Question on how sunspots move

[Dan T]

I’m new to this site, and I’ve been watching the 2993/2994 groups with great fascination. My question, though, applies to all sunspot activity, so I thought it more appropriate for an independent topic.   

One thing that surprised me was that sunspots move in a tight formation. Prior to this I would have assumed they floated across the surface, like leaves in a moving stream, occasionally colliding and triggering flares. That’s clearly not the case. 

My question is: What are the prevailing theories on why they move as they do? Are they “moored” to something below, that pulls them along? I haven’t come across an explanation for this in any of my reading. 

Thanks for any insight you can provide.

[Psyo]

1 hour ago, Dan T said:

I’m new to this site, and I’ve been watching the 2993/2994 groups with great fascination. My question, though, applies to all sunspot activity, so I thought it more appropriate for an independent topic.   

One thing that surprised me was that sunspots move in a tight formation. Prior to this I would have assumed they floated across the surface, like leaves in a moving stream, occasionally colliding and triggering flares. That’s clearly not the case. 

My question is: What are the prevailing theories on why they move as they do? Are they “moored” to something below, that pulls them along? I haven’t come across an explanation for this in any of my reading. 

Thanks for any insight you can provide.

If I am understanding your question correctly, the movement of the sunspots is due to the rotation of the sun. The sun completes a rotation every ~27 days. I don't know if sunspots move independently since I am new here as well and am still learning, so If anyone wants to add anything I would be delighted.

Edited April 30, 2022 by Psyo

[Archmonoth]

I have a limited understanding. There is Sunspot movement due to rotation, and the equator moves at a difference speed than the poles, so there is some turbulence from the 2 different speeds. 

 

From the Wiki: Solar rotation - Wikipedia

"The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at different periods. The source of this differential rotation is an area of current research in solar astronomy.^[1] The rate of surface rotation is observed to be the fastest at the equator (latitude φ = 0°) and to decrease as latitude increases. The solar rotation period is 24.47 days at the equator and almost 38 days at the poles. The average rotation is 28 days."

 

Perhaps this helps!

[Dan T]

Thank you for the reply, Psyo.

I supposed a better question would be why the spots appears to remain geostationary (heliostationary?) and move at the same rate as the sun? 

I know there's a lot more we don't understand about the sun than we do, but it is fascinating to study.

1 minute ago, Archmonoth said:

I have a limited understanding. There is Sunspot movement due to rotation, and the equator moves at a difference speed than the poles, so there is some turbulence from the 2 different speeds. 

 

From the Wiki: Solar rotation - Wikipedia

"The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at different periods. The source of this differential rotation is an area of current research in solar astronomy.^[1] The rate of surface rotation is observed to be the fastest at the equator (latitude φ = 0°) and to decrease as latitude increases. The solar rotation period is 24.47 days at the equator and almost 38 days at the poles. The average rotation is 28 days."

 

Perhaps this helps!

Thank you, Archmonoth. I posted a follow up question clarifying my original post. I'm suppose the issue is I'm thinking of the sun as a terrestrial object, and the sunspots as moons, but I don't think that applies here.

[Archmonoth]

6 hours ago, Dan T said:

I'm suppose the issue is I'm thinking of the sun as a terrestrial object, and the sunspots as moons, but I don't think that applies here.

Well, this is the place to learn about the Sun and see all sorts of weird stuff! For example, the Sun's rotation can be described further in a group of spherical harmonics called So^3 Spherical harmonics - Wikipedia (might be a bit off topic)

 

Stars and gas giants (Jupiter) move and rotate in many kinds of ways. (Like Parker Spirals)

Also, welcome to Space Weather Live! 

Edited May 1, 2022 by Archmonoth

[Cmags]

On 4/30/2022 at 11:55 AM, Dan T said:

I’m new to this site, and I’ve been watching the 2993/2994 groups with great fascination. My question, though, applies to all sunspot activity, so I thought it more appropriate for an independent topic.   

One thing that surprised me was that sunspots move in a tight formation. Prior to this I would have assumed they floated across the surface, like leaves in a moving stream, occasionally colliding and triggering flares. That’s clearly not the case. 

My question is: What are the prevailing theories on why they move as they do? Are they “moored” to something below, that pulls them along? I haven’t come across an explanation for this in any of my reading. 

Thanks for any insight you can provide.

I am also very interested in this topic. I wanted to layer in another questions which I seek clarity on... wasn't sunspot complex 2993/2994 born from previous sunspot 2975? I was just looking back at 2975's activity and far side journey before 2993/2994 emerged, and it appears this most recent complex was born from the former. Am I correct about this? 

[Marcel de Bont]

22 minuten geleden, Cmags zei:

I am also very interested in this topic. I wanted to layer in another questions which I seek clarity on... wasn't sunspot complex 2993/2994 born from previous sunspot 2975? I was just looking back at 2975's activity and far side journey before 2993/2994 emerged, and it appears this most recent complex was born from the former. Am I correct about this? 

From the top of my memory I think 2975 and 2976 survived the far side and were renamed 2993 and 2994. I am sure someone will correct me if I am wrong but those should be the numbers.

[Dan T]

25 minutes ago, Cmags said:

I am also very interested in this topic. I wanted to layer in another questions which I seek clarity on... wasn't sunspot complex 2993/2994 born from previous sunspot 2975? I was just looking back at 2975's activity and far side journey before 2993/2994 emerged, and it appears this most recent complex was born from the former. Am I correct about this? 

Thank you for your reply. I’m hoping to gain more insight into what keeps the spots more or less heliostationary (a word I may have made up). Certainly they grow in size and complexity, but I’m really interested to know what forces may be causing that. 

[Drax Spacex]

On 4/30/2022 at 10:55 AM, Dan T said:

One thing that surprised me was that sunspots move in a tight formation. Prior to this I would have assumed they floated across the surface, like leaves in a moving stream, occasionally colliding and triggering flares. That’s clearly not the case. 

My question is: What are the prevailing theories on why they move as they do? Are they “moored” to something below, that pulls them along? I haven’t come across an explanation for this in any of my reading. 

Thanks for any insight you can provide.

One could say that the sunspots are floating on the surface of the sun, and they do also appear to bubble up and submerge - having a radial or depth component.  And like the leaves In a stream that move faster in the center of the stream and slower along the edges of the stream, sunspots move faster along the equator of the Sun and slower nearer the poles of the Sun.  Not sure if there is a physical analogy there, but it does provide a memory aid for sunspot speed as a function of latitude.

Edited May 2, 2022 by Drax Spacex

[Dan T]

16 hours ago, Drax Spacex said:

One could say that the sunspots are floating on the surface of the sun, and they do also appear to bubble up and submerge - having a radial or depth component.  And like the leaves In a stream that move faster in the center of the stream and slower along the edges of the stream, sunspots move faster along the equator of the Sun and slower nearer the poles of the Sun.  Not sure if there is a physical analogy there, but it does provide a memory aid for sunspot speed as a function of latitude.

Thank you- that explanation makes a lot of sense. Analogies always help.

[KW2P]

Reading the comments above, I thought I'd emphasize that sunspots are not thin surface features floating independently like leaves on a stream. They are the surface manifestation of convection columns that go much deeper in the outer layer of the sun. Kind of like a cumulus cloud is the visible manifestation at the top of a convection column of air that starts at the surface of the earth.  The present understanding is the convective (up and down) flow of plasma. which is conductive, generates the magnetic fields we see by the process of MHD (magnetohydrodynamics).  See https://en.wikipedia.org/wiki/Magnetohydrodynamics

So sunspots are definitely going to rotate around the sun at the speed appropriate for their latitude since they aren't independent things, just our "end on view" of a deep convection system.

I hope that makes sense.

[Dan T]

49 minutes ago, KW2P said:

Reading the comments above, I thought I'd emphasize that sunspots are not thin surface features floating independently like leaves on a stream. They are the surface manifestation of convection columns that go much deeper in the outer layer of the sun. Kind of like a cumulus cloud is the visible manifestation at the top of a convection column of air that starts at the surface of the earth.  The present understanding is the convective (up and down) flow of plasma. which is conductive, generates the magnetic fields we see by the process of MHD (magnetohydrodynamics).  See https://en.wikipedia.org/wiki/Magnetohydrodynamics

So sunspots are definitely going to rotate around the sun at the speed appropriate for their latitude since they aren't independent things, just our "end on view" of a deep convection system.

I hope that makes sense.

It definitely makes sense. I like your cloud analogy even better than my leaf analogy (though I know they are all flawed). Thank you for your feedback. 

[KW2P]

On 5/3/2022 at 1:50 PM, Dan T said:

It definitely makes sense. I like your cloud analogy even better than my leaf analogy (though I know they are all flawed). Thank you for your feedback. 

It's not a great analogy but it has some similarities. We are in the position of someone observing Earth from space, seeing the tops of clouds and trying to puzzle out what's going on below the clouds. Clouds are just an artifact of what's really going on.