A Super-Massive Transiting Planet

  • Thread starter doubletruncation
  • Start date
Status
Not open for further replies.
D

doubletruncation

Guest
The last week has had a number of very interesting exo-planet discoveries (particularly Gliese 581 c and the first Corot planet). Another one that came out maybe two days ago or so is the discovery of a transiting super-massive planet (8 times the mass of jupiter) by the HAT network. You can find a short discussion and a link to the paper here: http://oklo.org/?p=208 as well as a discussion on some of the very interesting preliminary modeling of this planet's weather here: http://oklo.org/?p=210 . <br /><br />This planet is actually very interesting in a number of ways. First of all, it's the first transiting planet that's substantially larger than jupiter, although many of these had been known from the radial velocity surveys. Finding a transiting example is very interesting because that gives the density and opens up all the fun follow-up. While the planet has 8 times Jupiter's mass, it's radius is only slightly larger than Jupiter which gives it a density of about 6 grams/cc. This is actually quite reassuring because it's very close to what was predicted for planets this big (jupiter, brown dwarfs and small m-dwarf stars are thought to all have roughly the same diameter) - and in fact theorists were much more confident about the predicted mass/radius relation for these very big planets than they are for jupiter size and smaller planets. <br /><br />The other really interesting thing about this planet is that it has such a high orbital eccentricity, so its insolation changes by something like a factor of 9. That means this planet will almost certainly have some incredible weather - many aspects of which may be detectable with Spitzer. <div class="Discussion_UserSignature"> </div>
 
D

dragon04

Guest
I don't know how extraordinary this is considering the confirmed planets of multile Mj already known.<br /><br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>
 
D

doubletruncation

Guest
The reason why it's interesting is because it's a transiting planet, which means we can now start to learn something about the physical properties of these objects (besides just that they exist). One of the most fundamental predictions for objects in hydrostatic equilibrium is their mass-radius relation. Previously people had measured radii for things about the mass of jupiter (previously the most massive transiting planet known was less than twice the mass of jupiter) and objects about 100 times the mass of jupiter, but there's a whole two orders of magnitude in between that had not been observed and that really marks the transition from stars to planets - for the first time the theory for the structure of objects in this transition can be confronted with observations.<br /><br />The other cool thing about this system is that due to its high eccentricity (about 0.5) it will probably have more extreme weather than any transiting planet known to date and will thus be an excellent candidate for detecting cloud patterns (basically mapping its surface). <div class="Discussion_UserSignature"> </div>
 
Status
Not open for further replies.

Latest posts