Mysterious, massive, magnetic stars

Mysterious, massive, magnetic stars
A cartoon of the two giant stars in the binary system. The polarity of the star's surface magnetic field, north or south, is indicated by red and blue respectively. Yellow lines indicate the magnetic field lines running from the stellar surfaces. Credit: Visualisation courtesy of Volkmar Holzwarth, KIS, Freiburg

A Canadian PhD student has discovered a unique object – two massive stars with magnetic fields in a binary system. Matt Shultz of Queen's University, Ontario, Canada found the system – Epsilon Lupi – and will publish the new result in Monthly Notices of the Royal Astronomical Society.

Around 1/3 of stars in our Galaxy are thought to be in , where two or more stars orbit around a common centre. They are invaluable for astronomers, as watching how they behave lets astronomers measure their mass and connect this with their brightness – a key way in which we understand how stars evolve.

Mr Shultz is a member of the Binarity and Magnetic Interactions in various classes of Stars - BinaMIcS - consortium led by Dr Evelyne Alecian of the University of Grenoble in France. The collaboration is studying the magnetic properties of close binary stars, and Mr Shultz made the discovery using the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii.

Epsilon Lupi is the fourth brightest star system in the southern constellation of Lupus. The pair of stars is about 500 light years away, are both blue in colour, each have between 7 and 8 times the mass of the Sun, and combined together the pair is around 6000 times as luminous as the Sun. Astronomers have known for many years that Epsilon Lupi is a binary system, but had no idea that the two giant stars had magnetic fields.

Shultz comments: "The origin of magnetism amongst is something of a mystery and this discovery may help to shed some light on the question of why any of these stars have magnetic fields."

In cool stars, such as the Sun, magnetic fields are generated by "dynamos" powered by strong convection in the outer layers of the star, where hot material rises, cools and falls back. But there is essentially no convection in the envelopes of massive stars, so there is no support for a magnetic dynamo. Nevertheless, approximately 10% of massive stars have strong magnetic fields.

Two explanations have been proposed for their origin, both variants on the idea of a so-called "fossil" , a field generated at some point in the star's past and then locked into the star's surface.

The first hypothesis is that the magnetic field is generated while the star is being formed; a second is that the magnetic field originates in dynamos driven by the violent mixing of material when two already-formed stars in a close binary merge.

"This discovery allows us to rule out the binary merger scenario," says Mr. Shultz, "However, it doesn't change the basic finding of the BinaMIcS collaboration: fewer than 2% of massive stars in close binaries have magnetic fields, and we still don't know why that is."

The research shows the strengths of the magnetic fields are similar in the two stars, however their magnetic axes are anti-aligned, with the south magnetic pole of one star pointing in approximately the same direction as the north pole of the other. It may even be that the two stars share a single magnetic field.

"We're not sure why yet, but it probably points to something significant about how the stars are interacting with one another", adds Shultz.

The stars are close enough that their magnetospheres are likely to be interacting during the whole of their orbit around each other. This means that their magnetic fields may even act as a giant brake, slowing down the stars. In the long term, the two could be spiralling in towards each other.


Explore further

Magnetospheres: Researcher works to debunk the theory behind massive stars

More information: "Detection of magnetic fields in both B-type components of the ǫ Lupi system: a new constraint on the origin of fossil fields?" arxiv.org/pdf/1507.05084.pdf
Citation: Mysterious, massive, magnetic stars (2015, September 11) retrieved 19 September 2019 from https://phys.org/news/2015-09-mysterious-massive-magnetic-stars.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1671 shares

Feedback to editors

User comments

Sep 11, 2015
this why gentlemen astronomy and astrophysics is mostly conjecture and theories that get proven wrong very often. Like this one, 'large stars should not be magnetic'... but evidence says most are magnetic. Instead of the theory changing they wait for the proof of why it is wrong instead of just switching to the evidence. Which is silly because we are just now gaining the tools to test. It's like saying the sky should be red... but it keeps showing up as blue... and waiting until we can prove why it's blue before changing the thoery to the sky should be blue. Sciences dealing with space are all messed up.

Sep 11, 2015
This comment has been removed by a moderator.

Sep 11, 2015
This comment has been removed by a moderator.

Sep 11, 2015
"First I've heard that a giant ball of plasma doesn't have a magnetic field."

In fact, of course there will in general be a magnetic field in a plasma. However, the issue is the large-scale organization, and hence detectability, of the magnetic field. Think, by analogy, of a bar of iron. Each atom is basically a little magnet: if the magnetic moments of all the atoms in the bar are pointing the same way, you get a bar magnet; but, if they are all pointed a different way, there is no large-scale magnetic field. It is the same with massive stars.

Sep 11, 2015
"Like this one, 'large stars should not be magnetic'... but evidence says most are magnetic."

This is just wrong. Massive stars (above say 1.5 solar masses) transport energy in their outer envelopes via radiation, rather than convection; since the magnetic fields of less massive stars are a consequence of dynamos driven by convection, with no convection there should be no magnetic field. And in fact, as the article states, magnetic fields are detected in ~1/10 massive stars, i.e. the evidence in fact says that most massive stars are NOT magnetic, at least to current limits of detectability, which in fact are precise enough that we can say with high confidence that there are two populations of massive stars, those with strong, organized magnetic fields, and those in which any magnetic fields must be weak and/or disorganized.

Sep 11, 2015
docile: actually, there's very good evidence for a close relationship between rotation and magnetic field strength in low-mass stars, such as the Sun. In massive stars there is no such relationship: this is one of the pieces of evidence that indicates their magnetic fields are not being generated by a convective dynamo, but are rather 'fossil' remnants from a previous period in the star's life.

Sep 11, 2015
This comment has been removed by a moderator.

Sep 11, 2015
Because these stars are programmed in this way. To astonish people and think about the Creator.

if you want to claim something you dont know is god, then be aware that god will be an ever receding pocket of scientific ignorance and will eventually disappear to knowledge-god of the gaps argument

https://www.youtu...kg4hMRjs

this also goes for pseudoscience like docile/ZEPHIR's aw/daw beliefs, which is essentially religion with techno-babble

how do we know that?
http://exphy.uni-...2009.pdf

Sep 11, 2015
This comment has been removed by a moderator.

Sep 11, 2015
This comment has been removed by a moderator.

Sep 11, 2015
The basis of science is documenting the facts and discovering the relationships between them. Not inventing of new reality where visionaries and dreamers can be useful.

Sep 11, 2015

Because these stars are programmed in this way. To astonish people and think about the Creator.


@viko,
Why on earth do you muck up reasonable discussions with your nonsense/non-science on a site? Nobody here will ever be converted to your way of thinking. There are plenty of sites where your delusions are shared. This is not one of them.

Please quit wasting your time and ours trolling this site.

Sep 12, 2015
This is mass culture site. Not scientific cite and the explanation is very simple. In scientific sites you will not find the voting system. Because the true science does not rely on consensus but on facts obtained by observations and experiments. It can not depend on the mood of the anonymous majority, most of whom are not even engaged in science. So you can find constructive dialogs only in the section technology. There is no such thing in others departments. Especially those related to fundamental science. The voting system is a way to influence the opinion of others people who are not who are not secure in their knowledge.

Sep 12, 2015
"The origin of magnetism amongst massive stars is something of a mystery and this discovery may help to shed some light on the question of why any of these stars have magnetic fields."

Because these stars are programmed in this way. To astonish people and think about the Creator.

Viko, I have a question about the omnipotent creator. Could god microwave a burrito so hot that even he couldn't eat it?

Sep 12, 2015
"The origin of magnetism amongst massive stars is something of a mystery and this discovery may help to shed some light on the question of why any of these stars have magnetic fields."

To say the least. As a matter of fact, the origin of any astrophysical magnetic field is a mystery to these dolts. Shown by referring to pseudoscientific mumbo jumbo as "fossil" fields and dynamo created fields. It's obvious a strong background in EM theory is required to solve these mysteries, something which is largely ignored by the theoreticians.

Sep 12, 2015
This comment has been removed by a moderator.

Sep 12, 2015
I am puzzled by the phrase "It may even be that the two stars share a single magnetic field." Put any two magnets near each other and they will essentially share one large field. The only way their statement might make sense is if they postulate that either of the stars on its own would not be able to generate a field, but together they can. I guess I have to read the paper.

Sep 12, 2015
Perhaps they mean 'common envelope' like some really close binaries ?

But I wish the article's editor had been a bit more careful. Saying some stars have *no* magnetic field when they surely meant 'field not strong enough to split spectral lines, so less than whatever Gauss...'

Sep 13, 2015
This comment has been removed by a moderator.

Sep 13, 2015
@mytwocts Monopole magnetosphere


Let's adjust that paper's title for accuracy...

'General-relativistic monopole magnetosphere of neutron stars: a pseudo-scientific discontinuous approach'

Sep 13, 2015
This comment has been removed by a moderator.

Sep 13, 2015
This comment has been removed by a moderator.

Sep 13, 2015
Viko_mx - I wish the voting system on this site was a little different. It would do better with a zero vote possible, or even negative ratings available. Along with a minimum intelligence threshold based on the voting, an ignorant imbecile like you would disappear. Then perhaps the site would be closer to a science site.
It is true however, that a site that is habutually used by delusional psychotics like yourself may not be considered to be a true scientific site. Not because of the voting system, but it's inability to filter out the crackpot delusional psychos like you.

Sep 13, 2015
This comment has been removed by a moderator.

Sep 14, 2015
The contemporary science is based on meritocracy and it depends on consensus heavily
@ZEPHIR
again with the unsubstantiated claims with no evidence? REALLY?
1- SCIENCE is not about consensus
2- just because you believe something to be true doesn't mean it actually is
3- it is not "pluralistic ignorance" to focus science on viable working validated information and skip past pseudoscience
4- your posts are nothing more than validation of why pseudoscience is no different than a religion: belief without evidence, inability to comprehend the scientific method, inability to comprehend the difference between valid evidence and assumption, conjecture or simple "looks like a duck" eu style delusional claims

just because something is talked about doesn't mean it is real, either: see posts here for more details
http://phys.org/n...ics.html


Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
The contemporary science is based on meritocracy

Hint: look at the authors of papers. You will fins that they are NOT the professors but the PhD students and the post docs (i.e those who aren't influential in any kind of institution). It is they who do the science and they aren't organized to any degree that would facilityte 'consensus science'.

The consensus is arrived at by many people independently(!) coming to the same conclusions. And that - for the overwhelming majority of the time - happens only if that conclusion is correct.

You seem to have this strange idea that there is some cabal of a handful of professors sitting somwhere on a high pedestal deigning what is 'correct science' and what is not. Nothing could be further from the truth.

Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
After all, Einstein was an unknown clerk in patent office in the time of publishing of "his" special relativity theory. He wasn't influential professor in his time at all

That was a hundred years ago (and notice that Relativity DID get accepted after it was experimentally validated pretty quickly. Before that it was a nice theory but was hotly debated because it lacked empirical proof)
Yep, this is my usual argument for cold fusion: we have plenty of independent observations

However if you look at these 'indpendent observations' you find that they are anything but independent. Last time Rossi made a demsontration the participants freely admitted that they were not inconrtrol of the preparations nor did replicate the experiments themselves.
http://news.newen...nt-test/

Reading through that interview, how can you say these tests are anything but a giant hoax?

Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
This comment has been removed by a moderator.

Sep 14, 2015
@ 2penny-Skippy. How you are? I am good me. Don't leave off:

franklins
Natello
Teach
Yashi17
TkClick
Terriva
AtlasT
Archea
ValeriaT
Origin


Sep 15, 2015
This comment has been removed by a moderator.

Sep 15, 2015
And what this article is supposed to be about?
@ZEPHIR
well, it proves you can't read, for starters... consensus in science isn't the same as consensus in other stuff... in science, it is the collection of empirical evidence that all (separately done) point to a collective argument... also described in the link you gave
the collective judgment, position, and opinion of the community of scientists in a particular field of study. Consensus implies general agreement, though not necessarily unanimity... Scientific consensus may be invoked in popular or political debate on subjects that are controversial within the public sphere but which may not be controversial within the scientific community, such as evolution or the claimed linkage of MMR vaccinations and autism
this also includes AGW
if you look at the AGW SCIENCE, then there is overwhelming evidence pointing to certain KNOWNs which give the consensus

Sep 15, 2015
What is goal of science is matter of another discussion
@ZEPHIR
this is called conspiracist ideation, and it is because of your religious like belief in a pseudoscience and your fanaticism
BTW I'm also pretty well aware, that the personal attitude of conservative people (like you) tends to be intrinsically dichotomous and self contradicting, if not hypocritical
1- a personal owned PSEUDOSCIENCE site is not valid evidence
2- so... if we prefer science over pseudoscience, and we require evidence of a claim instead of personal conjecture or your religious like belief, then we are the hypocrites and dichotomous/contradicting?

you do know that your above post is nothing more than fanatical ranting diatribe because you've been caught posting lies and religion, not science, right?

it's really simple: you post things with NO evidence based upon your INTERPRETATIONS or OPINION... that makes you another JVK, not a scientist

Sep 15, 2015
This comment has been removed by a moderator.

Sep 15, 2015
Isn't it a common "appeal to authority" fallacy?
@ZEPHIR
no, it is evidence proving your OPINION about a subject is not only WRONG, but that your interpretations are based upon conspiracist ideation and religious belief of pseudoscience
Yep, this is my usual argument for cold fusion: ...plenty of independent observations...impossible to believe, they're all wrong
it is NOT the same:
-you have BELIEF in an observation, not evidence
-there are NO working cf plants pushing out the claimed output
-claims made without evidence or proof are pseudoscience or fraudulent, not "something to look into"
In that case the "consensus" suddenly becomes "very important"
you got it all wrong AGAIN... they're not being accepted because THERE IS NO EVIDENCE... not because of consensus

when you claim 1+1+11, you had better be able to prove it with EVIDENCE
not just a personal belief that putting 1+1 together minus the addition sign is simply like writing 11

Sep 15, 2015
I'm just saying, that the discussion about goal of science doesn't belong in this thread
@ZEPHIR
and discussion of aw/daw or PSEUDOSCIENCE is ok? REALLY?
why is it OK to post YOUR pseudoscience but not try to show you the difference between science and pseudoscience? obviously you didn't read the posting rules, nor did you read the links which describe the difference... so it then is up to others to refute you by any means
You shouldn't see the fanatic religious conspiracy in everything what I say here
it is not about paranoia if i can PROVE it... and it is the actual observation of ALL your posts which prove fanatical religious conspiracist ideation, not just one or two... so yes, it DOES mean it is visible in every post, especially ones where you promote pseudoscience over science with fanatical vigor and no evidence
this would be called a paranoiac delusion
no, my posts are actually: logical deduction based upon overwhelming evidence

Sep 15, 2015
the authors of the paper have never been to another solar system
@bs
WTF????
so, per your own posts, you think all forensic science is crap too?
really?
a forensic investigator can replicate a crime scene giving evidence that is accurate within certain error margins of measurement which are then presented with statistical observations as well as knowledge, which then is evidence proving that in order for A to have occurred, B and C must have been done... this is scientifically valid and it builds upon prior knowledge of validated conclusions (the scientific method)
claiming A doesn't know anything because he hasn't been to B is like saying:
you don't know if the Sun will rise tomorrow because you haven't been to tomorrow
Considering the nature of stars (plasma)
ASTROPHYSICISTS know plasma physics... however engineers do NOT learn astrophysics

leave the eu dogma out of the argument

Sep 15, 2015
I didn't mention "forensic science"
@bsTROLL
i didn't say you did... but it doesn't surprise me you couldn't comprehend that...you said
the authors of the paper have never been to another solar system
this is no different than saying "forensic scientists have never been to the crime scene" (which they don't do), it is also like saying "you weren't there" (a ken ham special- argument from ignorance and god of the gaps argument)
therefore, we can see that you don't believe in the power of forensic science based upon your own commentary above
that is not conjecture or supposition
find me one where
you made the biased conjecture about plasma:
Considering the nature of stars (plasma), saying that 90% do not have a magnetic field is just another fine example of mainstream retardation
where is YOUR evidence supporting this claim?
you can only know what is currently know, BTW
IOW- you posted eu dogma

Sep 15, 2015
OK...what is "claiming 1+1+11" for starters?
@bsTROLL
1- a typo
2- reading comprehension failure at its finest: perhaps you should read it all, eh?
OK...when you write "1 + 1" without the addition sign, what is it actually?
it is a delusional belief that it is eleven, thus it is not substantiated by actual knowledge or facts, but i figured you wouldn't get that... too much math for you, right?
1apple plus 1 apple isn't 11 apples, BTW... just so you know

this is the difference between making unsubstantiated conjecture and actual science with evidence...
perhaps you should read up...(oops... never mind. considering your demonstration above, that was wrong of me! sorry... i didn't know you were challenged & illiterate)

Sep 15, 2015
Where you somehow managed to draw this conclusion about my feelings on forensic sciences from my posts above
@bs
the analogy i used above is perfectly clear to the literate: it is also accurate given your limited description and specific wording
just like your reading fail above re:
Yes, writing a '1' beside another '1'
i noticed that you cherry-picked the data (READING FAIL) because you didn't understand the word problem (MATH FAIL) which then gave you the delusional belief (LITERACY & COMPREHENSION FAIL)
the analogy and descriptions are correct: you cannot derive 11 from adding 1+1 (as stated in the first post)
i had to break it down to Apples plus Apples given your limited grade school education so that you would understand the premise of the post.

i had not realised until now your limitations: shall i continue to break things down to a grade-school level for you?
or can you ask your mom to help?

perhaps you will learn something

Sep 15, 2015
@bsTROLL cont'd
apparently I am biased by volumes of scientific data on the subject
yeah... i am still trying to wade through the huge number of links you gave above supporting your... uhmm... no wait
oops... sorry. that wasn't you! [intentional sarcasm, hyperbole]

my question would actually be: WHY did you intentionally cherry pick the post to distract away from the fact that you had no evidence?
WHY did you use trolling red-herring to focus on your lack of comprehension and literacy skills? (you would think you would hide that, like jvk tries to do)

most important: the problem was simple - how did you misunderstand it? not that far in math yet? or do words confuse the issue?
tried getting examined for dyslexia? it might help you... more than you know

Sep 16, 2015
Nice paper. Wrong conclusions....as usual.

"The Dunning-Kruger is strong with bschott".....

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more