Thursday, February 23, 2012
Not Kevin Costner's Water World (in Celestia)
I'm still continually amazed about what we find out about extrasolar planets, I know I shouldn't be, but I am.
Just finding these worlds is amazing enough, but for a couple of these worlds we know what's in their atmospheres. For a Neptune sized world 40 light years from us, GJ 1214b, it looks like it's a water world.
Weeellll sort a water world, according to a recently released paper, it's a hellish steam bath world, with perhaps 50% of it's atmosphere water vapour at a temperature of 230° Celsius (but see this paper as well, which is more suggestive of haze). The rest of the atmosphere is more likely hydrogen and helium. Of course, more onservation is needed, but it's amazing to think we can glimpse what this world is like from fleeting dips in a stars light.
Hubble press release here, and thoughtful commentary by the Bad Astronomer. Once again I've made Celestia files for the system. One for the star (which isn't in the default files) and one for the planet.
As usual, copy the data here to plain text files (GJ1214.stc and GJ1214b.ssc), copy both of the files to the Celestia extras folder. The star is around 950 lightyears away in Lyra, so in the Celestia star browser, you will have to show around 500 stars to see Kepler-20 in the list.
I'll have to update my Celestia Exoplanet Tour as well.
Distance 40 # light years from published data
"b" "GJ 1214"
# Neptune like world
# All data from original papers or URL
Mass 6.55 # M.sin(i) = 6.55 Earth
Radius 17080.284 # 2.678 Earth radi, from URL
ArgOfPericenter 267 #guess
# likely to be in captured synchronous rotation
AltSurface "limit of knowledge" "GJ 1214/b"