Two Massive Stars with Magnetic Fields Discovered in Binary System Epsilon Lupi

Astronomers Discover Two Massive Stars with Magnetic Fields in a Binary System

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.

In a newly published study, astronomers reveal that the two giant stars in binary system Epsilon Lupi have magnetic fields.

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 published the new result in Monthly Notices of the Royal Astronomical Society.

Around 1/3 of stars in our Galaxy are thought to be in binary systems, 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 color, 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 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.”

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” magnetic field, 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 stars could be spiraling in towards each other.

PDF Copy of the Study: Detection of magnetic fields in both B-type components of the ε Lupi system: a new constraint on the origin of fossil fields?

Source: Royal Astronomical Society

7 Comments on "Two Massive Stars with Magnetic Fields Discovered in Binary System Epsilon Lupi"

  1. How close are they?

  2. “The origin of magnetic fields around stars is a mystery….”.
    No it is not. It’s just that the establishment refuses to acknowledge that gravity-based standard model is incorrect.
    The origin of all magnetic fields is an electric current. Period. It has been established that there are electric currents flowing into and away from stars (Birkeland currents). This includes our sun. Look at the Aurora Borealis if you want proof.
    There are also documented intergalactic flows of electric current as has been recently documented by radio telescope data. It seems these “filaments” stretch over light years at exactly the same diameter and are the source of star formation.
    Even more important are the massive magnetic fields surrounding the galaxies and “black holes” which should more properly be called galactic centers. These bodies actually appear to be rapidly rotating, super dense plasmoids. The would eliminate the need for dark matter, dark energy,neutron stars and black holes…all theoretical concepts that defy confirmation and defy the known laws of physics and chemistry. Besides, there is nothing black about a “black hole”, all sorts of powerful electromagnetic radiation escapes from these bodies continuously. The fact that plasma jets have been documented escaping black holes recently is the coupe de gras for the gravitational theory of black holes.
    All of the science fiction fantasies known as the standard model are being contradicted and disproven by the advances in radio astronomy. Without the latest data we would still be living in a world based on ideas developed in the 17th century.
    Even gravity seems to be a result of electrical interactions between charge separations that occur within all matter. All matter, being composed of electrons at some level, is electrical in nature. It makes common sense that all interactions be governed by electromagnetic principles. This concept will soon result in the “GUT” or grand unified theory of everything that has thus far eluded mankind.

  3. I don’t know how much is electromagnetic with gravity contributing to “the dark Matter” ?

    did or didn’t … that thing been considered, and magnetism …

  4. and there is a way more to the story of the Universe after all….

    The Sun is moving and all planets are traveling along, and the whole our galaxy is spinning and all of the galaxies are moving and so on….

    Yeah, the dark mater, one day you will understand at the very end!

  5. and one non rhetorical… one

    If one know the mass and the size of the black whole. Could one then figure out the dimension of the space time from those things?

  6. a one more question… if let’s say dark mater exists could it have negative gravity and that might be the reason why wee don’t see the dark mater particles.

  7. One more thing… well, few of them though…

    I just heard that the temperature of the body will influence the gravity, and now I ask my self about the speed too.

    Yeah, the barycentre is the place all planets and sun are revolving around… hmh the GEOMETRY of the space time, yeah very strange geometry that can be affected by strange things…

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