Largest Known Planet Discovered

Astronomers say they have discovered what appears to be an entirely new kind of planet, an extra-large gas giant unlike any known world in our solar system or beyond.

source

this planet named HAT-P-1 is reputed to be 1.4 times the size of Jupiter and 450 light years from earth, it seems the scientist's are finding quite a lot of new planets in recent years, all we need now is a decent propulsion system so we can go and find if any are populated

Very interesting article.

Might do a little bit of theorising on the problem mentioned myself. Got a few ideas.

There's bound to be plenty more of these planets hanging around, it's just a matter of time before they find some more.

Yep, it's a very interesting planet.

Not sure it's the largest known exosolar planet though.

Yeah... there's been a lot of gas giants, many above 3 Jovian masses.

HOWEVER, this, is 1.4 times LARGER... I didn't quite catch that. That means it's physical dimensions are that big - which is important, because as Gas Giants accumulate mass, their size difference slows down, since matter closer to the core becomes denser.

Just look at Saturn and Jupiter - Saturn weighs only 95.2 Earths, whilst Jupiter weighs some 314.5 Earths... however, Jupiter is only 1.44 times larger than Saturn (so 3.304 times the mass, but only 1.44 times the size). This new planet could have a huge mass then - very, very close to fusionable).

VERY STRANGE:

I continued reading the article, it says that this planet actually has an incredibly LOW density - opposite that Jupiter, and in line with Saturn!

That's really quite astonishing, since gas giants shouldn't form like that. It's almost as if it's core wasn't composed of solid matter.

Scientists are, currently, stumped. The only explanation I can give is that perhaps it formed from natural hydrogen clouds, and there is no solid matter to be present in its core. Then, its proximity to its star might have something to do with it as well. Still, that's just my speculation...

The problem with your hydrogen cloud theory, Yarium, is that the star itself has a high metallicity, higher than the Sun's. So rocky materials should've been very abundant throughout the protoplanetary nebula of the star. But it doesn't completely rule it out, considering that the differentiation process may have been extra efficient there for some reason and all the metals concentrated close to the star. However, given everything being average, it's hard to see that occuring.

Maybe the gas giant suffered an enormous collision in its youth, destroying the forming core and nearly obliterating the planet. Maybe it pulverised the core to dust, and then when the planet managed to regather itself, the core materials were spread throughout the body of the planet. That way, any radioactive materials would be scattered as well. Then for some reason of internal dynamics, the denser rocky materials never managed to reform a core over the life of the planet, but remained roughly as they were after the collision. With the radioactive materials scattered throughout the planet, they heated the planet internally in such a way as to puff it up to its present size.

Maybe it's heat produced through induction from the interaction between the star's and the planet's magnetic fields.....although if that was the case you'd expect all Hot Jupiters to behave in the same way.

If the interior of the planet is being heated via tidal interactions, induction or whatever, maybe they need to take into consideration the role of sound in the heating of the planet. If the interior of the planet is in a lot of motion and there are huge eddy currents in its gases, then they would generate sound waves which would propagate around the body of the planet. Causing shockwaves in the body of the planet would generate heat. The amount of heat generated would be a function of the intensity, wavelength/frequency and interactions between the shockwaves.


So far, there's been 188 extrasolar planets found. The largest is around 10 Jupiter masses (I think, from memory). The smallest is around 5 Earth masses. The oldest planet is in the globular cluster M4 (in Scorpius)..... it's 13 billion years old. Nearly as old as the universe itself. It's in a 100 year orbit around a pulsar/white dwarf binary system (the pulsar captured the original star late in its history..... the planet formed around the wd when it was a single, fully fledged star).



[edit on 16-9-2006 by GhostITM]

[edit on 16-9-2006 by GhostITM]

GhostITM - While your post is highly informative as a whole, I do feel it needs some minor corrections on your last bits of information.

Firstly, 206 extrasolar planets have been detected. You're correct about some having masses around (and slighly above) 10 SM. In fact, some extrasolar planets near 11 masses, but at that point they cross the threshold of becoming a brown dwarf. Though, the lowest mass extrasolar planet is at .02 EM. Oddly enough, this was the very first ESP discovered (almost 15 years ago.) I believe the largest error you made very well could have just been a keyboard faux pas, because the oldest known ESP is just under 13 million years old.

Sorry for throwing in my own abbreviations into the mix. I'm sure you can figure them out.

Thats very interesting.If one were to compare that planet to earth let alone jupiter side by side,the size would be beyond belief.I bet you a single cloud on that planet would be the same size as earth.

Although it is a rather large planet,it is also a gas giant.Such bodies that are not solid in form like our rocky planets find it easy to maintain such an diameter.Id be highly interested once they find a rocky planet the size of jupiter.Iv heard of two rocky planets that were discovered in another start system the size of neptune a uranus also I havnt as of yet heard of any extra-solar planets the size of jupiter.If a rocky planet with the same diameter (or larger) as jupiter was to be discovered,the gravitational pull would be huge.



[edit on 16-9-2006 by southern_Guardian]

I bet you a single cloud on that planet would be the same
size as earth.

That may be so, though you'd most likely have a much
better with Earth sized storms, rather than a single cloud.

For instance Jupiters hreat storm is the size of the Earth.

Originally posted by cmdrkeenkid
GhostITM - While your post is highly informative as a whole, I do feel it needs some minor corrections on your last bits of information.

Firstly, 206 extrasolar planets have been detected. You're correct about some having masses around (and slighly above) 10 SM. In fact, some extrasolar planets near 11 masses, but at that point they cross the threshold of becoming a brown dwarf. Though, the lowest mass extrasolar planet is at .02 EM. Oddly enough, this was the very first ESP discovered (almost 15 years ago.) I believe the largest error you made very well could have just been a keyboard faux pas, because the oldest known ESP is just under 13 million years old.

Sorry for throwing in my own abbreviations into the mix. I'm sure you can figure them out.

Last I had a look at the database there were 188 planets.....although that was a few months ago and they're finding these things like they're turning out cheese. Thanks for the update

Actually, the brown dwarf/planet threshold is 13 Jupiter masses, and I wasn't counting the pulsar planets in my post.....although you are correct there. The last thing I mentioned is not an error. The planet in M4 is 13 billion years old. The white dwarf it orbits (both were captured by the pulsar PSR B1620-26 several billion years ago) is around 13 billion years old and was once a Sun like star. The planet is around 2.5 Jupiter masses and orbits the pair in a 100 year, near circular orbit. Google it and you'll see.

Actually, most of the extrasolar planets are older than 500 million years..... only those still in accretion disks are younger than that.....some are very young (beta Pictoris for example), but most orbit quite stable, old stars. Even epsilon Eridani is 1 billion years old. Stars such as 47 Ursa Majoris and 51 Pegasi are 6.9 to 8 billion years old. Aldebaran (if they still think the planet is there) is nearly 11 billion years old!!! Although it could also be a brown dwarf because it appears to be at least 11 Jupiter masses.....close to the limit.

Sorry to correct you there...... I have a lot of experience in astronomy.....35 years to be exact

Originally posted by southern_Guardian
Thats very interesting.If one were to compare that planet to earth let alone jupiter side by side,the size would be beyond belief.I bet you a single cloud on that planet would be the same size as earth.

Although it is a rather large planet,it is also a gas giant.Such bodies that are not solid in form like our rocky planets find it easy to maintain such an diameter.Id be highly interested once they find a rocky planet the size of jupiter.Iv heard of two rocky planets that were discovered in another start system the size of neptune a uranus also I havnt as of yet heard of any extra-solar planets the size of jupiter.If a rocky planet with the same diameter (or larger) as jupiter was to be discovered,the gravitational pull would be huge.



[edit on 16-9-2006 by southern_Guardian]

I worked it out awhile back on paper but I can't remember the exact figures, however for a terrestrial planet to have Jupiter's mass, the planet would only have to be 3-4 times the diameter of the Earth. Because volume rises as the cube of the radius (or diameter) and density depends on a number of factors apart from the amount of material present, the volume would increase between 27 and 64 times. With gravitational compaction, the "new" Earth would actually surpass Jupiter mass at the upper end of the volume size. The overall density of the planet would be around 10-15gms/cm^3. I think the surface gravity was up around the 10g mark. Actually, there wouldn't be enough rocky material left in the solar nebula to form the planet. Unless the accretion disk was exceptionally rich in metals (materials other than hydrogen and helium), which probably occur around metals rich stars. Most of it would end up in the star and/or flung out into interstellar space. Even if it did form, it'd end up a giant planet as it would retain all of its gases even if it formed in close to the star. It's substantial surface gravity would see to that.

Although the object formed in the final analysis would most likely end up a brown dwarf, given such a large "seed" for a core.



[edit on 17-9-2006 by GhostITM]