New Transiting Extrasolar Planet

Shooter6947 writes "A new transiting extrasolar planet has been announced -- the only other known object that passes between its star and the Earth each orbit, a situation known as a transit, is HD209458b. The new planet, OGLE-TR-56b, is 0.9 times the mass of our own Jupiter and 1.3 times Jupiter's radius. It is the closest-in extrasolar planet yet found, with its year being only 1.2 days! Read about it from a cnn.com article or from the original scientific paper."

Comments

A iron nuclear reaction is impossible

[Anonymous Coward]

Look at the graphs of energy released vs proton number. It is very low, and incredibly steep at the start, peaks at iron, and goes down at the end(near uranium and other very heavy metals). This is why fusion (going from say 1 proton in hydrogen to 2 in helium) creates energy, as well as breaking something big like uranium in chunks also provides energy.

What this means is that any materials south of iron can be fusioned to create energy(though maybe not enough to self-sustain), and any north of iron can be fissioned to create energy, but iron itself is "nuclearly inert" (for lack of a better catch phrase), so it's possible the 'iron planet' is debris of a star, but it could never reach critical mass 'cause it already has.

Re:A iron nuclear reaction is impossible

[Anonymous Coward]

Touche wyldeling, iron can be transmuted, but it would happen only in a environment that already has protons flying around in it. (ie a star still burning hydrogen). A pure iron planet of any size would be in no danger of criticality.

Actually iron is not the most magnetic, some rare earth magnets like molybdenum can be much stronger. I'd say its a coincidence, the atomic properties are to do mainly with the nucleus, whereas the chemical and magnetic properties are more to do with the outer shell of electrons.

Re:A iron nuclear reaction is impossible - Sorta.

[wyldeling]

Actually, iron, and everything above it, is fusible. The issue is that it requires more energy to get them to fuse then is gained by the fusion process. In practice, only one physical process produces enough energy to fuse iron: supernovas. Under those conditions everything above iron is formed. Why do you think we have heavy elements?

Probes surviving in this paradise.

[Christopher Thomas]

The writeup says the planet has 0.9 times Jupiter's mass, and the article says it has a temperature of 3100 F. This probably means it is not a true gas giant (whoopsie), but it is still hot enough to melt silicon and iron, so there's still no solid surface. Imagine a planet of magma. Were it to cool off, it should become a very large rocky object.

As it is, there's nothing to land on, and it's too hot for a ship to survive. And even if it were cool enough to safely land on, the gravity would be too high for human habitation.

Hmm. That paints an interesting picture. A few relatively common substances (like aluminum oxide) should be solid at those temperatures. Depending on their buoyancy relative to other components (mostly silicates), you might end up with a solid crust (modulo enough convection churn to make the San Andreas fault look like a nice picnic spot). This of course assumes that enough oxygen was bound into oxides in the first place, instead of mostly being bound as water and being stripped early in the planet's life/blown away to the outer system during accretion.

As for dropping probes into that ocean, an aluminum oxide shell should work quite well. Tungsten carbide-coated graphite might work too, being even more temperature-resistant, as long as it doesn't alloy with the surface material. It would be neat to try, though I doubt we'll get a chance any time soon :).

How would you set up the electronics/instruments on the probe, though? Diamond semiconductors, carbon or tungsten wires, aluminum oxide optics? It's an interesting thought experiment.