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Orion Nebula Gets New Milepost Marker, Now Closer

Posted by CowboyNeal on from the objects-in-mirror-may-be-closer-than-they-appear dept.

twilight30 writes "Discovery News is reporting that 'One of the most famous and scrutinized heavenly objects is 10 to 20 percent closer than we thought, say two teams of radio astronomers who have made some of the most precise cosmic distance measurements ever, with a telescope nearly as big as Earth. The Orion Nebula is the closest major stellar nursery to Earth, so it has been heavily studied to learn about the lives of stars. Its distance from Earth, however, has long been a matter of uncertainty, with an estimate made about 25 years ago in need of revision.'"

17 of 93 comments (clear)

  1. "a telescope nearly as big as Earth" by Anonymous Coward · · Score: 4, Funny

    That's nothing. They needed a computer nearly the size of Jupiter to process the data.

    1. Re:"a telescope nearly as big as Earth" by opus · · Score: 4, Insightful

      The VLBA was aimed at one of the few radio-wave emitting stars in Orion, which was viewed twice in a single a year. The almost 200-million-mile width of Earth's orbit around the sun allowed the VLBA to serve as one eye, then again as the other eye six months later.

      Wouldn't that be a telescope 200-million-miles wide, using the same poetic license that led them to say they used a telescope as big as the earth.

    2. Re:"a telescope nearly as big as Earth" by glavenoid · · Score: 4, Informative
      Wrong again. The 2 points, ~200 million miles apart were used as points in a measure of parallax. The virtual aperture of the VLBA scope is ~5000 miles diameter, which isn't *quite* "nearly as big as earth". Still a pretty big aperture, even though it's not a complete circular area, the resolution provided is apparently sufficient to measure the stellar (nebular?) parallax wrt M42.

      What I find more interesting in this article is the close relationship alluded to between the trapezium and the nebula...

      --
      I, for one, am looking forward to the inevitable /. beta rollout fallout.
  2. Re:..with a telescope _AS BIG AS the EARTH" ? by Anonymous Coward · · Score: 3, Informative

    It's an interferometer. It's not one telescope the size of earth but many smaller telescopes each collecting samples along a line with a length of about the diameter of Earth. The samples can be processed to give a picture with the resolution of a telescope the diameter of Earth (but it still only captures a small amount of em waves).

  3. Re:question: by The_Mystic_For_Real · · Score: 5, Funny
    Or maybe the nebula is just moving 20% closer every six months!

    Fortunately it will get caught in Xeno's paradox.

    --

    _____

    Thank you.

  4. Re:question: by siddesu · · Score: 3, Insightful

    the sun travels around the galactic center at about 20km/s. even assuming than sun and orion nebula travel away from each other at this speed, for 6 months they'd have moved away at about 6 billion km. this is about 0.00068 light years. since the distance is estimated at 1250+ l.y. give or take 50-60, the error due to the relative movement of the two objects seems accounted for.

  5. Expanding Universe... by CODiNE · · Score: 4, Funny

    Let's just wait a little longer and we won't have to reprint all those textbooks.

    --
    Cwm, fjord-bank glyphs vext quiz
  6. Re:question: by servognome · · Score: 4, Funny

    but if the Orion Nebula is undergoing rapid beta expansion, the measurements would be invalid. I don't know of any way to correct for this phenomenon...
    Release it and figure it out in Service Pack 1.
    --
    D6 63 0D 70 89 81 BB 8E 7B 7C 5F 5D 54 EA AB 73
  7. Closer than we thought... by LordP · · Score: 3, Insightful

    Measured incorrectly, or has the Orion Nebula just been sneaking closing over the last 25 years?

    --
    Nothing is so smiple that it can't be screwed up.
    1. Re:Closer than we thought... by jamesh · · Score: 4, Funny

      Hmmm... 10 to 20 percent closer in 25 years... (gets out calculator)... that means that it will be here in 125 to 250 years!!!

      I for one welcome our invading Orion Nebula overlords.

    2. Re:Closer than we thought... by davburns · · Score: 3, Insightful

      Bower and his colleagues came up with a distance of 1,270 light-years, give or take 76 light-years. That compares with the previous estimate of 1,565 light-years, give or take 266.

      There's still overlap in the uncertainties of the measurements. So it wasn't incorrectly measured, just measured with a 17% error margin. The only ones who are incorrect are the people who quote the estimate without including the uncertainty.

  8. Telescope warning by autophile · · Score: 4, Funny

    Warning: Objects in telescope are closer than they appear.

    --Rob

    --
    Towards the Singularity.
  9. That's easy... by SteveFoerster · · Score: 3, Funny

    ...four elephants standing on the back of a turtle.

    --
    Space game using normal deck of cards: http://BattleCards.org
  10. Translation by Anonymous Coward · · Score: 5, Funny

    >One of the most famous and scrutinized heavenly objects is 10 to 20 percent closer than we thought

    In other words, Natalie Portman moved from Boston to New York.

  11. Re:..with a telescope _AS BIG AS the EARTH" ? by jnik · · Score: 4, Informative

    Actually, we've been doing it for a decade.

  12. Oh My GOD! by grumling · · Score: 3, Funny

    It's coming right at us!

    Looks like I picked the wrong week to stop sniffing glue...

    -Steve McCroskey

    --
    "Well, good luck finding a judge that doesn't run a bestiality site."
  13. Combine the measurements for increased accuracy by SirBruce · · Score: 3, Interesting

    The old measurement was 1,565 +/- 266 LY.

    Bower's new measurement is 1,270 +/- 76 LY.

    Assuming both error bars are correct, then by combining the two measurements we get between 1,299 LY and 1,346 LY.

    Reid's new measurement is 1,350 +/- 23 LY.

    So combining again, we can conclude the Orion Nebula is between 1,327 and 1,346 LY away, or 1,336.5 LY +/- 9.5 LY.