Astroblog: HD 69830's planets in Celestia

Sunday, May 28, 2006

HD 69830's planets in Celestia

(Celestia image file of HD 69830 with planets b, c and d in orbit)
If you haven't read Stuart's post on the recent discovery of three Neptune size exoplanets, go over there now. I've made a Celestia file for this solar system (minus the asteroid belt we know is around it). You can download the SSC file here. Note that Version 1.4 of Celestia uses different image file descriptions for several planets and asteroids compared to the early versions. All my previous files were set up for early version, so UB313 and the new Plutonian moons etc come out as blank spheres. I've fixed Sylvia and the Plutonian Moons, I'll work my way through the others eventually (the old versions can be found here and here for people running Celestia 1.1-1.3).

(Image Credit ESO [click to enlarge]) Anyway, back to the planets. This image is an "artistic rendering" from the ESO. Note that the images of the planets are greatly exaggerated in size compared to their actually sizes from the point of view (the Celestia image shows the correct observed sizes from a given vantage point). The size and density of the asteroid belt is also exaggerated. But hey, the point of these things is to capture peoples imaginations. The ESO site also has a nice press release on the planets, as well as some cool animations.

(Image Credit ESO [click to enlarge]) People are really excited as at least one of these planets is in the putative habitable zone of liquid water. While they are not Earth-like in any real sense, they are the first good evidence that non-Jovian planets can end up in solar system type orbits. However, they may much up our understanding of how planets form. The hot superjovians completely messed up our first models, there was no way we could see that jovian planets could from so close to a sun. Now we have a migration model, where Large planets form far out from the star, and migrate in. These planets are thought to have migrated in after forming, but at least two have to migrate through the asteroid belt. While they won't have as big an effect as Jovians, I have a hard time understanding how migrating Neptunian worlds will leave a susbtantial asteroid belt (Stuart, Megan any ideas?).

# posted by Ian Musgrave @ 9:17 am