Magnetic fields on solar-type stars

December 12, 2014
Vivid orange streamers of super-hot, electrically charged gas (plasma) arc from the surface of the Sun reveal the structure of the solar magnetic field rising vertically from a sunspot. Astronomers are now studying the magnetic fields on solar-type stars using techniques of polarimetry. Credit: Hinode, JAXA/NASA

The Sun rotates slowly, about once every 24 days at its equator although the hot gas at every latitude rotates at a slightly different rate. Rotation helps to drive the mechanisms that power stellar magnetic fields, and in slowly rotating solar-type stars also helps to explain the solar activity cycle. In the case of solar-type stars that rotate much faster than does the modern-day Sun, the dynamo appears to be generated by fundamentally different mechanisms that, along with many details of solar magnetic field generation, are not well understood. Astronomers trying to understand dynamos across a range of solar-type stars (and how they evolve) have been observing a variety of active stars, both slow and fast rotators, to probe how various physical parameters of stars enhance or inhibit dynamo processes.

Most techniques used to observe stellar magnetism rely on indirect proxies of the field, for example on characteristics of the radiation emitted by atoms. Surveys using these proxies have found clear dependencies between rotation and the stellar dynamo and the star's magnetic cycles, among other things. Recent advances in instrumentation that can sense the polarization of the light extend these methods and have made it possible to directly measure solar-strength magnetic fields on other .

CfA astronomer Jose-Dias do Nascimento is a member of a team of astronomers that has just completed the most extensive polarization survey of stars to date. They detected magnetic fields on sixty-seven stars, twenty-one of them classified as solar-type, about four times as many solar-type stars as had been previously classified. The scientists found that the average field increases with the stellar rotation rate and decreases with stellar age, and that its strength correlates with emission from the stars' hot outer layers, their chromospheres. Not only does this paper represent the most extensive survey to date of its kind, it demonstrates the power of the polarization technique. It signals that it is possible to greatly expand the study of magnetic fields in solar-type stars, which efforts will continue to improve our understanding of the surface fields in the Sun.

Explore further: Sun-like stars reveal their ages

More information: "A BCool Magnetic Snapshot Survey of Solar-Type Stars," S. C. Marsden, P. Petit, S. V. Jeffers, J. Morin, R. Fares, A. Reiners, J.-D. do Nascimento Jr., M. Auriere, J. Bouvier, B. D. Carter, C. Catala, B. Dintrans, J.-F. Donati, T. Gastine, M. Jardine, R. Konstantinova-Antova, J. Lanoux, F. Lignieres, A. Morgenthaler, J.C. Ramırez-Velez, S. Theado, V. Van Grootel and the BCool Collaboration, MNRAS 444, 3517, 2014. adsabs.harvard.edu.ezp-prod1.h … /2014MNRAS.444.3517M

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cantdrive85
1.4 / 5 (10) Dec 12, 2014
Rotation helps to drive the mechanisms that power stellar magnetic fields,


Electric currents, and only electric currents, are the mechanisms that create stellar magnetic fields (and strength) and in turn the rotation (and speed) of stars. No tail wagging the dog here.
Maggnus
4.3 / 5 (12) Dec 12, 2014
Yep, magnetic field in the title means some stupidity by cantthinkforhimself. Laughingly predictable!!!
Captain Stumpy
4.6 / 5 (9) Dec 12, 2014
Yep, magnetic field in the title means some stupidity by cantthinkforhimself. Laughingly predictable!!!
@Maggnus
of course she is laughingly predictable... sad but true!
LOL

here are the studies on arXive (1 referenced above, the other is tied to it)
http://arxiv.org/...74v1.pdf
http://arxiv.org/...07v1.pdf

there are certain observed parameters that are more death knell tolling for the electric universe, but i am willing to bet you $100 that cd doesn't see it

Studies are interesting... a LOT of data... i am sifting through it now
Maggnus
4.6 / 5 (9) Dec 12, 2014
Hey Stumpy, here's another nail: — Neutrinos spotted from Sun's main nuclear reaction.

"Nearly all of the energy generated in the Sun involves a chain of nuclear reactions that begins with two protons fusing together to form deuterium along with a positron and a low-energy neutrino. Calculations predict that about 60 billion of these neutrinos pass through a square centimetre on Earth every second, but low-energy neutrinos are particularly difficult to detect and so the theory could not be verified. Now, deep under the Gran Sasso mountain in Italy, some of these neutrinos have been detected by spying the flashes of light that occur when the neutrinos collide with electrons in a giant tank of liquid." See http://www.scient...rexino/.

Not like another nail was needed. EU is outdated, debunked, pseudo-scientific garbage. That some continue to think it has any credibility is a sad testimony to scam artists' hold on the gullible.
cantdrive85
1.5 / 5 (8) Dec 12, 2014
Of course you are incorrectly assuming neutrinos are somehow supposed to not exist in the electric sun model. Fusion also occurs in the electric sun model, another fact conveniently ignored by the obfuscaters.
IMP-9
4.6 / 5 (9) Dec 12, 2014
Of course you are incorrectly assuming neutrinos are somehow supposed to not exist in the electric sun model.


You know as well as everyone else that there are a good 20 different electric sun ideas. First there were no neutrinos. Then the electric sun explained the neutrino problem. Then when neutrino oscillation was confirmed the electric sun model fit that too. What it doesn't explain is anything convincing like the specific reaction rates which the solar standard model predicts. A wonderfully bendy "theory" that can be made to fit any observation with a handwave.
Captain Stumpy
4.5 / 5 (8) Dec 12, 2014
Of course you are incorrectly assuming neutrinos are somehow supposed to not exist in the electric sun model. Fusion also occurs in the electric sun model, another fact conveniently ignored by the obfuscaters.
not what i am referring to sparky!

try again
(you can pay me with paypal if you like - i will give you one hint: it is basic physics that you can learn here in these freshman level courses: http://ocw.mit.ed...ll-2002/ AND
http://ocw.mit.ed...ng-2005/
And it completely debunks the electric star conjecture the electric universe guys give! )
ursiny33
1 / 5 (5) Dec 13, 2014
Star magnetic fields, are knocking off and replacing those electrons on atoms all the time in collisions of electrons, if the star has alot of heavy atoms in its core the compression and numbers of collisions are greater producing larger amounts of electron flow into field trains field lines in parallel of the magnetic field, and fission of atoms combining to make new element atoms is just one component in a stars heat and energy output, from turning protons into neutrons in the new atom discharging those positively charged high energy particles of the shell of a proton, the other main heat and energy generator is in the central core of the star where heat and pressure make those heavy volatile atoms reach their structural limits where the environmental conditions their make it impossible to stay stable enough to stay together, they lose their orbiting electrons in this part of the star and come apart ,and become a ball of super hot radioactive particles in a plasma field
Whydening Gyre
5 / 5 (5) Dec 13, 2014
Star magnetic fields, are knocking off and replacing those electrons on atoms all the time in collisions of electrons, if the star has alot of heavy atoms in its core the compression and numbers of collisions are greater producing larger amounts of electron flow into field trains field lines in parallel of the magnetic field, and fission of atoms combining to make new element atoms is just one component in a stars heat and energy output, from turning protons into neutrons in the new atom discharging those positively charged high energy particles of the shell of a proton, the other main heat and energy generator is in the central core of the star where heat and pressure make those heavy volatile atoms... ... stay stable enough to stay together, they lose their orbiting electrons in this part of the star and come apart ,and become a ball of super hot radioactive particles in a plasma field

Ursiny - I suggest coming back when you have sorted out your word salad...
ursiny33
1 / 5 (4) Dec 13, 2014
Whydening Gyre, are you a professional troll without ever having a genuine mechanical idea of your own ,or the professor of this thread, showing the glory of your intellect , if so the floor is yours why don't you enlighten us about the mechanical construction of the hydrogen atom, that would be a delightful lecture
Vietvet
5 / 5 (5) Dec 13, 2014
@ursiny33

Whydening Gyre, are you a professional troll without ever having a genuine mechanical idea of your own ,or the professor of this thread, showing the glory of your intellect , if so the floor is yours why don't you enlighten us about the mechanical construction of the hydrogen atom, that would be a delightful lecture


@Whyening Gyre's suggestion is valid. English must not be your native language. You get an A for effort but a D- for execution.
Whydening Gyre
5 / 5 (6) Dec 13, 2014
Whydening Gyre, are you a professional troll without ever having a genuine mechanical idea of your own ,or the professor of this thread, showing the glory of your intellect , if so the floor is yours why don't you enlighten us about the mechanical construction of the hydrogen atom, that would be a delightful lecture

Stringing a mishmash of technical jargon together in no particular order isn't all that original either. Many have preceded you.
ursiny33
1 / 5 (4) Dec 13, 2014
My perception so far is you have nothing to offer to the material of the article, you must be young immature fellers, with no concept of respectful behavior, using your electronic devices forms amusement to each other using those negatively charged particles called electrons on conductive materials to transfer into useless talk on this page, lets the only respect you have is for those with English degrees or PHDs next to their names I see, well the men who taught man powered fight were bicycle mechanics, and another feller named capernicus his lesson wasn't that he got the mechanics right about the earths orbit around the sun in his day before the physicists of his time it was the big picture of that observerable mechanics are sometimes the opposite of your comprehension, peace fellers
Whydening Gyre
5 / 5 (2) Dec 13, 2014
My perception so far is you have nothing to offer to the material of the article, you must be young immature fellers, with no concept of respectful behavior, using your electronic devices forms amusement to each other using those negatively charged particles called electrons on conductive materials to transfer into useless talk on this page, lets the only respect you have is for those with English degrees or PHDs next to their names I see, well the men who taught man powered fight were bicycle mechanics, and another feller named capernicus his lesson wasn't that he got the mechanics right about the earths orbit around the sun in his day before the physicists of his time it was the big picture of that observerable mechanics are sometimes the opposite of your comprehension, peace fellers

Eehhh,... wrong answer. 60 yr old, here... No PHD's. Just - an artist.....
Whydening Gyre
5 / 5 (3) Dec 13, 2014
I have no problem with proper postulations about the universe. Just with attempts at making word salad mumbo jumbo sound like something profound....

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