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Astronomers Find Unusual Star

Posted by samzenpus on from the one-of-these-things-is-not-like-the-other dept.

First time accepted submitter JoshuaZ writes "Astronomers have found an unusual small star. SDSS J102915+172927 is a small faint star with very little of any elements other than hydrogen or helium. The star's composition is surprising (Pdf) since standard theories of star formation require heavier elements in small stars in order to allow the stars to be heavy enough to come together. Possibly the most unusual aspect of this star is the complete non-detection of lithium which would be expected in a star of this size. The only elements created shortly after the Big Bang were lithium, hydrogen and helium, and the star should have lithium levels much higher since they should correspond closely with the levels believed to have been formed shortly after the Big Bang."

4 of 203 comments (clear)

  1. Re:Well then by SharpFang · · Score: 3, Interesting

    That's no star. It's artificial sun.

    --
    45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
  2. So, it's like Jupiter? by BenSchuarmer · · Score: 3, Interesting

    Jupiter is also like 99.7% hydrogen and helium, but I guess they're assuming that the Sun gobbled up most of the heavier elements when our solar system was forming.

  3. Re:Well then by repapetilto · · Score: 3, Interesting

    Someone mined the heavier elements.

  4. Re:have direction, but not distance by SplashMyBandit · · Score: 3, Interesting

    That's because it is so damn hard to measure distance, so sometimes even an approximate distance is not given (but as you imply, distances should be given when known or a reasonable guess is available). That's because the most straightforward way requires you to know the 'extinction' of light towards your particular star. That means, you need to have a measurement of blocking effect of (non-emitting) gas nearby and hope it applies to your (hopefully nearby) object of interest. If you are lucky you'll get a reasonable estimate for distance that is probably within an order of magnitude of the true value, and sometimes you might even get down to a factor of two in uncertainty. And this is just for stuff relatively close in our galaxy. Getting distances elsewhere can be even harder. Disclaimer: IAAFA (I am a former astrophysicist).