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Thread: Interesting extrasolar planet discoveries

  1. #1261
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    Quote Originally Posted by Kullat Nunu View Post
    Okay, I used the term "compact" to indicate the system has several planets orbiting near the star, unlike in our Solar System. Which doesn't necessarily mean "fully packed". And of course, we don't know much of the systems, not ever those who have planets detected.
    Yeah, that hole in the middle is one of the distinguishing features of the solar system. There's room for several planets inside the orbit of Mercury. I suppose 'compact' is as good a word as any. Maybe the Solar System is a "doughnut" system.

  2. #1262
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    Quote Originally Posted by Kullat Nunu View Post
    Yes they are.

    But a note of caution: In both cases, the detected signals are very weak and at the edge of detectability. So they're not confirmed, yet.
    Another note of caution: Steve Vogt is one of the authors.

  3. #1263
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    The Gliese 581g guy? Now I'm embarrassed to have even gotten excited over those results.

  4. #1264
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    Well, don't get underexcited either. I believe the planets have a good chance of being there, considering the configuration of the Tau Ceti system is very typical for a Sun-like star (more than our own!) and there seems to be a 5e:2f resonance. But it probably takes years before they can be confirmed beyond reasonable doubt.

    Another note of caution: Steve Vogt is one of the authors.
    So what? So is Paul Butler and many others. The lead author is Mikko Tuomi who has published several papers on possible additional planets by reanalyzing available RV data.

  5. #1265
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    Quote Originally Posted by Kullat Nunu View Post
    Well, don't get underexcited either. I believe the planets have a good chance of being there, considering the configuration of the Tau Ceti system is very typical for a Sun-like star (more than our own!) and there seems to be a 5e:2f resonance. But it probably takes years before they can be confirmed beyond reasonable doubt.



    So what? So is Paul Butler and many others. The lead author is Mikko Tuomi who has published several papers on possible additional planets by reanalyzing available RV data.
    I thought you were referring to the GJ667C paper. I know that is the one I was referring to and the one Brett explicitly mentions in the post which is the grandparent of mine.

  6. #1266
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    15 new Neptune or larger sized gas giants in habitable zones of their stars. This doubles the number of gas giants known to be in their star's habitable zone:

    http://blog.planethunters.org/2013/0...et-candidates/

    Plus almost 30 other planet candidates announced by the Planet Hunters project.

  7. #1267
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    Kepler has found two new solar systems, both with habitable zone planets.

    Kepler-62 is K2 main sequence star (seven billion years old) with five identified planets. Planets B, C, and D are all your typical "closer than Mercury" planets in very close orbit around the star, but Kepler-62e is a super-Earth near the inner boundary of the star's estimated habitable zone, and Kepler-62f is a super-Earth right in the middle of the star's habitable zone. 62e is 60% larger than Earth and probably a super-Venus, while 62f is about 40% larger and sits between the equivalent of Earth's and Mars' orbits (which is good). All in all, it's good stuff, and I'm hoping that they stand up in independent verification, whenever it arrives.

    Kepler-69 is a G-type star with two planets. Kepler-69b is a close-up hot super-Earth, while Kepler-69c is 70% larger than Earth and theoretically inside the star's habitable zone. However, it's right on the inner edge, and that means that (if it exists) it's almost certainly a super-Venus.

    EDIT: There's a very good, detailed article at Sky and Telescope about this discovery.
    Last edited by TheBrett; 2013-Apr-19 at 03:02 PM.

  8. #1268
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    1200 ly? Phooey. Hey Q! swap this out for Barnard's star willya?

  9. #1269
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    That does suck. It would be nice to find a planet like that only a few light-years away, because we then might have a chance of direct imaging it with the proper set-up sometime in the future.

  10. #1270
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    Gliese 667Cc is "only" 24 light years away, and it also orbits a much dimmer red dwarf star, so it's possible it could be directly imaged in the near future. Of course it's likely tidally locked, but it is well within its habitable zone so the chances are good it has liquid water.

  11. #1271
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    Mercury is tidally locked to the Sun, but in a 2:3 resonance, so it does have a day/night cycle and relatively even surface temperature. Is that considered unlikely for planets close to red dwarfs?

  12. #1272
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    1924 new KOIs (Kepler Objects of Interest) added to database covering quarters Q1-Q12 (May 2009 – March 2012).

  13. #1273
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    Has this directly observed giant:
    http://www.eso.org/public/archives/r...4/eso1324a.pdf
    been discussed here?

  14. #1274
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    From Reuters
    A neighbor star has at least six planets in orbit, including three circling at the right distance for water to exist, a condition believed to be necessary for life, scientists said on Tuesday.

    Previously, the star known as Gliese 667C was found to be hosting three planets, one of which was located in its so-called "habitable zone" where temperatures could support liquid surface water. That planet and two newly found sibling worlds are bigger than Earth, but smaller than Neptune.

    "This is the first time that three such planets have been spotted orbiting in this zone in the same system," astronomer Paul Butler, with the Carnegie Institution in Washington, D.C., said in a statement.

    Scientists say the discovery of three planets in a star's habitable zone raises the odds of finding Earth-like worlds where conditions might have been suitable for life to evolve.

    "Instead of looking at 10 stars to look for a single potentially habitable planet, we now know we can look at just one star and have a high chance of finding several of them," astronomer Rory Barnes, with the University of Washington, said in a statement.
    The research is being published this week in Astronomy & Astrophysics.

    Here is the UT blog posting on it
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  15. #1275
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    That looks like a lot of planets close in. I wonder if one will be ejected in the next eon or two.

  16. #1276
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    Sky and Telescope splashed some possibly cold water on the Gliese 667C:

    But these [M dwarf] stars also have a violent youthful phase of magnetic outbursts and flares, during which they would bombard close-in planets with ultraviolet and X-ray radiation, perhaps leaving their planets sterile for billions of years. This torrid history leaves astronomers wrestling with a so-what question: even if we do find these planets, are they actually habitable?
    I suppose we won't really know until we can do spectrography on the atmosphere of one of these planets.

  17. #1277
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    But I wonder if these ultraviolets and X-rays are so dangerous to life ?

    After all the UV's are easily blocked by water and, in addition , are supposed to be a positive factor for abiogenesis. The problem is really serious for land based life, but marine life could manage well.
    The X rays are nastier, but everything depends on the dose. And some water meters should be sufficient to block them. Or not ?

    In any case I don't see which would hinder a microbial life.
    Last edited by galacsi; 2013-Jul-03 at 09:43 PM.

  18. #1278
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    Quote Originally Posted by galacsi View Post
    But I wonder if these ultraviolets and X-rays are so dangerous to life ?

    After all the UV's are easily blocked by water and in addition are supposed to be a positive factor for abiogenesis. The problem is really serious for land based life but marine life could manage well.
    The X rays are nastier but everything depends on the dose. And some water meters should be sufficient to block them. Or not ?

    In any case I don't see which would hinder a microbial life.
    Coupled with the fact that M class stars will ultimately remain stable for much longer periods than our own sun (G2). Doesn't this suggest that after this initial "violent" period of intense radiation, etc (which again is thought to perhaps be an ingredient in Earth's own abiogenesis event(s)) that any such planets that do maintain water would have a long stretch of runway (longer than Earth itself had) from which to spawn life??

  19. #1279
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    Fraser covers this on UT, but I thought it worth repeating: there are now over 1000 confirmed exoplanets. Wow!
    At night the stars put on a show for free (Carole King)

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  20. #1280
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    'Hotter Than Lava': Scientists Discover 'hellish' Planet Where Metal Vaporises Instantly
    https://www.republicworld.com/techno...instantly.html

    hydroxyl molecule signature in exoplanet
    https://eurekalert.org/pub_releases/...-adf042721.php

    Astronomers detect new chemical signature in an exoplanet's atmosphere using Subaru Telescope
    https://phys.org/news/2021-04-astron...tmosphere.html

    New Exoplanet discovered orbiting young Sun-like star
    https://idw-online.de/de/news767047

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