The Sun’s coronal tail wags its photospheric dog
The Sun’s coronal tail wags its photospheric dog
For Space News segment, Spring 2017
See the youtube segments at
Segment #1:
Segment #2:
The text below is an outline, which did not transfer over well from the previous blog platform. Sorry, no time to put all of this together :-( for the blog
Sunspots and Flares
A recent observation has called into question our basic understanding of solar flares and sunspots.
Figure 1sunspots seen by SOHO
Sunspots, viewed in visible light, are dark spots on the photosphere, which is, of course, why they are called sunspots. They were first observed with telescopes in the early 1600s. They come and go in greater and lesser numbers over the 11 year solar cycle.
They are about as big as planets
Figure 2 sunspot with image of the Earth overlayed to see size comparrison
Figure 3 Sunspot Image from UCAR, magnetic field image
Three hundred years after their discovery we were in for a big surprise when were able to send X-ray and Ultraviolet cameras up above the Earth’s atmosphere and look at sunspots. Above these cool, dark spots on the surface of the Sun are very high energy loops and streamers. Here is side view of a sunspot, showing X-ray emissions towering above it. The fact that we see X-rays above the sunspots means there are extremely high energies above the sunspots.
Figure 4 From Hinode, xray image above a sunspot
[It would be good if we could get some of this video in there:
https://en.wikipedia.org/wiki/File:AR1520_and_Shimmering_Coronal_Loops.ogv
]
Here is an SDO image in the far ultra-violet. You can see that above the surface, these sunspots are connected by towering loops of plasma. These are called coronal loops. They are very energetic.
Figure 5 coronal loops above sunspots seen by SDO 171nm
It is from these towering energetic loops that come the solar flares. Solar flares are some of the highest energy events in the solar system, and they happen when these coronal loops very quickly let go, or burst, and send out a large amount of energy.
With this brief introduction to sunspots and solar flares, we can now talk about the very surprising paper published by Chang Liu, on 24-Oct-2016. The paper is surprising because it completely calls into question the existing scientific understanding of the relationship between sunspots, coronal loops, and solar flares.
The commonly accepted view of the Sun is that all the energy comes from nuclear fusion happening deep in the center of the Sun, which energy then slowly makes its way out to the surface. Looking at things this way, it is then further assumed that all the energy in corona loops and flares ultimately comes from inside the Sun. Since the 1960s, all theories about solar flares have assumed that the energy for the flare comes from inside the Sun. But, up until quite recently, we did not have telescopes strong enough or fast enough to really prove or disprove that model of how things work.
This is why the results published in 2016 by Chang Liu’s team are so revolutionary. The data used in this paper were obtained with NST at Big Bear Solar Observatory, which is operated by the New Jersey Institute of Technology. The work is a joint effort by NASA, the Korea Astronomy and Space Science Institute and Seoul National University, and the Chinese Academy of Sciences. The data clearly show that the flare in the corona happens first, then there are large scale motions in the sunspot beneath. That sequence of events is not possible with our current models. All the flare models since the 1960s assume that the energy flow on the Sun only goes from inside out, never from outside in. This led Chang Liu to make what is now one of my favorite quotes in astronomy. He says, It’s analogous to the tail wagging the dog.
I will give some quotes from his discussion of the results:
"We used to think that the surface's magnetic evolution drives solar eruptions. Our new observations suggest that disturbances created in the solar outer atmosphere can also cause direct and significant perturbations on the surface through magnetic fields, a phenomenon not envisioned by any major contemporary solar eruption models. This has immediate and far-reaching implications in understanding energy and momentum transportation in eruptions on the Sun and other stars,"
“The sun’s outer layer, or corona, where flares are released, has a plasma density about a hundred million times smaller than that of the photosphere. “It’s analogous to the tail wagging the dog. The lower-density regions are much less energetic and forceful,”
“…by construction these [existing] models cannot address flare-induced sunspot motions, which were considered implausible…”
“we conclude that the observed sunspot rotation on the photosphere is a result, not a cause, of the flare magnetic reconnection in the corona, which challenges the conventional view of the photosphere-corona coupling during flares.”
[ The movie of this is in, called “3. Supplementary Movie 3”, at http://www.nature.com/articles/ncomms13104#supplementary-information ]
Theories, Models, and Data
I think Chang Liu is being both cautious and brave in these statements. Are the previous scientific models wrong? Yes, we now see they are wrong. All of them. But do the new observations disprove the entire theory that stars are powered from the inside? Not necessarily. Scientific thought exists in layers, or levels. We have theories. We have models. And we have data.
Theory
Models
Data
I stacked them vertically because these three aspects, theory models and data, are not of equal weight or equal power. Scientific theories, the top level, are what you might call BIG ideas. They set the overall framework for years of work where many scientists can create many models and do lots of experiments collecting lots of data. Scientific theories change very slowly, over centuries. The models change more quickly, and new data is coming in every day.
I have found that many non-scientists are not clear about the level of Models, which sits between Theory and Data. So I would like to make an analogy, to help clarify this.
Constitution
Take our political system in the United States. We have a fundamental idea called the Constitution. The Constitution changes very slowly, and if it changes fundamentally, then you basically have to start all over and make a new country. Inside the Constitution, which is the top level, there are statements such as that laws will be created by a body of representatives who are appointed or elected by the people. That simple, and very revolutionary, idea is analogous to a scientific Theory.
Constitution
Each State’s rules about electing representatives
The Constitutional requirement of representation can be implemented in many different ways. And in America most states have implemented that requirement each in their own way. The rules that each state chooses to follow are analogous to what I am calling scientific models. In science many different Models can be created that will satisfy the Theory. And in politics, many different ways can be enacted to elect representatives that will satisfy the Constitutional requirement. Many people understand this in the political realm. Just as most scientists whose work involves creating new Models understand they are usually not inventing new Theories, but are creating new Models that fit existing theories. But just as in politics, the science news media needs to simplify things, and if you only read the news headlines, you get the impression that there is only Theories and Data, with nothing in between. But that is not how science works. Scientists are always creating models, and those models are always within the larger framework of the prevailing scientific Theories of how our universe works.
Constitution
Each State’s rules about electing representatives
An election
Getting back to politics, each time we elect representatives, that is where the rubber meets the road, and our Constitution and the way each state has decided to do things actually gets tested and there are real results. In America, each time we elect representatives we are in essence doing another experimental run testing the grand theory that on this Earth there can be a group of people that will elect their leaders. If things go badly, as they sometimes do in the real world, and some election gets botched, we usually blame the data collection. That is, we first blame the election officials or the ballots or the counting process. But if things continue to go wrong, we might eventually begin questioning the nature of the way given State has implemented its version of this election process. And, I think you can see, it would take many, many botched elections before anyone would doubt the American Constitution.
Theory
Models
Data
Circling all the way back to the results by published by Chang Liu and his team, the data is impeccable. No one is doubting the data. We can all sit and watch it with our own eyes. The flare goes through and the sunspot rotation increases soon after. Chang is pointing out that here the data proves the existing models wrong. The existing models do not allow that a solar flare in the atmosphere could cause these large changes in the photosphere below. So at the very least, new models will need to be created. Chang is not saying that there is anything fundamentally wrong with our theories about how stars work.
Since the new data shows that the existing models are fundamentally incorrect – the observed behavior is actually impossible under the existing model - to my eye, this is yet another indication that we might want to reconsider the larger Theory that all energy and influence in our solar system comes only from the center of the Sun.
A New Cosmology
I am going to talk through some reasons why this new sunspot data is so important for our understanding of scientific theories and models. Current Theory- and I want to you to notice that I am using the word Theory which is the highest level on my diagram - says that each star in our great universe is isolated from every other star. Yes, you may not know that about mainstream cosmology, but, mainstream cosmology assumes that every star in our galaxy is isolated from every other star. Like our picture of a Medieval Lord, each isolated star creates its own energy only from within itself.
But if you entertain the idea that stars might be energetically connected to each other, if you entertain the idea that stars might receive energy from the Galaxy of which they are a part, just as cells in our own bodies receive sustenance from our bodies as a whole, then we have in our hands a very different scientific theory. I want to take a pause here, and say that again. If one wants to consider that stars might be energetically connected to each other, or that stars might receive input from the Galaxy, then we are embarking on a completely new scientific Theory.
We are at a point in cosmology where there are two world views. The old worldview, as I mentioned, sees all stars as energetically isolated. The new worldview says that stars are energetically connected, and can influence each other. The new worldview goes further to acknowledge different levels of energies. There are energies that exist at planetary levels, like weather, and lightning, and northern lights. And then there are energies that operate at the scale of stars – solar flares, the solar wind and Heliospheric current sheet. But there is also energies that operate at the level of Galaxies. And all these levels are connected. In the new worldview the planets receive solar energies and transform those or scale them down, so that lighting and weather on our planet are manifestations of what happens when a planet absorbs and digests solar energies. Just as a planet would be blown to smitherines if it were hit by the full power of a star, so would a single star be blown to bits if it were to ever receive the full energy of a galaxy. But individual stars can absorb and digest their small portion of these galactic energies. The stellar activities of solar flares and sunspots and solar wind are what happens when stars take in their small portion of galactic energies.
Asked if there is any data that might support such a new worldview, I can only say that much of the evidence has already been seen, but we have not known how to understand what we are seeing. We scoff at people several hundred years ago who thought the Earth was the center of all things. For a few hundred years now we have been thinking in terms of the Sun being the center of all things. So how are we reallky any better? It is time now to add another and larger level to our cosmology, and truly see that stars are part of a larger and more energetic world. Look for example at this wonderful image from the Hershel telescope.
Figure 6 ESA’s Herschel space observatory. It depicts the giant molecular cloud RCW106, a massive billow of gas and dust almost 12 000 light-years away
[Maybe also the close up]
Figure 7 Close up ESA’s Herschel image of the giant molecular cloud RCW106
We can see clearly that stars form on filaments – galactic filaments. I can tell you that none of the models in the old worldview predicted that – in fact, such a result would have been impossible. Here is a situation similar to Chang Lui’s paper – the old theories not only did not predict that stars would form this way, the old theories said it was impossible. Yet, in the new cosmology that I am trying to describe, this result was predicted by such theorists as Wal Thornhill long before the images started coming back from the Herschel telescope. He was able to predict exactly what the new telescopes show us because he was starting from a very different Theory of how galaxies and stars are related.
This infrared data is just one example. Fresh images and data are coming in every day of our Earth, of the other planets in our solar system, of planets that orbit other stars. When the recent results were published that a nearby star has seven planets orbiting it, all of which might harbor life, I asked my students, are you surprised that we are discovering that most stars have other planets orbiting? The vast majority of my students said, no, they were not surprised at all. I was very encouraged by this, because it shows they have an inherent sense that these sorts of hierarchies are to be expected. I encourage anyone out there to start looking at the wealth of new from NASA and ESA and other agencies. Look at the data from the point of view of a new cosmology.
Appendix, material
The reports in the literature
In a March 2016 article, published in Nature Communications, lead author Chang Liu
"We used to think that the surface's magnetic evolution drives solar eruptions. Our new observations suggest that disturbances created in the solar outer atmosphere can also cause direct and significant perturbations on the surface through magnetic fields, a phenomenon not envisioned by any major contemporary solar eruption models. This has immediate and far-reaching implications in understanding energy and momentum transportation in eruptions on the Sun and other stars,"
And in the review https://scienmag.com/the-suns-coronal-tail-wags-its-photospheric-dog/
“The sun’s outer layer, or corona, where flares are released, has a plasma density about a hundred million times smaller than that of the photosphere. “It’s analogous to the tail wagging the dog. The lower-density regions are much less energetic and forceful,” said Chang Liu”
In “Flare-induced Impulsive Sunspot Rotation caught in High Resolution”, Chang Liu, 24-Oct-2016 http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/Flare-induced_Impulsive_Sunspot_Rotation_caught_in_High_Resolution
“…by construction these models cannot address flare-induced sunspot motions, which were considered implausible…”
“we conclude that that the observed sunspot rotation on the photosphere is a result, not a cause, of the flare magnetic reconnection in the corona, which challenges the conventional view of the photosphere-corona coupling during flares.”
In “Unprecedented Fine Structure of a Solar Flare Revealed by the 1.6 m New Solar Telescope”, Ju Jing, Yan Xu, Wenda Cao, Chang Liu, Dale Gary & Haimin Wang. Received 16-Jan-2016, published 13-Apr-2016. http://www.nature.com/articles/srep24319#introduction
In the standard flare model3,4,5,6, the primary energy release and subsequent particle acceleration occur in the corona as a result of magnetic reconnection7. The precipitating nonthermal particles from the reconnection site, and thermal conduction from the reconnected loops, are two agents for transporting the energy released in the corona to the lower and denser chromosphere where most of the energy is finally converted into heat and radiated away as thermal emission8. However, many of the physical details of this standard model and subsequent processes are presently not well understood,…
The references 3,4,5,6 go back from 1964-1976. \