Strange, Super-Sized Pulsar Stumps Scientists

by Nancy Atkinson on May 16, 2008

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Astronomers have discovered a fast-spinning, super-sized pulsar in a stretched-out orbit around an apparent Sun-like star. This combination (as well as that many hyphenated words in one sentence) has never seen before, and astronomers are puzzled about how this bizarre system developed. “Our ideas about how the fastest-spinning pulsars are produced do not predict either the kind of orbit or the type of companion star this one has,” said David Champion of the Australia Telescope National Facility. “We have to come up with some new scenarios to explain this weird pair.”

Pulsar J1903+0327, a rotating neutron star, is unusually massive for its type. It spins on its axis 465 times every second, while typical pulsars spin a few times a second. Located nearly 21,000 light-years from Earth, its elongated orbit takes it around its companion star once every 95 days. And the companion star is quite unusual as well: many pulsars pair up with a white dwarf star or another neutron star, but infrared images of the system show a Sun-like star along with the pulsar.

“This combination of properties is unprecedented. Not only does it require us to figure out how this system was produced, but the large mass may help us understand how matter behaves at extremely high densities,” said Scott Ransom of the National Radio Astronomy Observatory.

The image above shows the size and shape of Earth’s orbit around the sun compared to the orbits of Pulsar J1903+0327 and its possible Sun-like companion star. The sizes of the Sun and the possible companion star have been exaggerated by a factor of about 10, while that of the Earth has been exaggerated by a factor of about 1000. The pulsar, with its magnetic field and beams of radiation, is too large by a factor of about 100,000.

This pulsar was first detected in 2006 with the Arecibo radio telescope in Puerto Rico, with subsequent observations by the Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, the Westerbork radio telescope in the Netherlands, and the Gemini North optical telescope in Hawaii.

It’s possible that the pulsar may be part of a triple, not a double, star system. In this case, the pulsar’s 95-day orbit is around a neutron star or white dwarf that’s not been detected yet, not the Sun-like star seen in the infrared image. The Sun-like star would then be in a more-distant orbit around the pulsar and its close companion. But this, too would be highly unusual.

“We’ve found about 50 pulsars in binary systems. We may now have found our first pulsar in a stellar triple system,” Ransom said.

Further studies are underway to get a better understanding of what seems to be a highly unusual system.

“This is a fascinating object that has a lot to teach us about physics. It’s going to be exciting to peel away the mystery of how this thing came to be,” Champion said.

Original News Source: National Radio Astronomy Observatory

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Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

Stephen May 16, 2008 at 12:33 PM

That’s hyphenated-words, obviously.

IToldYa May 16, 2008 at 1:39 PM

Oh no. Not another thing our conventional theories can’t account for!

Richard May 16, 2008 at 2:33 PM

What a place to be! Awesome!

Remember Jack McDevitts “The Hercules Text”: maybe there is no ‘natural’ explanation…

El Sofista - Un púlsar muy extraño May 16, 2008 at 3:58 PM

Los astrónomos han descubierto un púlsar de gran tamaño y veloz rotación en una órbita elongada alrededor de una estrella aparentemente similar al Sol. Esta combinación no había sido observada nunca, y los astrónomos están desconcertados sobre el desarrollo de este extraño sistema. —Nuestras ideas sobre la forma en que se producen los púlsares de rotación más rápida no predicen la clase de órbita [...] Fuentes: Nancy Atkinson para Universe Today y NRAO.

Greg May 16, 2008 at 10:53 PM

I would expect that both the mass of the pulsar and its rapid spin can be easily explained by it stealing mass from the companion star. It’s orbit seems to come close enough for this to happen. This was likely a binary system with the first star dying and forming a pulsar first.

Steve May 17, 2008 at 2:03 AM

Im inclined to agree with Greg. It does seem highly plausible that this pulsar is stealing mass from the sun like star.

However, what doesn’t make sense to me is this apparent orbit, as a binary system that is. All binary systems we know of have a common centre of gravity somewhere…ie earth / moon, Pluto / Charon and many other bodies.

Also, it occurs to me that, the variation of the orbits seems rather odd, as the objects don’t orbit around each other, which definately does seem to be a triple system.

Im inclined to form an opinion that the pulsar is in orbit around a neutron star in a fairly stable orbit, and the varying fluctuation of the pulsars position in orbit relative to the main sequence star will explain its comet like orbit.

Henry Wysmulek May 17, 2008 at 9:36 AM

Could be they are stumped because their unfounded theories are based on unfounded theories,on unfounded theories.

Since when do we know what is or is not possible, or normal????????????????????

Human arrogance once again.

David May 17, 2008 at 3:47 PM

I would hardly consider most of these theories unfounded, some have been hundreds of years in the making.

Mek May 17, 2008 at 4:17 PM

Henry Wysmulek,

Bah! What you condemn as human arrogance, I would praise as a human curiosity of the most beautiful sort. Hell, to call it just that would be an understatement; I would call it a melding of our natural curiosities and our imagination, tempered to know nature, to discover the world and to maybe, just maybe, to understand the universe.

Are we arrogant on stand on this little speck of cosmic dust, and to claim that we might understand the universe? Would you also call ancient astronomers arrogant for noticing the planets wander around the stars, and to speculate on their true nature? To try to understand how they might move? On what they speculated on so widely, their descendants now send probes to on a regular basis. Maybe in the future our own descendants will have powerful enough telescopes to proves wrong and right, as we did in the case of ancient astronomers.

You call humans arrogant because they admit to be at fault when nature prove them so. I say call them arrogant only when they start ignoring nature altogether. :/

dmedici May 17, 2008 at 7:11 PM

I’m still thinking of the 465 times per second rotation. How are we measuring that?

Astrofiend May 18, 2008 at 3:21 AM

Henry Wysmulek Says:
May 17th, 2008 at 9:36 am

“Blah blah blah…”

I would say that posting ignorant comments on something that you obviously know very little about is fairly typical of human arrogance.

Refining admittedly imperfect scientific theories about the very nature of the remarkable universe in which we live would be considered the height of human ingenuity and the pinnacle of human achievement in my opinion. That is actually the way science works you know…

Astrofiend May 18, 2008 at 3:29 AM

# dmedici Says:
May 17th, 2008 at 7:11 pm

“I’m still thinking of the 465 times per second rotation. How are we measuring that?”

Rotation speed is most simply determined by measuring the time between spikes in the received radio flux from the object. Rapid timescale photometry of the source at visual wavelengths and observations at other wavelengths can also be used.

dmedici May 18, 2008 at 11:28 AM

Astrofiend,

Thanks for the reply; I did some more reading on these enigmatic objects. Fascinating.

Astrofiend May 18, 2008 at 5:14 PM

No problem!

Debi-Lee Wilkinson May 19, 2008 at 12:54 PM

But it is an assumption that the rate of pulsation is only determined by the rate of rotation. This is an example of what annoys Henry. We can’t see it, so how can we say how it operates. We produce theories that give a coherent set of answers for enough cases that the theory becomes plausible. But, just like in the game of Simon Says, we start thinking we have the answers.

What bothers me more about this, is that if the pulsar is more massive than the star (the article doesn’t say that but seems likely) why are we saying the pulsar is orbiting the visible star? As Steve pointed out, one doesn’t orbit the other, the orbit each other. Again, sloppy verbiage due to our human experience that our solar system is dominated by co-orbiting bodies where one is much larger than the other.

Emission Nebula May 19, 2008 at 2:57 PM

Is it possible that a stellar mass black hole could be located somewhere towards where the two stars paths cross?

Astrofiend May 19, 2008 at 7:04 PM

Debi-Lee Wilkinson Says:
May 19th, 2008 at 12:54 pm

“But it is an assumption that the rate of pulsation is only determined by the rate of rotation. This is an example of what annoys Henry. We can’t see it, so how can we say how it operates. We produce theories that give a coherent set of answers for enough cases that the theory becomes plausible. But, just like in the game of Simon Says, we start thinking we have the answers. ”

Yes, when stating that the pulsar rotates 465 times per second, it is implied that this only holds if the theory on which the deduction is based is true. The reason it is stated as fact is that the sheer volume of observations consistent with this rather simple aspect of the interpretation of such objects is mind boggling. What’s more, if we are to going to decouple the rotation rate of the object from the frequency of observed pulses, you have to come up with another satisfactory explanation of the phenomenon that is consistent with the literally millions of basic observations that essentially fit perfectly with the current paradigm.

No scientist on Earth actually believes that we understand Pulsars well, but the rotation rate, this most basic of theoretical deductions is so well supported by both the evidence and lack of contradictory evidence that we talk of it as fact until there is some sort of evidence or observation to suggest it is wrong.

“What bothers me more about this, is that if the pulsar is more massive than the star (the article doesn’t say that but seems likely) why are we saying the pulsar is orbiting the visible star? As Steve pointed out, one doesn’t orbit the other, the orbit each other. Again, sloppy verbiage due to our human experience that our solar system is dominated by co-orbiting bodies where one is much larger than the other.”

Look, it may be sloppy verbiage or warped human-centric thinking or whatever your point is, but it’s not that hard to understand what is implied or meant by the phrase you refer to. This is a popular science website – if it were to be absolutely precise with the language, then it would read more like a scientific journal which nobody but scientists would read because the language is so cumbersome and specialised.

Instead of saying ‘the pulsar is in orbit around a star’, we could say the more precise and accurate ‘the pulsar and star are both moving along spacetime geodesics that wrap around each other due to the warpage of spacetime caused by masses of each body in question’, but even this language is fairly non-technical and imprecise when it comes to physics.

This site simply reports on and summarises the latest scientific findings. If you want the whole shebang and detailed scientific arguments, go and look up the corresponding articles in the scientific journals!

Ricky Diaz May 22, 2008 at 2:25 AM

I’m kind of confused about “Super-Sized Pulsar”. It doesn’t say anywhere the pulsar is unusually large. Do they just mean massive, like a magnetar? I also heard about the discovery of a triple planetary system around a pulsar. Wouldn’t the supernova be too powerful for matter to gather up and form planets less than a billion miles away? And wouldn’t the supernova destroy any planet orbiting it? Although the neutron star should pull their atmosphere, leaving only their cores, we can’t tell. There is also a planet around a neutron star white dwarf binary. And a planet around a triple star system, a quadruple star system, one around a brown dwarf, 1 that goes around it’s star is 29 hours, 1 1.7x Jupiter’s diameter, but still less massive, the possibility of a planet around Alpha Centauri, 1 with winds blowing 6,000 mph 6 times faster than Neptune’s winds, 2 rocky planets around Gliese 876, 1 at the outer edge of the habitable zone and 1.5x Earth’s diameter, a gas planet 12 times Jupiter’s mass and at least 2x Jupiter’s diameter, a gas planet 2.5x Earth’s diameter. I made an image with gas planets of those sizes. The planet twice Jupiter’s diameter sure is way bigger than the gas planet 2.5x Earth’s diameter. And larger than some known red dwarf stars. If a single stellar nebula can condense and form 2 stars, a minimum mass red dwarf can have a planet larger than the star itself. Since many exoplanets have eccentric orbits and many have spiral in closer to the star, there are definitely binary gas planets. Similar to Pluto and Charon, but of course on a larger scale. If Jupiter’s moon Europa has an ocean beneath the ice created by heat from the moon being stretched and squeezed due to it’s non-circular orbit around Jupiter, and the heat from the Sun as a red giant won’t be hot enough to melt Europa’s ice, life in Europa if exists might last forever, unless another star passes too close, or if a massive star close enough goes supernova and the radiation reaches Europa. Possibly like Betelgeuse. I wish a space team would send a very large, very bright light maybe just a few miles in the sky orbiting Earth inside a crystal shaped gizmo so it would look like a twinkling red giant star less than 1 light year away.

Well I was just sharing additional interesting facts and ideas, because I knew people come here to read other’s comments.

TROY June 25, 2008 at 10:26 AM

“Instead of saying ‘the pulsar is in orbit around a star’, we could say the more precise and accurate ‘the pulsar and star are both moving along spacetime geodesics that wrap around each other due to the warpage of spacetime caused by masses of each body in question’, but even this language is fairly non-technical and imprecise when it comes to physics.”

WHAT?

Your point exactly!!
The fact is that theories are created, proven and disproved all the time. That’s where the facination comes from.

465 RPS is unfathomable to me yet until disproven that’s the facts.

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