at different rates" are you talking about spherical shells, the different types of burning OR also convection?
 
I am specifically interested in the evolution of core rotation. Reasons to follow.
 
Insightful

neurocomp2003 said:
when you say "do layers rotate at different rates" are you talking about spherical shells, the different types of burning OR also convection?
My main interest is in the core spin of stars about to go supernova. Your comment is very insightful. I am wondering if stellar cores 'spin up' just before they detonate. I'm trying to figure out pulsar spins and looking for a mechanism that does not require recoil. Recoil does not seem to work because it appears to be mostly lateral, not tangential. Proper motion, especially in binary pairs, just do not seem to explain it. So I'm trying to come up with a reason.
 
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