Hot, dense material surrounds O-type star with largest magnetic field known

September 23, 2015
The magnetic field of the O-type star called NGC 1624-2 is unusually large for its class. Credit: SOHO/[instrument] Consortium. SOHO is a project of international cooperation between ESA and NASA.

Observations using NASA's Chandra X-ray Observatory revealed that the unusually large magnetosphere around an O-type star called NGC 1624-2 contains a raging storm of extreme stellar winds and dense plasma that gobbles up X-rays before they can escape into space.

Findings from a team of researchers led by Florida Institute of Technology Assistant Professor Véronique Petit may help scientists better understand the lifecycle of certain , which are essential for creating metals needed for the formation of other stars and planets.

The findings will be published Sept. 23 in the journal Monthly Notices of the Royal Astronomical Society.

The massive O-type star - the hottest and brightest type of star in the universe - has the largest magnetosphere known in its class. Petit found NGC 1624-2's magnetic field traps gas trying to escape from the star and those gases absorb their own X-rays. The star's powerful stellar winds are three to five times faster and at least 100,000 times denser than our Sun's solar wind. Those winds grapple violently with the magnetic field and the trapped particles create the star's huge aura of hot, very .

"The magnetic field isn't letting its stellar wind get away from the star, so you get these big flows that are forced to collide head on at the magnetic equator, creating gas shock-heated to 10 million Kelvin and plenty of X-rays," said Petit, who was part of a team of scientists that discovered the star in 2012. "But the magnetosphere is so large that nearly 80 percent of these X-rays get absorbed before being able to escape into free space and reach the Chandra telescope."

The magnetic field at the surface of NGC 1624-2 is 20,000 times stronger than at the surface of our Sun. If NGC 1624-2 was in the center of our solar system, loops of dense, hot plasma would extend nearly to the orbit of Venus.

Only one in 10 massive stars have a . Unlike smaller stars like our sun that generate magnetism with an internal dynamo, magnetic fields in massive stars are "fossils" left over from some event in its early life, perhaps from a collision with another star.

Petit and her team, including Florida Tech graduate student Rebecca MacInnis, will know even more about the NGC 1624-2 in October after getting data back from the Hubble Space Telescope that will explore the dynamics of its trapped wind.

Explore further: Astronomers measure largest-ever magnetic field around massive star

More information: Monthly Notices of the Royal Astronomical Society, mnras.oxfordjournals.org/lookup/doi/10.1093/mnras/stv1741

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shavera
4.4 / 5 (13) Sep 23, 2015
Note: Here's astrophysicists doing work with plasmas and magnetic fields. Plasmas are not something astrophysicists ignore, don't understand, or are misinformed about. It's a very standard part of the science of astrophysics.

So when someone will inevitably show up, telling you about the work of some engineer from half a century ago, and how that invalidates all of modern science because astronomers simply don't think about how plasmas behave, they're full of it. They haven't spent one single second actually in the field or actually trying to understand what the real scientists do or say. They just want to push their own pet wishful thinking on the internet at large.
carlo_piantini
1.1 / 5 (7) Sep 23, 2015
Lol, shavera, you realize that *you're* always here, talking about either Alfven or EU ideas, before anyone else every shows up? It's your right, but, I find the irony of it a little bit funny.

I don't speak for anyone else here promoting interest in EU ideas (bschott, cantdrive, etc.), I only speak for myself. I've explained my personal interest/curiosity on the subject several times to everyone here: an allegation was raised and maintained by Alfven for about the majority of his later career, where he suggested that MHD theory was being misapplied - in particular, with the use of the "frozen-in" theory to magnetic field lines, the lack of double layers in our models, the lack of focus on E fields and currents, etc. Being one of the most influential plasma physicists in the 20th century, I'm inclined - as a student - to learn his material in full, right along with the rest of the primary astrophysical/plasma literature.
carlo_piantini
1.9 / 5 (7) Sep 23, 2015
That feels like that's a perfectly rational course to follow to me. His ideas are just another tool to keep in the toolbox. How could I, or anyone, possibly make an educated decision about the validity of his criticism unless both have been studied, and the evidence weighed? If that's been done by the astrophysical community, then great! They can maintain their consensus. But I'd like to investigate the situation myself, as an educated student, and make my own determination. When I post here, it's because new *observational* evidence suggests support for one of his hypothesis, which I find interesting. I'm not here posting that the entire EU clan is right in every one of their propositions; they're definitely not. But they've got interesting ideas, and so did Alfven and Birkeland, and they should at least be explored. That's how I see it, anyway.
shavera
4.5 / 5 (8) Sep 23, 2015
Why I'm always trying to be here first is because I really don't want to get bogged down in the specific details of how is wrong. There are far more ways to describe reality incorrectly than correctly, and so devoting a lot of time to understanding wrong ideas just to refute them is... not what I want to do with my time.

As you say, though, Alfven made the claim that physicists don't consider double layers, or use "frozen" magnetic field lines. What evidence is there that this claim is true? Even if we should find that astrophysics often uses "frozen" magnetic field lines, for example, it's pretty probable that the researchers have an explanation as to why they chose that model.
shavera
4.1 / 5 (9) Sep 23, 2015
I think that mostly, the whole discussion falls on laziness of the EU side. They never bother to read through the textbooks of modern physics and astrophysics. They don't read the work that leads scientists to think what they think. And they tend to just snipe from a distance about the people who have done that work and that reading that they're some kind of preachers of a dogma, resistant to new ideas. When, really, scientists are remarkably open to new ideas, so long as they're well founded on observation and predictive power.

Why shouldn't it go the other way round? Well because like I said, there are many more ways to get things wrong than right. No one could survive long in science trying to learn every crackpot/discredited theory, and why, exactly it's wrong. I don't want to type out a whole treatise on the fact, esp. with limited characters, so I'll just summarize that if any of the crackpots on here actually did science, they would see the act of doing science differently.
carlo_piantini
1.8 / 5 (6) Sep 23, 2015
There are far more ways to describe reality incorrectly than correctly, and so devoting a lot of time to understanding wrong ideas just to refute them is... not what I want to do with my time.


Let me first say this: I'd argue, and I actually think most astrophysicists would agree, that the majority of Alfven's work - that which deals with the plasma physics of the *solar system* - is largely held as correct. The present astrophysical community uses a very large portion of his work, which was born out as correct via direct in-situ measurements, and lab experiment. The case can be argued that this use of his ideas comes without credit to the man, and said argument has been made already: http://adsabs.har...20..577B

To lump the entirety of Alfven's work as "wrong ideas" is, in itself, incorrect.
carlo_piantini
1.7 / 5 (7) Sep 23, 2015
The contention with Alfven's ideas lies mostly with his general ideas on plasma physics in the galactic scale and above, all the way up to a general cosmology for the entire Universe. These ideas were rejected in the 80s-90s, when the evidence in general did not support his overall cosmological ideas, or his ideas on galaxy formation. This was 20+ yrs ago. And while I do not agree, or particularly have any interest, in his ideas on overall cosmology, there has been - at least in my view - a large amount of *observational* evidence coming from Herschel, Alma, the VLA, etc. that supports his general ideas on galaxy formation. So, I am interested in studying them.
carlo_piantini
1.8 / 5 (6) Sep 23, 2015
As you say, though, Alfven made the claim that physicists don't consider double layers, or use "frozen" magnetic field lines. What evidence is there that this claim is true?


I'm not sure! Which is the entire point of why I'm interested in investigating the issue in general. If you'd like, you could read a piece published by Alfven in '77, discussing the issue of the frozen-in problem, here: http://www.iaea.o...1834.pdf

Essentially, for the field line to be frozen in, the E-field running parallel to the field line needs to be 0, i.e. there is no current, and the field line is frozen in. To meet that condition, the conductivity of the plasma needs to be nearly infinite. In most plasmas, this condition seems to be satisfied simply by the density of the plasma, but he outlines four main issues where this condition is actually commonly broken down.

carlo_piantini
1.5 / 5 (4) Sep 23, 2015
I think that mostly, the whole discussion falls on laziness of the EU side. They never bother to read through the textbooks of modern physics and astrophysics.


I actually *agree* with this idea, and if you ever find me posting on the TB forum as "BecomingTesla", you'll see me raise this point. If they ever want to be taken seriously - if their arguments are even legitimate, I honestly don't know if they are and the mainstream community has their consensus already - then they need to devote way more time to (a) building a cohesive, solid framework of all their ideas, how they're connecting, the explicit evidence for them, etc. (b) comparing this framework, directly, to the published astrophysical literature to either validate or invalidate Alfven's criticism and (c) just get in the lab, and do significantly more work. The SAFIRE experiment is just that, and it looks very, very promising at least to me.
plasmasrevenge
1 / 5 (3) Sep 24, 2015
Re: "I'm inclined - as a student - to learn his material in full, right along with the rest of the primary astrophysical/plasma literature."

Good for you. It's only by running claims back and forth between theorists and their critics that the controversy can be mapped out and the debate can be rationally engaged. What is outright peculiar is that this activity does not appear to occur in academic circles, and my prediction is that the universities will in due time regard this as a very serious mistake, as it opens the door for somebody outside of academia to solve the problem. They will predictably lose control over the study of scientific controversies with the current approach, and this loss will come to haunt the entire academic enterprise.

Of course, anybody reading this article that is aware of Alfven will recognize the silly suggestion that stellar magnetic fields can be "fossils". How does this work again?
plasmasrevenge
1 / 5 (4) Sep 24, 2015
Re: "The contention with Alfven's ideas lies mostly with his general ideas on plasma physics in the galactic scale and above"

Yes, and the truly embarrassing part is that the debate that Alfven started over how to model cosmic plasmas which rages unresolved, to this day, between The Astrophysical Journal and IEEE's Transactions on Plasma Science, is still not actually taught to the graduate students who are learning plasma physics.

That is the most revealing aspect of the controversy for those of us in the public who are looking in at how academia believes that it has handled this issue. Much of the graduate program "training" is actually intended to create disciplined thinkers who will adhere to the MHD ideology. The programs accomplish this by forcing the students to memorize equations -- many of which we already know to be incorrectly applied to astronomical observations. Jeff Schmidt spilled the beans on the approach with Disciplined Minds.
bschott
1 / 5 (1) Sep 24, 2015
I don't speak for anyone else here promoting interest in EU ideas (bschott, cantdrive, etc.),


I have actually emailed you personally and told you that the EU has no fundamental basis for what they believe...and I actually take offense that you just mentioned my name next to that idiots.

For the record yet again, the EU are as delusional as Shavers opening line in this set of posts.
carlo_piantini
3 / 5 (2) Sep 24, 2015
I have actually emailed you personally and told you that the EU has no fundamental basis for what they believe...and I actually take offense that you just mentioned my name next to that idiots.


No offense intended, and honestly there's no need for you to insult other people. My mistake, it is in fact correct that you don't promote EU ideas. You regularly advocate the need for a different paradigm in how cosmic plasmas are treated, so I lumped you with them due to a lack of attention.
bschott
1 / 5 (1) Sep 24, 2015
Carlo - This site is populated with fanatics...admittedly I am one regarding magnetism. With fanaticism come exchanges that regularly elevate (or deteriorate) into heated discussions and insults. CD85 is also fanatical...about the EU. My exchanges with him have resulted in me feeling that way about him, most of the people here who hate my guts also feel this way about him for the same reasons.

Thank you for recognizing your mistake, and for your even keel approach to your comments regardless of what you have walked into in the comments sections.
katesisco
not rated yet Sep 29, 2015
Non scientist post: this large magnetic field --could it be a disintegrated neutron star? Would it be possible to rob a neutron star of its magnetism? since we dont understand the relationships between gravity and magnetism?

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