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Fastest (and Most Compact) Stellar Spinner Confirmed

Posted by Soulskill on from the getting-dizzy-now dept.

gregg writes "HM Cancri has been confirmed as a binary system of two white dwarfs orbiting each other so closely that they complete one orbit every 5.4 minutes; they are separated by a mere 8 Earth diameters. 'These are the burnt-out cinders of stars such as our Sun, and contain a highly condensed form of helium, carbon and oxygen. The two white dwarfs in HM Cancri are so close together that mass is flowing from one star to the other. HM Cancri was first noticed as an X-ray source in 1999, showing a 5.4 minutes periodicity, but for a long time it has remained unclear whether this period also indicated the actual orbital period of the system. It was so short that astronomers were reluctant to accept the possibility without solid proof. '"

47 comments

  1. Mass flow is common. by John+Hasler · · Score: 1

    > The two white dwarfs in HM Cancri are so close together that mass is flowing
    > from one star to the other.

    Not a unique feature of this pair. This is common in pairs that are much farther apart.

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    1. Re:Mass flow is common. by AstroMatt · · Score: 5, Informative

      It happens in binary main sequence stars. This is only one of 2 binary white dwarf systems that have direct impact accretion (the other is named V407 Vul). Usually the accretion stream misses the primary star, and forms an accretion disk. In these systems, the accretion stream slams into the the accreting white dwarf at a velocity of about 1% the speed of light, btw!

    2. Re:Mass flow is common. by FatdogHaiku · · Score: 4, Interesting

      Does this mean that at some point one of them could lose so much mass that there will no longer be a stable pair? I have this vision of one of them suddenly shooting off at a tangent at a horrendous velocity like some cosmic bowling ball.

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    3. Re:Mass flow is common. by frieko · · Score: 3, Informative

      Like this?

    4. Re:Mass flow is common. by FatdogHaiku · · Score: 1

      Yup, kinda what I was thinking. Wouldn't want to be sitting at the telescope and notice a blue shifted star getting bigger and bigger...
      Thanks for the link.

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    5. Re:Mass flow is common. by LynnwoodRooster · · Score: 1

      It's easy to observe, too! Mass tends to flow from my mouth to my ass, where some continues on outside the body and the rest seems to accumulate...

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    6. Re:Mass flow is common. by MartinSchou · · Score: 1

      You have a really weird way of playing bowling. Now, if you had gone with hammer throw, you would have had a much better analogy.

    7. Re:Mass flow is common. by FatdogHaiku · · Score: 1

      A former girlfriend almost kneecapped me one time while I was teaching her to bowl, no joke. She let go of the ball on the back swing and I had to jump to clear it.

      I don't try to teach anyone to bowl anymore.

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    8. Re:Mass flow is common. by Jenming · · Score: 2, Insightful

      If you make a closed box around the two white dwarfs and move mass from one to the other you will see that the center of gravity does not change and so I would not think anything would go flying off. Rather both bodies would just move toward the center of gravity while the larger one got larger and the smaller got smaller. If they collided with some force stuff could be thrown away from the collision, but no escape velocity could be reached without another force being involved.

      --
      Morpheus, God of Dreams.
  2. I wonder what it would look like by Anonymous Coward · · Score: 0

    I wonder what it would look like standing on the surface of one, watching the other pass overhead at supersonic speeds?

    If such a thing were possible, of course. I know that they're both collapsed stars that still must have uninhabitable temperature conditions, and they're both gaseous bodies that don't really have defined surfaces. But still, it's gotta look awesome.

    1. Re:I wonder what it would look like by sirrunsalot · · Score: 4, Funny

      Supersonic? Keep in mind that in space, no one can hear you... oh, nevermind.

    2. Re:I wonder what it would look like by S.O.B. · · Score: 1

      If you can't hear in space why is there a whooosh when the Enterprise goes by?

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  3. Oh my God... by santax · · Score: 1

    I would be so pissed if my alarmclock went ringing every 5.4 minutes! I say we nuke 'em just to be sure we will never build a colony there!

    1. Re:Oh my God... by Rich0 · · Score: 1

      Well, I don't know what the masses of these stars are, but if they're high enough they'll eventually "nuke" themselves. When one star gains enough mass - either by pulling it out of the other or from the eventual collision when their orbits collapse - if that star has sufficient mass it will trigger a supernova as the core collapses into a black hole.

    2. Re:Oh my God... by santax · · Score: 1

      I am sorry my friend, although you are probably right, 'probably' just isn't good enough with my alarm-clock ringing every 5.4 minutes. We need guarantees!

    3. Re:Oh my God... by Anonymous Coward · · Score: 0

      You could throw every nuke on Earth at this simultaneously and you wouldn't even notice the blip on the radiation output.

      You'll need to find something MUCH bigger.

    4. Re:Oh my God... by mrtommyb · · Score: 5, Informative

      The total mass is almost certainly less than 1.4 time the mass of the sun and therefore does not have enough total mass to create supernova and a neutron star (its nowhere near massive enough to form a black hole).

    5. Re:Oh my God... by GNUALMAFUERTE · · Score: 1

      Ok, let's throw Oprah into the star.

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    6. Re:Oh my God... by SPickett · · Score: 1

      From the last line of the article neither of us read:
      "It is thought that the white dwarf pair are reaching the end of their frenzied dance. As more gravitational waves are generated, energy is lost from the system, making them spiral closer together until they collide, possibly exploding as a type 1a supernova."

    7. Re:Oh my God... by Anonymous Coward · · Score: 0

      Even if we're orbiting? But I was so sure!

  4. Proof? by Mycroft-X · · Score: 3, Funny

    It was so short that astronomers were reluctant to accept the possibility without solid proof.

    What about very hot, plasmatic proof?

    1. Re:Proof? by lvincentl · · Score: 1

      What about very hot, plasmatic proof?

      Meh, I never thought that Wendy Williams was that hot.

  5. Re:Another discovery by goldaryn · · Score: 5, Funny

    i found red lint in my navel. BUT MY SWEATER IS BLUE!?!??!?!! WHY?????

    Perhaps you have a binary star system in your navel, and the Doppler effect is inducing velocity variations in the spectral lines in the light between the lint and your eyes.

    Is the lint changing colour every 5.4 minutes? Is your head 16,000 light years away from your head?

    I think we should send in the University of Warwick to investigate.

  6. Tidal bulges by Frequency+Domain · · Score: 3, Insightful

    The artist's rendition shows two spherical bodies, but there's no way that can be correct. At the orbital velocities involved these things must have tidal bulges that make Kevin Smith look positively svelte!

    1. Re:Tidal bulges by wizardforce · · Score: 1

      You have to remember that a white dwarf's gravity is truly enormous and that even at the orbital velocities these dwarfs are orbiting each other, they should still be mostly spherical. At least spherical enough that an artists' rendition shouldn't be too inaccurate.

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    2. Re:Tidal bulges by mrtommyb · · Score: 4, Interesting

      Actually the less massive donor star is really quite non-spherical. The shape will will what is known as a Roche Lobe, this is a 3D teardrop shape. The donor will also be several time larger than the more massive primary star.

    3. Re:Tidal bulges by AstroMatt · · Score: 5, Informative

      The mass losing star is somewhat teardrop shaped, with the point pointing towards the other star - that's where mass flows through. It's a 3D analog of a spring-fed lake in a valley overflowing a saddle pass and flowing into the next valley. The mass flow in this system is likely helium mostly, and the rate is equivalent to about 100,000 Nimitz-class aircraft carriers per second. The impact velocity is about 1% the speed of light.

    4. Re:Tidal bulges by bcrowell · · Score: 4, Informative

      The artist's rendition shows two spherical bodies, but there's no way that can be correct. At the orbital velocities involved these things must have tidal bulges that make Kevin Smith look positively svelte!

      You're right, the artist's conception is messed up. Here is the scientific paper. Figure 3 on p. 4 has a realistic diagram, showing one star completely filling its Roche lobe.

      Anyway, this is cool because this system is much closer and higher in frequency than the classic Hulse-Taylor binary pulsar. That means that it's radiating gravitational waves at a much higher rate.

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    5. Re:Tidal bulges by Frequency+Domain · · Score: 1

      Here is the scientific paper. Figure 3 on p. 4 has a realistic diagram, showing one star completely filling its Roche lobe.

      Way cool! Thanks for the link.

    6. Re:Tidal bulges by bami · · Score: 1

      How much is that in Volkswagen Beetle terms?

    7. Re:Tidal bulges by Rogerborg · · Score: 1

      The mass losing star is somewhat teardrop shaped

      Pics or it didn't happen. Or more prosaically, "I believe that" would be appropriate here.

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    8. Re:Tidal bulges by Anonymous Coward · · Score: 0

      Well, that's cool, but it's still just the scientists conception. We won't really know what its like until we get a closer look. Can we use it to detect gravitational waves though? I thought they were still beyond our observation skills as well.

    9. Re:Tidal bulges by AstroMatt · · Score: 1

      Stars are a bit far to resolve, and these stars are about the size of the earth, so no pictures of this will be available in your lifetime. But assuming you accept that we understand physics and can simulate what things look like, please visit http://astro.fit.edu/wood/visualizations.html. This is not new. It's called the Roche lobe and is simply an equipotential surface. Here's an image from a textbook http://physics.uoregon.edu/~jimbrau/BrauImNew/Chap20/FG20_22.jpg

  7. The best use for this by Takeel · · Score: 2, Funny

    The best use for this is obviously to install it on the wheels of a stellar El Dorado.

  8. corrected by anupokritos · · Score: 0, Offtopic

    Er, Fastest (and Most Compact) (that we currently know of) Stellar Spinner Confirmed.

  9. Isn't that Jenna Haze? by Anonymous Coward · · Score: 0

    Hmm, I thought the most compact and sexiest spinner is Jenna Haze. Who is this new porn spinner? http://en.wikipedia.org/wiki/Spinner_(porn_industry)

  10. Re:Another discovery by Sponge+Bath · · Score: 3, Funny

    Is your head 16,000 light years away from your head?

    Woah. You just blew my mind.

  11. Starships have sensors. by tepples · · Score: 2, Funny

    If you can't hear in space why is there a whooosh when the Enterprise goes by?

    Spacecraft have sensors that pick up electromagnetic signatures of nearby spacecraft. These are connected to computers that transform sensor data into visualizations (graphics) and auralizations (sound effects) for the bridge crew. What you are hearing is a sound effect that represents a passing starship.

    1. Re:Starships have sensors. by struppi · · Score: 1

      The comet was only a few kilometres across and plowed into the solid planet at over a dozen kilometres per second, so it pulverised itself out of existence in less than a second, hurling black-grey-brown-red-white spurts of material off from the impact point in arcs, most of them directed in the direction of impact, themselves leaving lines of smaller impacts around the edge of the planet, while a visible black ripple spread out from the origin. FOOOOOOOOOOOOOOOOOOOOOM was how Jex and Yuo's onboard videoaudio sound effect generator chose to interpret this.

      The last but one question by Sam Hughes

  12. Is that you Mr. Berman? by tjstork · · Score: 1

    Spacecraft have sensors that pick up electromagnetic signatures of nearby spacecraft.

    Put in a couple of relays in there, add some emitters with a dash of a core breach, and you got yourself a TNG Trek writer!

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    1. Re:Is that you Mr. Berman? by troll8901 · · Score: 1

      Put in a couple of relays in there, add some emitters with a dash of a core breach, and you got yourself a TNG Trek writer!

      Put in a couple of bad guys in there, add some gratuitous sex scenes, and you got yourself a best-seller!

    2. Re:Is that you Mr. Berman? by tjstork · · Score: 1

      Put in a couple of bad guys in there, add some gratuitous sex scenes, and you got yourself a best-seller!

      Sounds like a good plan!

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  13. There's a small, athletic porn star in space? by SlappyBastard · · Score: 1

    And I don't care how good she is, "stellar" is just too strong of an adjective.

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  14. Youtube video by MillionthMonkey · · Score: 1

    This is a video of two combining neutron stars, not white dwarves, so you'll have to suspend disbelief.

  15. Re:Another discovery by Anonymous Coward · · Score: 0

    Terribly offtopic, but research was done into this, and the lint also comes from your underwear. Seriously.