Stories
Slash Boxes
Comments

SoylentNews is people

SoylentNews is powered by your submissions, so send in your scoop. Only 9 submissions in the queue.

Three-Starred System Has Giant Planet

posted by takyon on Thursday April 07 2016, @10:28AM   Printer-friendly
from the hot-mess dept.

butthurt writes:

Reported in The Astronomical Journal (DOI: 10.3847/0004-6256/151/2/45), KELT-4Ab orbits one of the stars in a triple stellar system. Considered a "hot Jupiter" because of its large size and small orbit, it is only the fourth planet that has been found in association with a triple star system. KELT-4A is the brightest star in the system. KELT-4B and KELT-4C, separated from each other by about 10 astronomical units (AU), form a binary, about 328 AU distant from KELT-4A. The system is about 685 light-years from us.

The planet was detected in a survey by the Kilodegree Extremely Little Telescope. Scientific American has a story about the discovery.

Original Submission

 
This discussion has been archived. No new comments can be posted.
Three-Starred System Has Giant Planet | Log In/Create an Account | Top | 10 comments | Search Discussion
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.

  • (Score: 2) by Runaway1956 on Thursday April 07 2016, @03:56PM

    by Runaway1956 (2926) Subscriber Badge on Thursday April 07 2016, @03:56PM (#328515) Journal

    Obviously a pretty smart man - but he's not so hot with basic math - http://www.amazon.com/Three-Body-Problem-Remembrance-Earths-Past-ebook/dp/B00IQO403K/ref=sr_1_1?s=digital-text&ie=UTF8&qid=1460044529&sr=1-1&keywords=cixin+liu+three+body+problem [amazon.com]

    Three suns and a planet is actually a "Four Body Problem".

    --
    “I have become friends with many school shooters” - Tampon Tim Walz
    Starting Score:    1  point
    Karma-Bonus Modifier   +1  
    Total Score:   2  

  • (Score: 2) by AnonymousCowardNoMore on Thursday April 07 2016, @05:36PM

    by AnonymousCowardNoMore (5416) on Thursday April 07 2016, @05:36PM (#328572)

    The mass of the planet is negligible over rather long time scales. It could have been analysed as restricted four body so he's not quite that far off. Here are some just-for-fun nitpicks by an extremely anal jerk (me):

    • The general three body problem is in fact solvable. It isn't solvable analytically but a sequence which converges on the exact answer has been known since the 1930's. Convergence is too slow to be useful but the book seriously overstated how unsolvable it is.
    • Not withstanding the above, you can get almost arbitrarily good approximation using numerical simulation over astronomically short time scales. For astronomically significant periods you'll hit a wall in the form of Lyapunov time but even then you can make some statistical guesses as to what will most likely happen.
    • Spoiler: Vs gur nyvraf pna'g pnyphyngr gur qlanzvpf bs gurve flfgrz npphengryl rabhtu gb cerqvpg qnlyvtug plpyrf, ubj gur uryy qvq gurl fbyir gur vairefr qlanzvpf naq svther bhg ubj znal cynargf gurl fgnegrq jvgu? These aliens must be (a) so smart that they can solve impossible problems and (b) too damn stupid to apply the results.
    • I was very disappointed at how the mystery was resolved. Subatomic particles just don't work that way. All particle physicists reading it must have been crying (and the thermodynamicists crying with laughter).
    • Spoiler: Ba gung gbcvp, dhnaghz ragnatyrzrag qbrf abg nyybj SGY pbzzhavpngvba. A common enough mistake to warrant its own entry.
    • Spoiler: Gurer vf ab ernfba sbe bhe arnerfg fgryyne arvtuobhef gb or nf hafgnoyr nf va gur fgbel. Cebkvzn vf cebonoyl (vs obhaq) va na beovg sne bhg sebz gur bgure gjb fgnef, juvpu beovg rnpu bgure va n avpr fgnoyr flfgrz arne gur onelprager. Gevfbyne qnlf fubhyq arire bpphe jvguva yrff guna n srj Ylnchabi gvzrf sebz gur cerfrag.

    I rather enjoyed the book but felt let down near the end.

    P.S. Liu isn't really that bad at counting. The Trisolarans used their magic particles on his calculator.

    • (Score: 0) by Anonymous Coward on Thursday April 07 2016, @10:52PM

      by Anonymous Coward on Thursday April 07 2016, @10:52PM (#328721)

      The general three body problem is in fact solvable. It isn't solvable analytically but a sequence which converges on the exact answer has been known since the 1930's. Convergence is too slow to be useful but the book seriously overstated how unsolvable it is.

      If you need 10^8000000 terms to solve it, then yes, it is quite unsolvable.

      However [sciencemag.org], . . .

      • (Score: 2) by AnonymousCowardNoMore on Friday April 08 2016, @03:47AM

        by AnonymousCowardNoMore (5416) on Friday April 08 2016, @03:47AM (#328815)

        You are entirely correct. What I mean to say is that the book implies the problem to be unsolvable in principle, especially given that the magic technobabble that the Trisolarans possess in the book should make such a calculation trivial. (It's in one of the ROT13 spoilers.) The special cases don't come into play since they don't apply to this situation but are, of course, beautiful.

    • (Score: 2) by el_oscuro on Friday April 08 2016, @01:54AM

      by el_oscuro (1711) on Friday April 08 2016, @01:54AM (#328765)

      I read the book and while it was good, I am not even sure the three body problem even applies to Alpha Centauri.

      Alpha Centauri is a 3 star system. Cemtauri A and B orbit each other at a distance that varies from Saturn to the Sun and Pluto to the Sun. The 3rd star, Proxima Centauri, is about 0.2 light years away.

      So if there was a planet in an earth like orbit around Centauri A or B, the second star would be a distant and cold, like the sun is to Saturn at least. Sure it would have significant effects on the orbit, climate, and tides of the planet. But it wouldn't be the planet destroying monster the book depicts. And Proxima Centauri, a brown dwarf 0.2 light years away wouldn't be a factor at all.

      --
      SoylentNews is Bacon! [nueskes.com]

      • (Score: 2) by AnonymousCowardNoMore on Friday April 08 2016, @04:00AM

        by AnonymousCowardNoMore (5416) on Friday April 08 2016, @04:00AM (#328823)

        The three body problem applies if we consider long time periods, making the system chaotic.

        It really depends where the planet/star orbits. Over a time period of several Lyapunov times, its orbit will probably be highly unstable regardless of the original orbit. But such chaotic behaviour normally starts with a body in a metastable orbit, where it stays for a number of Lyapunov times before briefly entering an unstable orbit which flings it into a star (unlikely), out of the system (likely) or (also unlikely but possible) into another metastable orbit, where it stays again for a long time. The sort of near-far dance in the book I can't see happening in a real system, especially over time periods that are short on the scale of civilisations.

    • (Score: 0) by Anonymous Coward on Friday April 08 2016, @07:44PM

      by Anonymous Coward on Friday April 08 2016, @07:44PM (#329119)

      V qba'g fcrnx Jryfu, lbh vafrafvgvir pybq!