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Space Science

Aging Star System Leaves Strange Death Spiral 79

jamie tips a post at Phil Plait's Bad Astronomy blog about an extremely unusual astronomical phenomenon originating from a binary system about 3000 light years away. Quoting: "The name of this thing is AFGL 3068. It's been known as a bright infrared source for some time, but images just showed it as a dot. This Hubble image using the Advanced Camera for Surveys reveals an intricate, delicate and exceedingly faint spiral pattern. ... Red giants tend to blow a lot of their outer layers into space in an expanding spherical wind; think of it as a super-solar wind. The star surrounds itself with a cloud of this material, essentially enclosing it in a cocoon. In general the material isn't all that thick, but in some of these stars there is an overabundance of carbon in the outer layers which gets carried along in these winds. ... AFGL 3068 is a carbon star and most likely evolved just like this, but with a difference: it's a binary. As the two stars swing around each other, the wind from the carbon star doesn't expand in a sphere. Instead, we see a spiral pattern as the material expands."
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Aging Star System Leaves Strange Death Spiral

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  • by John Hasler ( 414242 ) on Monday September 06, 2010 @07:53PM (#33493332) Homepage

    Given that the only way we could see this amazing sight is it to be "flat" to us in our line of sight...

    It's an amazing coincidence that it is flat on, but we'd still see it if it was at an angle. It' would just look oval rather than round. It would have to be nearly edge-on to be invisible.

    Makes me wonder the same thing about all the planet hunters and exo-planets that we are finding - how many more would we be able to find if it didn't rely on having just the right angle from our vantage point...

    Assuming that the angle is random, the calculation should be straightforward. I'm sure it's been done.

  • by Abcd1234 ( 188840 ) on Monday September 06, 2010 @07:57PM (#33493350) Homepage

    It's a point. What you're seeing is lens flare and glare in the optics. The only star whose surface has been resolved into a disk is Betelgeuse, a red giant star located in Orion.

  • by bunratty ( 545641 ) on Monday September 06, 2010 @07:59PM (#33493356)
    And Sol of course.
  • by MollyB ( 162595 ) on Monday September 06, 2010 @08:04PM (#33493390) Journal

    Makes me wonder the same thing about all the planet hunters and exo-planets that we are finding - how many more would we be able to find if it didn't rely on having just the right angle from our vantage point...

    There are many ways [] to detect extrasolar planets besides the angle of our line of sight. And, as the above poster noted, they've probably got those weird angles figured out, too.

  • by JoshuaZ ( 1134087 ) on Monday September 06, 2010 @09:12PM (#33493806) Homepage

    "The Universe is not only stranger than we imagine it, it's stranger than we can imagine it. (A. Einstein)

    That's a misquote. It is a garbled quote of a line actually due to biologist J. B. S. Haldane who said "My own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose." The line is from "Possible Worlds" (sometimes titled "Possible Worlds and Other Papers.")

  • Basically every picture you see from space gets that treatment. They take pictures using cameras with bandpass filters in the optics, then simply assign 2 or 3 channels to colors if there's more than 1 channel. Unless they want an "as it might be seen" picture they won't use R/G/B filters.
  • links, paper (Score:4, Informative)

    by melikamp ( 631205 ) on Monday September 06, 2010 @11:51PM (#33494686) Homepage Journal

    ESA page with the full-size image. []

    Paper [pdf] [] by Mark Morris, Raghvendra Sahai, Keith Matthews, Judy Cheng, Jessica Lu, Mark Claussen and Carmen Sanchez-Contreras.

    Abstract. [some formatting may be lost] The extreme carbon star, AFGL 3068, is losing mass at a rate in excess of 104 M yr1 , and has so far been detected only in the infrared because it is hidden by a thick dust photosphere having a color temperature of 300K. Using the ACS camera on HST, we have imaged AFGL 3068 with broad-band lters at 0.6 and 0.8 m and nd a thin, apparently continuous spiral arc winding 4 or 5 times around the location of the star, from angular radii of 2 to 10 arcsec. We interpret this as the projection of nested spiral shells such as were predicted to occur when the mass-losing star is a member of a binary system. In this case, the illumination is presumably provided by ambient galactic starlight. Subsequent near-IR observations with the NIRC2 camera on the Keck II telescope using adaptive optics reveal that AFGL 3068 has two components separated by 0.11 arcsec, or 109 AU at a distance of 1 kpc. One very red component is presumably the mass-losing carbon star, while the other component is apparently a much bluer companion. Assuming each component has mass M(M ), and ignoring the projection of the separation vector, we nd the binary period to be 810 M0.5 yrs, strikingly comparable to the 710-yr separation of the shells obtained from the known outow velocity of 14.7 km s1 .

  • by PinkyGigglebrain ( 730753 ) on Tuesday September 07, 2010 @02:19AM (#33495404)
    "There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy." WILLIAM SHAKESPEARE / Hamlet Act 1. Scene V
  • Re:Lens Flare? (Score:2, Informative)

    by Anonymous Coward on Tuesday September 07, 2010 @07:37AM (#33496676)

    They're taking really long exposures with a very sensitive sensor at the limits of engineering. The star on the right many have an incoming photon flux thousands to millions of times of the faint binary system. So the relative exposure means what little diffraction effects from the reflector mountings and aperture builds up a large lens flare over time on the bright stars.

Things equal to nothing else are equal to each other.