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Space Science

New Class of Galaxy Discovered 104

Posted by Soulskill
from the give-peas-a-chance dept.
fructose sends along this excerpt from Space Daily: "A team of astronomers has discovered a group of rare galaxies called the 'Green Peas' with the help of citizen scientists working through an online project called Galaxy Zoo. The finding could lend unique insights into how galaxies form stars in the early universe. ... Of the 1 million galaxies in Galaxy Zoo's image bank, only about 250 are in the new 'Green Pea' type. Galaxy Zoo is claiming this as a success of the 'citizen scientist' effort that they spearheaded. ... The galaxies, which are between 1.5 billion and 5 billion light years away, are 10 times smaller than our own Milky Way galaxy and 100 times less massive. But surprisingly, given their small size, they are forming stars 10 times faster than the Milky Way. 'They're growing at an incredible rate,' said Kevin Schawinski, a postdoctoral associate at Yale and one of Galaxy Zoo's founders. 'These galaxies would have been normal in the early universe, but we just don't see such active galaxies today. Understanding the Green Peas may tell us something about how stars were formed in the early universe and how galaxies evolve.'"
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New Class of Galaxy Discovered

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  • 5 billion light years away means that we're seeing them how they were 5 billion years ago. Do they even exist in their current form or did they merge into larger galaxies to take advantage of synergies?

  • by Shrike82 (1471633) on Wednesday July 29, 2009 @08:23AM (#28865193)
    See this is what happens when all the good names are already taken - a serious project aimed at cataloging distant galaxies is forced to call itself "Galaxy Zoo".
    • Re: (Score:3, Interesting)

      by Vectronic (1221470)

      Indeed, and they also missed out on calling these Galactica, instead of Green Peas

    • See this is what happens when all the good names are already taken - a serious project aimed at cataloging distant galaxies is forced to call itself "Galaxy Zoo".

      Isn't this also how early morning rush hour radio shows get named?

  • There is a theory that the expansion of a galaxy "tears" spacetime and creates an energy differential. The energy differential then, as special relativity predicts, transmutes to matter thus creating the matter to form stars.

    Given that it is the expansion of the galaxy that causes the creation of matter, it makes sense that smaller, more active galaxies would be able to create new stars.

    • Re: (Score:3, Informative)

      Given that it is the expansion of the galaxy that causes the creation of matter, it makes sense that smaller, more active galaxies would be able to create new stars.

      I don't know how to respond to this statement. This is the tenth time I've written something before erasing it to start over to sound less inflammatory. I guess I'd just like a citation to this "theory" of the diffusion of matter begetting more matter. It sounds like some whacked-out solid state universe theory.

    • by wanerious (712877)
      This doesn't make any sense. Galaxies don't expand, the Universe does. What does 'tearing' spacetime mean? How does this create (or use?) energy? We don't need anything so esoteric --- it is fairly well-accepted now that the early galaxies were probably small and vigorous centers of star formation, later merging into the flavors we see closer around us today. We are now seeing confirmation of these ideas.
  • My pre-teen kids LOVE Galaxy Zoo...they feel they're really helping push out the boundaries of knowledge, and I get lots of teachable moments.

  • by kimvette (919543) on Wednesday July 29, 2009 @08:29AM (#28865291) Homepage Journal

    "10 times smaller than our own Milky Way galaxy and 100 times less massive"

    10 times smaller?
    100 times less massive?

    Isn't it 1/10 the size and 1/100 the mass?

    In order to be "10 times smaller than $foo" or "100 times less massive than $foo" doesn't there need to be another point of reference?

    I know I'm picking nits, but this is slashdot. People should know better. This bugs me like less vs. fewer, there/their/they're, your/you're, and so forth. I understand it is simply a colloquialism arising from poor grammar among the masses, but in the case of a scientific article, poor writing makes it more difficult to take the writer seriously.

    • by FudRucker (866063)
      that struck me as odd too, seems like the stars would be much more congested in to a smaller area (if my fuzzy math is even near the ballpark)
      • by rnelsonee (98732)

        No - 10x smaller means 100x less area to deal with.

        If you had a brother that was twice as tall as you, but all body parts were proportional to you, his shadow's area would be 4x yours (length x width) and he would weigh 8x as much as you do (l x w x h).

        So galaxies are typically sized up by their diameter. If it's 1/10th the diameter, and area = Pi*r^2, then we're at 1/100th of the area, so the stars can be distributed just like ours and it all works out (although, the other galaxy would have to be the same

    • by BitZtream (692029)

      I think the problem here is your reading comphrehension skills, from the line you quoted it should be pretty clear that the point of reference is the Milky Way.

      • by albedoa (1529275)
        Are you being ironic? His reading comprehension is fine. You cannot be "x times smaller" than something because it is relative to a ceiling of infinity. Draw it on a number line: 10 is ten times larger than 1 because it is ten times farther from 0 on a number line. 1 is ten times less than x because it is ten times farther from y on a number line. Go on, fill in the values for x and y.
        • by quadrox (1174915)

          And there you have it, the other reference point is quite obviously 0. I don't quite see what the fuss is all about?

          • by ScentCone (795499)
            I don't quite see what the fuss is all about?

            The fuss is over the fact that saying something is 10 times smaller than something else means that the thing you're comparing it to is, itself, already considered small. But compared to what? It's meaningless. Shorter, and more accurate to simply say "it's a tenth the size."

            People drag out the "ten times..." type stuff when they're trying to sensationalize something that's... not sensational. It's like some sophomore trying to add words to an essay that ha
            • by quadrox (1174915)

              I'm sorry, but when I say that my house is smaller than yours, I do in no way imply that your OR my house is small in absolute terms. It just means that one is less big than the other.

              Now, just saying it is smaller than the other is relatively vague, because we do not know how great the difference actually is. Adding that information does in absolutely no way change the point in my first paragraph. Saying something is smaller than something else does NOT imply that one or both items are small themselves.

              • by quadrox (1174915)

                Just to make absolute sure you understand my point (I do understand how you arrive at your wrong assumption btw), imagine there are three well established categories of some item: small, medium, large.

                Now when comparing two items in the medium category, how do you relate their relative size to each other? Exactly, you say one of them is smaller/bigger than the other. But that does NOT imply that the items are in the small/big category, it just points out the difference in size.

                And when qualifying the stamen

        • by Chris Burke (6130) on Wednesday July 29, 2009 @10:56AM (#28867607) Homepage

          Draw it on a number line: 10 is ten times larger than 1 because it is ten times farther from 0 on a number line. 1 is ten times less than x because it is ten times farther from y on a number line. Go on, fill in the values for x and y.

          No, 10 is ten times larger than 1 because the ratio of their sizes is 10:1.

          1 is ten times smaller than 10 because the ratio of their sizes is 1:10.

          It's about relative not absolute size difference. That's why they say "10 times smaller" rather than "10 units smaller". "Times" is your clue that you're dealing with multiplication, i.e. ratios.

          The language is perfectly clear, correct, and unambiguous. No, your reading comprehension is not fine.

          • Draw it on a number line: 10 is ten times larger than 1 because it is ten times farther from 0 on a number line. 1 is ten times less than x because it is ten times farther from y on a number line. Go on, fill in the values for x and y.

            No, 10 is ten times larger than 1 because the ratio of their sizes is 10:1.

            1 is ten times smaller than 10 because the ratio of their sizes is 1:10.

            The basic problem is a lot clearer if you're dealing in percentages:

            3 is 50% larger than 2. (3 = 2 + 50% of 2)
            2 is 33% smaller than 3. (2 = 3 - 33% of 3)

            2 is not generally considered 50% smaller than 3, even though 3/2=1.5. Nor is it considered 66% smaller than 3, even though 2/3=66.6%.

            The basic ambiguity when talking about relative factors that separate two quantities (particularly when attached to concepts like smaller, colder, etc. - inverse scales) is what your baseline of measurement is. Largeness

            • by Chris Burke (6130)

              The basic problem is a lot clearer if you're dealing in percentages:

              3 is 50% larger than 2. (3 = 2 + 50% of 2)
              2 is 33% smaller than 3. (2 = 3 - 33% of 3)

              2 is not generally considered 50% smaller than 3, even though 3/2=1.5. Nor is it considered 66% smaller than 3, even though 2/3=66.6%.

              And the solution is clear when you look at the terms you are using versus the analogous terminology in summary. You are using additive terminology, the summary uses multiplicative terminology. See:

              3 is 50% larger than 2. 3

              • by Tetsujin (103070)

                Or you could stop using pedantry as an excuse to not understand the correct usage of language (because that's the opposite of pedantry), and realize that "X times smaller" means "1/X times larger".

                The fact that I am being pedantic does not imply that I am wrong. Inverse measures simply don't work well as the basis for quantitative comparisons. Not given our long-standing decision to measure the size of things linearly, as opposed to using the inverse scale.

                "times larger" means the same thing whether you take the two words separately or together. "times smaller" does not.

              • 3 is 50% larger than 2. 3 is 150% of 2. 3 is 1.5 times larger than 2.

                Except that, well, its not. 3 is 1.5 times as large as 2, it is not 1.5 times larger than 2. (Just as 2 is one time as large as 2, not one time larger than 2.)

                "X times larger" is frequently sloppily used where "X times as large" is correct, and "X times smaller" used, even more sloppily, by reverse analogy to the abuse of "times larger" when "1/X times as large" would be correct.

                "X times larger" is also sometimes used, arguably more correc

            • by Fluffeh (1273756)

              3 is 50% larger than 2. (3 = 2 + 50% of 2)
              2 is 33% smaller than 3. (2 = 3 - 33% of 3)

              2 is not generally considered 50% smaller than 3, even though 3/2=1.5. Nor is it considered 66% smaller than 3, even though 2/3=66.6%.

              Good god, do you have any idea of how many times I have tried to explain this simple concept to the senior business managers that read the analytical reports that I and my department publish within my company? It's just a joke that so many people who are in senior roles within a business simply don't understand simple mathematical concepts.

          • by HTH NE1 (675604)

            The language is perfectly clear, correct, and unambiguous.

            It's oxymoronic to say "times smaller".

            You're suggesting implied reciprocals where "x times smaller than" means "one xth the size of" when the latter is perfectly fine English just to avoid explicitly mentioning a fraction.

            It makes as much sense as talking about the "near distant" future.

            • by Chris Burke (6130) on Wednesday July 29, 2009 @12:46PM (#28869853) Homepage

              It's oxymoronic to say "times smaller".

              No it isn't, unless you think you can only multiply by values larger than one, which would simply be moronic.

              You're suggesting implied reciprocals means "one xth the size of" when the latter is perfectly fine English just to avoid explicitly mentioning a fraction.

              Yes, heaven forbid there be multiple correct and clear ways to say the same thing in English. *eyeroll* In some cases it flows better than using fractions.

              It makes as much sense as talking about the "near distant" future.

              No, it makes perfect sense as long as you understand what it means. Which isn't complicated, and now you know it, so there should be no further issues with this perfectly clear and unambiguous language.

              • by HTH NE1 (675604)

                It's oxymoronic to say "times smaller".

                No it isn't, unless you think you can only multiply by values larger than one, which would simply be moronic.

                Then why isn't it "1/10 times smaller"? Why does no one use a fraction with the word "times" colloquially? It would better as "10 divisions smaller than x", as in "if you divided x into ten equally sized partitions, it would be the size of one of them," if not "1/10 the size of x".

                In an idiom employing redundancy, by using the antonym of only one of the words therein you create an oxymoron.

                Not that oxymorons are universally wrong.

                • by Chris Burke (6130)

                  Then why isn't it "1/10 times smaller"?

                  Because that would mean ten times bigger, or just "ten times". The point is that "times" and "smaller" are not oxymoronic because they are not antonyms. The product of two numbers is not necessarily larger than the two numbers, ergo "times" does not necessarily mean "larger in magnitude".

                  Why does no one use a fraction with the word "times" colloquially?

                  Because it's awkward to say "One hundreth times the size". You would say "One hundreth the size", or if the fractio

              • by AP31R0N (723649)

                Wow. i'm about as pedantic as they come, but this is just silly.

                You've hit the nail on the head. One tenth the size and ten times smaller mean the same thing, neither is confusing. The latter might even be easier for both listener and speaker when you deal with non-round numbers. It's easier to think in whole numbers than fractions.

          • by albedoa (1529275)
            I honestly did not think my post would be replied to by someone who has less than a basic understanding of math.
    • by Kjella (173770) on Wednesday July 29, 2009 @09:22AM (#28866025) Homepage

      10^1 times smaller = 10^-1 times bigger, never really managed to see the problem with it. It's perfectly unambigious since it makes no sense to refer to less than nothing. Things like there/their/they're that actually have three different meanings are much more annoying.

      • by ScentCone (795499)
        It's perfectly unambigious

        No, the word smaller is entirely ambiguous in this case because it assumes that one thing is small (compared to what?), and another this is ten times more so. But if you don't have some baseline, the use of smaller ("more small than the first thing, which is already small, and here's why we consider it to be small...") makes no sense. Use of "smaller" presumes familiarity with the overall scale of things, and why the two sizes in question mean something, in relation to the larg
      • by HTH NE1 (675604)

        10^1 times smaller = 10^-1 times bigger, never really managed to see the problem with it.

        If you accept "10 times smaller" == "1/10 times bigger" (and that the latter makes sense), what does "1/10 times smaller" mean? Does "smaller" contradict or re-enforce the figure?

    • by nedlohs (1335013) on Wednesday July 29, 2009 @09:40AM (#28866265)

      It's standard English and has been for hundreds of years.

      Yes mathematically it makes no sense, but language isn't mathematics. And look you understood that it meant 1/10th and 1/100th so from a linguistically it expressed what was intended just fine, even to people who think in math instead of language.

      Unless you're arguing "smaller' needs a qualifier to indicate it means volume. Even that seems a stretch since there are only two options, volume and mass, and the mass is taken by the 100x part.

      • by Tetsujin (103070)

        It's standard English and has been for hundreds of years.

        Yes mathematically it makes no sense, but language isn't mathematics.

        In this case, it is. The language in question is describing a mathematical relationship: due to the use of the inverse scale ("smallness") the meaning of that kind of statement is widely understood, but not according to one consistent interpretation.

        • by nedlohs (1335013)

          It makes perfect to anyone who isn't intentionally being an idiot.

          That it's describing a size/mass difference doesn't make it mathematics. "A is X times less B than C" means that feature B of A is 1/X that of C. It's the same thing as "C is X times more B than A" but allows the speaker/writer to put the import thing at the start instead of end.

          Has been for 300 years (and probably longer). Isn't going to change because math lovers dislike it.

    • by Chris Burke (6130)

      10 times smaller?
      100 times less massive?

      Isn't it 1/10 the size and 1/100 the mass?

      Why yes, that is precisely what "10 times smaller" and "100 times less massive" means.

      I know I'm picking nits, but this is slashdot. People should know better.

      Yes, you should know better. The language is fine.

      I understand it is simply a colloquialism arising from poor grammar among the masses, but in the case of a scientific article, poor writing makes it more difficult to take the writer seriously.

      Yes, poor grammar from the

      • by albedoa (1529275)
        Really? That's what those two terms mean "precisely"? Come on, if you're trying to troll, try harder.
    • Re: (Score:1, Insightful)

      by Anonymous Coward

      . . . this is slashdot. People should know better.

      Why do you seam two think that geeks are intelligenter than you're average citizen? You should no that they aren't just by reading most of the comments that get posted hear.

    • I think that in this case, size and mass are not really interchangeable...they might be somewhat related, but not quite 1 for 1

    • by khallow (566160)

      In order to be "10 times smaller than $foo" or "100 times less massive than $foo" doesn't there need to be another point of reference?

      Zero is already an implied point of reference. Sure the colloquial phrase isn't mathematically rigorous, but it doesn't need much work to become so. You should find something else to angst about.

  • The finding could lend unique insights into how galaxies form stars in the early universe.

    Yes we got that from all the other thousands of astronomy articles reporting new findings. This unifying goal of astronomers better be the question to 42.

  • by The_mad_linguist (1019680) on Wednesday July 29, 2009 @08:37AM (#28865399)

    Great, another overpriced expansion pack. I guess sales from the last time they added a class have dropped, so astronomers are making new areas and classes rather than trying to balance the existing content.

    NERF ANDROMEDA!

  • Are they green? Affected by the greenfly? The end of the universe is nigh! Roberto
  • by grimJester (890090) on Wednesday July 29, 2009 @08:56AM (#28865655)
    Since there are 250 of them between 1.5 billion and 5 billion light years away, you have roughly 2 per billion light year sphere. If we could expect to see an average of two within a billion light years from us, meaning within a billion years back, perhaps they still exist and we just don't happen to have any nearby?

    Given their density within the 5 billion light year sphere, it should be possible to calculate the odds of having 1.5 billion light years to the closest one.
    • Re: (Score:3, Informative)

      by DoubleEdd (178052)

      It's not quite so straightforward due to the complexities of how the peas are actually selected, I think. http://arxiv.org/pdf/0907.4155v1 is the paper - section 2 and 5 might be of interest with respect to this sort of question.

    • by Waveney (301457)
      They are green due to the redshift, any "Peas" closer than 1.5 GLY would be blue.
    • by khallow (566160)

      Since there are 250 of them between 1.5 billion and 5 billion light years away, you have roughly 2 per billion light year sphere. If we could expect to see an average of two within a billion light years from us, meaning within a billion years back, perhaps they still exist and we just don't happen to have any nearby?

      It's 250 out of a mere million galaxies in the study. That would be 0.025% of all galaxies in the survey which is a wee bit higher.

  • Why a new class? (Score:3, Interesting)

    by east coast (590680) on Wednesday July 29, 2009 @09:36AM (#28866215)
    We already have dwarf galaxies, so it's size doesn't matter. I've never heard of a galaxy class based on color. Is it the star creation rate? Does this have a morphology that is prior unknown? The article didn't seem to clear on this.
    • by jschen (1249578)
      Expanding on one of those questions, how does analyzing the light tell us about the rate of star formation? That's a very interesting statement. From the article, "By analyzing their light, Cardamone determined how much star formation is taking place within the galaxies." How does that work?
      • Re: (Score:3, Informative)

        by DoubleEdd (178052)

        Basically young stars have a different kind of emission to old stars. You can essentially count up the amount of light from young stars and work out how much star formation you need to have that population.

      • Re:Why a new class? (Score:4, Informative)

        by wanerious (712877) on Wednesday July 29, 2009 @10:08AM (#28866697) Homepage
        If you look at a population of stars and see lots of blue or UV light, it must be coming from very hot, massive stars. We also know that these stars don't live very long, so they must have formed recently --- this area must then be a region of star formation. The degree to which the overall spectrum is skewed towards the blue gives a rough indication of the star formation rate.
    • Re: (Score:3, Informative)

      by DoubleEdd (178052)

      HST images were needed to investigate the morphology - the shapes just couldn't be picked out in the original images as the galaxies are so compact. However, it looks like a number of them have complex shapes hinting that they are or have recently been involved in mergers with other galaxies. We don't have much to go on at the moment though.

    • We already have dwarf galaxies, so its size doesn't matter. I've never heard of a galaxy class based on color.

      Well, according to Probert, Galaxy Class [probertdesigns.com] is duck-egg blue with sky blue aztecing... It was just when they filmed it that they desaturated the color a bit to give it the more grayish appearance seen on TV. Also, the smooth hull seen on the early model was intentional, as one would expect that on a massive ship, small details would be almost impossible to pick out. But, of course, that's not what audiences expect: if something looks plain, it looks fake... So later on features like the large lounge window

  • by cayle clark (166742) on Wednesday July 29, 2009 @10:39AM (#28867239) Homepage

    I've spent a lot of hours classifying galaxies at GalaxyZoo. The abstract sense of making a tiny contribution to research gets thin real fast. What keeps me coming back is the surprise factor. You'll click away sorting boring balls and streaks and then up pops a perfect barred-spiral, or a swooshy collision or an oddity that doesn't fit any of the categories, and wakes you up. There are millions of galaxies in the deep-field surveys that are the source, most of them never looked at individually, and you never know what the software will toss up next.

    The site has an active and supportive forum community, and it was in the forums that the users -- not the astronomy post-docs who run the site -- first commented on the little green balls, suggested they might represent a unique class, and started collecting them as posts on a thread. There are user-run threads going on for other odd types of galaxy some of which might ultimately turn into research topics as well.

  • by czarangelus (805501) <iapetus&gmail,com> on Wednesday July 29, 2009 @11:05AM (#28867771)
    Why is it believed that galaxies formed only in the early universe? Personally, I find a picture of the universe that has a definite beginning to be a form of stealth creationism. Everything we know about nature is cyclical, always changing, reproducing, and eternal. It's easy for people to accept that the universe has no "center" but most people still cling to the idea that it has a beginning. I think stars and galaxies are life-forms which have defined stages and which reproduce. Funny that ~99% of the universe is supposed to be invisible, yet-to-me-detected forms of strange matter when we don't even have a basic understanding of the 99% of matter which we CAN see - that is, plasma. Thinking of all galaxies as being old just fits into a paradigm of ignorance which defines modern cosmogony. Nobody knows what gravity is or how it operates. The gravity wave detectors they sent up detected a whole lot of nothing. In space, we're told, there are "frozen" magnetic fields not induced by electric currents. I have a suspicion that the only good thing we've gotten out of astrophysics for the past 50 years is observational data - the theories, at least, are junk.
    • Re: (Score:3, Informative)

      by DragonWriter (970822)

      Personally,, I find a picture of the universe that has a definite beginning to be a form of stealth creationism.

      There may have been a time when we didn't have tools for explaining the universe besides appeals to personal aesthetics, but today we've got things like formulating hypothesis that explain past observations and lead to empirically falsifiable predictions of future observations, and then constructing experimenets to attempt to falsify those predictions.

    • We like the theories because no one has come up with anything better and they have made successful predictions that have been verified as our technology improves. Look at the COBE mission, designed to chart the energy of the Cosmic Background Radiation. Before it was launched predictions were made about what would be seen, predictions based upon Big Bang Cosmology (specifically, that the universe used to be really, really hot), as it turns out, the data gathered by COBE agreed precisely.

      What about nature

      • Re: (Score:3, Funny)

        by czarangelus (805501)
        We know for a fact that the universe we see isn't the whole universe - ie; the subject of the Hubble Volume. The universe seems to me to grow eternally in relation to the subtlety of the instruments we use to regard it.

        For the record, everything about Big Bang cosmogony references redshift as being a property of distance. There does not explain several celestial objects where a high redshift object is physically connected to a low-redshift object. I have heard an alternate theory that redshift is a prope
  • and innovate very little. While the smaller, more agile ones foster the biggest stars. Then they attract more matter, merging into bigger galaxies, and become a monopoly.
  • We have a universe filled with Green Pea-ness.
  • "They're growing at an incredible rate,' said Kevin Schawinski, a postdoctoral associate at Yale and one of Galaxy Zoo's founders.

    I'm just an ignorant computer geek, so I'd like to know how these galaxies are growing.

    Are they simply superdense and spawn new stars as they expand? Or are they drawing material from some outside source?

    Here's my totally crackpot theory: Green Pea galaxies are fed from "white holes" (tm) that spew raw material into the nascent galaxy. These "white holes" (tm) are connec

  • by PaganRitual (551879) <splagaNO@SPAMinternode.on.net> on Wednesday July 29, 2009 @06:57PM (#28875671)

    The galaxies, which are between 1.5 billion and 5 billion light years away, are 10 times smaller than our own Milky Way galaxy and 100 times less massive. But surprisingly, given their small size, they are forming stars 10 times faster than the Milky Way.

    Isn't there some sort of theory about time and it's constant slowing or something? If something appears 5 billion light years away and yet appears to be forming stars 10 times faster than our local system, could that not be somehow relevant to the passage of time either 5 billion years in the past?

    If you can't read this because, when I press post, the entire universe changes into something completely new, then I'll know that this means that I was right and that I fucking solved it.

    If you can read this line, then let it be known that I've had a lot of coffee this morning, and very little food. That's my story and I'm sticking to it.

  • by physburn (1095481) on Thursday July 30, 2009 @01:36AM (#28878249) Homepage Journal
    Somewhere between an elliptical galaxy and a globular cluster sitting on there own, with a very high rate of star formulation. Oh, and a very odd color, there aren't any green stars (nothing glows green hot its doesn't fit in the color vs temperate diagram), and the only common gas thats green is one of particular types of oxygen ions. The green color is due to the red-shift of the objects. Full of new stars the green pees (hate the name), would shine bright blue, until the red shift, turns the blue to green, (is that clear?)

    ---

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