Notices
Results 1 to 11 of 11

Thread: Richest Planetary System Discovered

  1. #1 Richest Planetary System Discovered 
    Moderator Moderator Dishmaster's Avatar
    Join Date
    Apr 2008
    Location
    Heidelberg, Germany
    Posts
    1,624
    A group of Astrophysicists from Geneva have discovered what seems to be the extrasolar planetary system with the biggest number of planetary candidates so far. They have used the radial velocity method with the HARPS instrument attached to the ESO 3.6 m telescope on La Silla in Chile (no, not the VLT). The system of 5 to 7 planetary candidates around a sun-like star (spectral class G1V) is only 127 Ly (= 39 pc) away. The five clear detections are probably Neptune-like. The two additional tentative detections comprise a Saturn-like object and another planetary candidate of about 1 earth mass. The most interesting detail is that all orbits seem to be almost circular like in our solar system. Furthermore, with an estimated age of 7.3 billion years, it is even older, and the orbits still appear to be stable.

    The fact that apparently no Jupiter sized object is present in this system clearly shows the observational bias of most of the other detections so far, because such heavy bodies are much easier to detect. So, it seems, the number of configurations concerning the amount of planets and their mass distribution is much larger than previously anticipated.

    More information can be found in the ESO Press Release and the research paper linked there.


    Reply With Quote  
     

  2.  
     

  3. #2  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,169
    This is one of the most exciting finds in the field for ten years. The observational biases will progressively disappear as we get more sophisticated detection systems up and running. Only then will be able to start to formulate meanigful theories of planetary formation based upon a sizeable and representative sample of planetary systems.

    Plus, at only 127 light years away, it's practically on our doorstep. I look forward to some of my great-great-great-great-great-great-great-great-great-great-great-great-great-great-grandchildren visiting it.


    Reply With Quote  
     

  4. #3  
    Suspended
    Join Date
    May 2008
    Posts
    1,096
    I read o bit in a newspaper this morning. As I remember it has a Neptune sized planet in very close to the sun. It seems to be a fairly common theme. You would think that such an orbit surely cannot be that stable, that it must spiral into the central star, but I get the impression that such planets have been on an inward crawl for many millions if not billions of years.
    Reply With Quote  
     

  5. #4  
    Forum Bachelors Degree x(x-y)'s Avatar
    Join Date
    Jul 2010
    Location
    UK
    Posts
    462
    Very interesting. I remember reading about this a few days ago.

    What I find very interesting is that it has a planet of ~1 Earth Masses, which might suggest a hospitable environment. I'm not sure if it's in the habitable zone (or near to it) of that solar system though?
    "Nature doesn't care what we call it, she just does it anyway" - R. Feynman
    Reply With Quote  
     

  6. #5  
    Moderator Moderator Dishmaster's Avatar
    Join Date
    Apr 2008
    Location
    Heidelberg, Germany
    Posts
    1,624
    Quote Originally Posted by x(x-y)
    Very interesting. I remember reading about this a few days ago.

    What I find very interesting is that it has a planet of ~1 Earth Masses, which might suggest a hospitable environment. I'm not sure if it's in the habitable zone (or near to it) of that solar system though?
    Well, the signal is not solid, and the mass can be in a wide range, as usual with the radial velocity method. The possible earth mass planet is very close to the star.
    Reply With Quote  
     

  7. #6  
    Forum Bachelors Degree PetTastic's Avatar
    Join Date
    Jul 2010
    Location
    London UK
    Posts
    421
    Quote Originally Posted by Cyberia
    I read o bit in a newspaper this morning. As I remember it has a Neptune sized planet in very close to the sun. It seems to be a fairly common theme. You would think that such an orbit surely cannot be that stable, that it must spiral into the central star, but I get the impression that such planets have been on an inward crawl for many millions if not billions of years.
    Is it possible the star is spinning fast enough for the inner planet to be still above geosync orbit, and therefor not falling in?
    Reply With Quote  
     

  8. #7  
    Moderator Moderator Dishmaster's Avatar
    Join Date
    Apr 2008
    Location
    Heidelberg, Germany
    Posts
    1,624
    Quote Originally Posted by PetTastic
    Quote Originally Posted by Cyberia
    I read o bit in a newspaper this morning. As I remember it has a Neptune sized planet in very close to the sun. It seems to be a fairly common theme. You would think that such an orbit surely cannot be that stable, that it must spiral into the central star, but I get the impression that such planets have been on an inward crawl for many millions if not billions of years.
    Is it possible the star is spinning fast enough for the inner planet to be still above geosync orbit, and therefor not falling in?
    Would you care to elaborate why this is relevant for a stable orbit?
    Reply With Quote  
     

  9. #8  
    Forum Bachelors Degree PetTastic's Avatar
    Join Date
    Jul 2010
    Location
    London UK
    Posts
    421
    I was just thinking about tidal forces from the star on the planet. In the same way the tidal forces of the earth on the moon are pushing the moon into a higher orbit.
    That close to the star the tidal effects should be large accelerating the planet outward.
    Not sure about stable, but I was assuming an outward crawl for the inner planet.
    Reply With Quote  
     

  10. #9  
    Moderator Moderator Janus's Avatar
    Join Date
    Jun 2007
    Posts
    2,070
    Quote Originally Posted by PetTastic
    I was just thinking about tidal forces from the star on the planet. In the same way the tidal forces of the earth on the moon are pushing the moon into a higher orbit.
    That close to the star the tidal effects should be large accelerating the planet outward.
    Not sure about stable, but I was assuming an outward crawl for the inner planet.
    It is the tidal forces of the Moon on the Earth that is pushing the Moon away, not vice-versa . The Moon raises tidal bulges on the Earth and it is the friction between the bulges and the Earth cause the transfer of angular momentum from Earth to Moon.

    With the planet/star, it would be the tidal forces of the planet acting on the Star. A star, being a gaseous body, will produce a smaller amount of drag between the rotating star and the tidal bulges. I would expect an transfer of angular momentum from star to planet to be fairly slow.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


    Edit/Delete Message
    Reply With Quote  
     

  11. #10  
    Suspended
    Join Date
    Aug 2010
    Posts
    179
    This new astronomical discovery is possibly one of the most important of recent years, with the system being remarkably similar to our own solar system, and if the system is indeed made up of seven separate exo-planets it would make it the highest tally of alien worlds ever spotted around a single star.

    http://hicexsistoeverto.wordpress.co...em-discovered/
    Reply With Quote  
     

  12. #11  
    Forum Bachelors Degree PetTastic's Avatar
    Join Date
    Jul 2010
    Location
    London UK
    Posts
    421
    Quote Originally Posted by Janus
    With the planet/star, it would be the tidal forces of the planet acting on the Star. A star, being a gaseous body, will produce a smaller amount of drag between the rotating star and the tidal bulges. I would expect an transfer of angular momentum from star to planet to be fairly slow.
    I have seen some papers that indicated the opposite (Will post links when I can find them)

    As far as I remember it goes like this:
    Consider a point on the surface of the star that is rotating under the planet. That point is pulled upward towards the planet as it travels under it.
    The peak force being as it travels directly under the planet, but the highest point is reach after that time.
    This puts the bulge in front of the planet as it orbits, gravity from this bulge then pulls the planet faster in its orbit, so it moves outwards.

    The softer the object the bigger the bulge, but in the case of stars the 'friction' comes from moving enormous masses of charged matter through extremely strong magnetic fields distorting them.
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •