UNSW Astronomers have found a hot bloated planet, twice as big as Jupiter, which is circling its star in a rare polar orbit – a find that raises questions about how planets form.
Riff-in-Thyme said:
UNSW Astronomers have found a hot bloated planet, twice as big as Jupiter, which is circling its star in a rare polar orbit – a find that raises questions about how planets form.
yeah, i read that a few days ago, weird
polar orbit
wonder how it formed?
CrazyNeutrino said:
Riff-in-Thyme said:
UNSW Astronomers have found a hot bloated planet, twice as big as Jupiter, which is circling its star in a rare polar orbit – a find that raises questions about how planets form.
yeah, i read that a few days ago, weird
polar orbit
wonder how it formed?
re-collection of matter ejected from the poles during formation of the star?
Riff-in-Thyme said:
CrazyNeutrino said:
Riff-in-Thyme said:
UNSW Astronomers have found a hot bloated planet, twice as big as Jupiter, which is circling its star in a rare polar orbit – a find that raises questions about how planets form.
yeah, i read that a few days ago, weird
polar orbit
wonder how it formed?
re-collection of matter ejected from the poles during formation of the star?
I wonder if its got anything to do with magnetic patterns?
the abc link has more info. you need to pay for the full article at astrophysical journal.
ChrispenEvan said:
the abc link has more info. you need to pay for the full article at astrophysical journal.
can you provide the link please?
oh right, cheers
CrazyNeutrino said:
ChrispenEvan said:
it in the article linked to in the op
maybe its a rogue captured planet?
> twice as big as Jupiter
If it’s twice as big as Jupiter then it’s a star, not a planet. Proxima Centauri is only 1.5 times as big as Jupiter. Brown dwarfs, unless extremely young, are smaller than Jupiter. Planets, unless either extremely young (or having a much higher hydrogen to helium ratio to Jupiter) are all smaller than 1.1 times as big as Jupiter.
The Kepler dataset of candidate planets used to have many candidates bigger than Jupiter, but these are rapidly being removed as more accurate size estimates show them to be stars.
> which is circling its star in a rare polar orbit – a find that raises questions about how planets form.
Our solar system is really quite exceptional in having planets in circular orbits lined up with the Sun’s equator. Far more than 50% of extrasolar planets and binary stars are in strongly elliptic orbits, an eccentricity of 0.3 is typical. I surmise that our solar system formed with a lot more gas and dust than most, and that the energy losses created by frictional and collisional effects with the gas and dust acted to remove energy from the planets until the orbits to a minimum energy state (circular and in plane with the Sun’s equator). Solar systems that formed with much less gas would tend to have elliptic orbits inclined at a relatively steep angle to the star’s ecliptic, as comets do in our solar system.