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The Milky Way May Be 50 Percent Bigger Than Previously Thought 59

astroengine writes: A ring-like filament of stars wrapping around the Milky Way may actually belong to the galaxy itself, rippling above and below the relatively flat galactic plane. If so, that would expand the size of the known galaxy by 50 percent and raise intriguing questions about what caused the waves of stars. Scientists used data collected by the Sloan Digital Sky Survey to reanalyze the brightness and distance of stars at the edge of the galaxy. They found that the fringe of the disk is puckered into ridges and grooves of stars, like corrugated cardboard. "It looks to me like maybe these patterns are following the spiral structure of the Milky Way, so they may be related," said astronomer Heidi Newberg. In other Milky Way new, a Cambridge team has found nine new dwarf satellites orbiting our galaxy. Some of them are definitely dwarf galaxies, and the others may be the same, or globular clusters.
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The Milky Way May Be 50 Percent Bigger Than Previously Thought

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  • by ArsonSmith ( 13997 ) on Tuesday March 10, 2015 @06:54PM (#49229231) Journal

    As you can see from the middle of this picture of the milkyway:

    http://www.collectingcandy.com... [collectingcandy.com]

    • by Tablizer ( 95088 )

      We all put on a little weight in middle age

    • Conceptually, I understand that everything is on the internet. It's nice to actually see it from time to time. Especially when it's not porn.

      • Conceptually, I understand that everything is on the internet. It's nice to actually see it from time to time. Especially when it's not porn.

        yeah, I wonder how parent post found the link. Probably browsing for something..

    • by Anonymous Coward

      Hey don't you love these articles that have trackers all over the place?

      The Discovery.com link got me 16 trackers when I enabled JS. Kind of a record.. But not a positive one.

      How about blocking any posts referencing abusive sites like this one. Freedom of Speech does NOT include freedom to spy !!!!!!!!!!!!!!!!!!!!!

      How about we call bad sites bad sites. Btw Slash-dot tried to give me "just" 5 trackers.

  • by allcoolnameswheretak ( 1102727 ) on Tuesday March 10, 2015 @07:08PM (#49229343)

    Wow, so this is how little we really know about our cosmic surroundings...
    There is this big mystery about why stars further away from the galactic center orbit at the same speed as the inner stars, defying the laws of gravitation, scientists invent dark matter and other interesting theories, then it turns out we misjudge the size of our own galaxy by 50 percent?

    How can we even think about stuff like that if we don't even really know how large our galaxy is?

    • You have a tough time being coherent, don't you?

    • ELI5: This is like adding the length of your hair to your height. It's always been there, but you just decided that it's important enough to add it to your reported height. Are you taller? Nothing really changed. The Milky Way is the same size it was before. We just decided that some extra stuff that's always been there should be include due to it's observed behavior. We do not know nothing. We are always learning.
      • We just decided that some extra stuff that's always been there should be include due to it's observed behavior.

        The important part, which you seem to have missed with your hair analogy, is that recent analysis of its behavior characterizes it as part of the Milky Way, rather than just a tidally-ripped passing galaxy.

        It's definitely not "hey look I can make myself 50% taller by styling my hair in a Marge Simpson bouffant."

    • Pretty much all pop-physics is guessing and jackoffery, suited only for Morgan freeman to present it on "Through the Wormhole", accompanied by a terrible metaphor / physical demonstration presented by a celebrity "scientist" who has devoted their entire life to this "research".

    • by Anonymous Coward
      We already knew we were missing large amounts of normal matter. Several estimates of how much dark matter there also give estimates of how much normal matter there is too, and it is significantly larger than what we can account for, so there is still a lot more normal matter to be found. That isn't particularly relevant here since these stars were already known about and known to be around the galaxy, but the question was whether they were a part of the galaxy's structure or a transient phenomena.
    • Are you high?

      We can't observe our galaxy from outside our galaxy. Not yet, at least.

      We are far more knowledgeable about other galaxies than we are about our own. This is still true even if dark matter turns out to be bad assumptions.

      Most of the Milky Way is hidden from direct observation, unless you want to man a telescope for half of the 200 million years needed to rotate around the bigass whatever the hell it is at the center of it all.

      Does "size" mean mass or space? Because that's really what you need

    • It's less about knowing, it's just that we've changed that labelling to consider those stars part of our galaxy. Just like we didn't suddenly discover Pluto just because it was relabelled as a minor-planet
  • by Anonymous Coward

    50% error? That's horrible!! I better see some high profile firings VERY SOON.

  • On the plus side, plenty of extra room for expansion. On the minus side, the commute still utterly sucks for 99.999% of it.
  • Those are satellite galaxies as I learned in childhood, no demoting them to "dwarf galaxies" on my watch you spring chicken tenderfoots!

  • by techno-vampire ( 666512 ) on Tuesday March 10, 2015 @07:47PM (#49229657) Homepage
    Do they mean that its volume is 50% more than we'd thought, or its mass? Judging from TFS, I'd guess the former, but as written, it's ambiguous.
    • Honestly, Percentages are a shit way to compare two things together (in this case, present tense Milky Way vs past tense Milky Way). Some of it may be because a chronic lack of sleep gives me some sort of mental handicap regarding the english language, and some of it is because I CANT TELL WHICH THING IS BEING REFERENCED.
      Walk with me:

      If we are using the past tense Milky Way as our frame of reference, and give it, for this example, and arbitrary size of say, 8 units. and say that the present tense Milky
    • Only size matters.
    • 50% more nougat
    • by Baloroth ( 2370816 ) on Tuesday March 10, 2015 @10:27PM (#49230581)

      Volume. Well, maybe area, TFA isn't terribly clear (or possibly even radius, now I read it again. Size could refer any of the three. Pretty sure they mean radius, though, now I look at it closer). Not mass, though, that'd be a hell of a lot of extra mass. Basically, the problem is there is a ring of stars around the outer edge of the Milky Way. Astronomers aren't entirely sure where it comes from: if it originated from the Milky Way, and therefore is part of our galaxy properly speaking, or if it's the remnants of a dwarf galaxy that was scattered when it ran into us, or came from some other source. That would tell us a bit more about galaxy formation (or raise more questions about formation, which is almost the same thing).

    • From the article:
      "Incorporating the ring into the map of the Milky Way expands the galaxyâ(TM)s span from 100,000 light-years to 150,000 light-years, said astronomer Yan Xu, with the National Astronomical Observatories of China and a former visiting scientist at Rensselaer."

      It would appear by "size" they are refering to diameter. When you increase the radius of a circle by 50% I believe you more than double the surface area. In this case, depending on the density of matter in the extra volume of space

  • well, will not know until we go.
    • Currently going [nasa.gov]. You may have to wait a bit more to get the answer, though. Not sure slashdot's gonna still be around at that time.
  • So if they haven't even accounted for a significant fraction of our own galaxy, what does that mean about dark matter?

    If they can't account for or properly locate the visible mass in the universe, dark matter could be largely a cosmic fudge factor that accounts for ordinary mass that hasn't been observed or located precisely.

    • by Xtifr ( 1323 )

      So if they haven't even accounted for a significant fraction of our own galaxy, what does that mean about dark matter?

      As far as I can tell from a bit of quick research, absolutely zilch. Since dark matter is mainly hypothesized to explain the observed motion of galaxies, and most of the evidence for it comes from observing other galaxies and, especially, galactic clusters, the size of the Milky Way has no bearing.

      Also, as someone else pointed out, this is about volume in any case; the actual mass of the Milky Way is probably not a lot different from previous estimates—but all estimates of the size and or mass of the

  • For the devs at Elite: Dangerous, the April update will have them working around the clock

  • Take that Andromeda! It's we who are going to eat you.
  • Milky Way is larger than Andromeda? Andromeda has always been thought to be larger, but I recall an article a couple years back saying they thought the Milky Way was larger than previous thought but not 50%...

  • If you'd quit stuffing yourself on all those burgers and fries, you could lose some weight, dammit!

Always draw your curves, then plot your reading.

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