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NASA Finds Star With a Tail

Posted by samzenpus on from the streaking-across-the-universe dept.

Andrew Stellman writes "NASA astronomers held a press conference announcing that a new ultraviolet mosaic from NASA's Galaxy Evolution Explorer shows a speeding star named Mira that's leaving an enormous trail of "seeds" for new solar systems. Mira is traveling faster than a speeding bullet, and has a tail that's 13 light-years long and over 30,000 years old. The website has images and a replay of the teleconference."

4 of 233 comments (clear)

  1. Faster than a speeding bullet? by SamP2 · · Score: 5, Insightful

    Newsflash: Our own Sun's velocity is 217 km/s (relative to the galactic center) and 20 km/s relative to the average speed of neighboring stars.

    For comparison, a "speeding bullet" slugs anywhere from around 1km/s (sniper rifle) to ~100m/s (short-barrel pistol).

    In addition, Wikipedia states that Mira's velocity is 63.8km/s -- which is actually slower than our own's sun (which has no "tail"), leading to two conclusions: (1) Mira's tail is caused by some other factor than it's velocity alone, and (2) Mira's speed is also so faster than a "speeding bullet" beyond comparison. In other words, the comparison is not just off-scale but also irrelevant.

    If you insist on using laymen's "cool-sounding" metaphors to describe scientific phenomena, at least check your facts and context, or you will just make a moron out of yourself.

    1. Re:Faster than a speeding bullet? by SamP2 · · Score: 2, Insightful

      May I ask for a reference to your statement that the speed of -sound- in interstellar medium is ~100km/s?

      For all I know, the speed of sound in a medium increases with a medium's density. Pure vacuum transmits no sound at all. The speed of sound in water is much faster than that in the air.

      Note that I'm referring to -sound- specifically, rather than any other form of transmitted waves (subatomic radiation, whether beta or gamma, for example stellar pulses, and the like, are not "sound" in their own right, even though they can be CONVERTED into sound). Sound (and the use of the word "sonic") refers to waves in molecular matter, not subatomic particles. Extremely low density medium will result in longer interaction time between individual molecules, and thus, if any sound is possible it all, it would be much slower (and with much lower frequencies as well).

  2. Relative to what? by mukund · · Score: 4, Insightful

    Mira is traveling faster than a speeding bullet, relative to what object?

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    Banu
  3. This seems really wrong... by Ralph+Spoilsport · · Score: 2, Insightful
    TFA did speak:

    Mira is traveling faster than a speeding bullet, and has a tail that's 13 light-years long and over 30,000 years old.

    Hrrrmmm. OK. So, a light year is about 5,879,000,000,000 miles.

    So, 13 light years would be 76,427,000,000,000 miles.

    Now divide that by 30,000 years and we get 2,547,566,666.667 miles. now there are 8,760 hours in a year, so if we divide 2,547,566,666.667 by 8,760, we get 290,818.113 miles per hour. Now, that IS fast, especially given the average asteroid skips along at 40,000 mph. But it's not THAT fast - it would take that star an hour to go from here to the moon. If it did it in 5 minutes - yeah, that's fast. But an hour? Heck - our feeble crappy spacecraft get there in a few days...

    RS

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