Backwards orbiting planet found

On 6/8/2011 5:04 PM, Val Kraut wrote:


There has been at least one recent article on Jupiter size wandering planets
being not that rare. Given that premise a star could capture an additional
planet that would be in retrograde. I would imagine the new planet could
also be way out of plane with the rest of the system. Copernicus and Kepler
on a really complicated system with multiple planes for the planets would
really have a good time. Might also make for some really interesting
asteroid groupings ala a three dimensional perturbation model.

Is there any other evidence for planets in that system? knowing which
way they are orbiting and their orbital plane is would be a big help in
figuring out what's going on.

Pat

On 6/8/2011 5:33 PM, wrote:

The standard explanation has been that repeated encounters with a
larger (probably Jovian-class) planet in a more eccentric orbit (or
even a hyperbolic trajectory) may work to reverse the lesser-mass
object's orbit in gradual stages. One recent study however, indicates
that in at some cases, the parent star may 'flip over'.

You would think the tidal forces generated on the planet that went
retrograde (as some call it) would be awfully severe, and might tear it
apart.

Pat

On 6/8/2011 9:21 PM, Wayne Throop wrote:
: Pat
: You would think the tidal forces generated on the planet that went
: retrograde (as some call it) would be awfully severe, and might tear
: it apart.

Why would the direction of orbit compared to the spin of the star matter?

As the article explains, it's generally thought that the star and its
planets coalesce out of the same spinning proto-solar nebula and retain
their direction of orbit in the solar system that forms.
To put it in a very vulgar form, if you flushed the toilet and the water
started spinning down in one direction, but a turd was going around the
bowl in the opposite direction, you would think that is very odd.
Then you'd best contact a really good priest and have him exorcise your
plumbing system, because just like you instinctively knew when you were
a kid, there's something evil living down there that will come up and
kill you if you don't get out of the bathroom within ten seconds after
flushing the toilet. ;-)


Pat

::: You would think the tidal forces generated on the planet that went
::: retrograde (as some call it) would be awfully severe, and might tear
::: it apart.

:: Why would the direction of orbit compared to the spin of the star matter?

: Pat Flannery
: As the article explains, it's generally thought that the star and its
: planets coalesce out of the same spinning proto-solar nebula and
: retain their direction of orbit in the solar system that forms. To
: put it in a very vulgar form, if you flushed the toilet and the water
: started spinning down in one direction, but a turd was going around
: the bowl in the opposite direction, you would think that is very odd.
: Then you'd best contact a really good priest and have him exorcise
: your plumbing system, because just like you instinctively knew when
: you were a kid, there's something evil living down there that will
: come up and kill you if you don't get out of the bathroom within ten
: seconds after flushing the toilet. ;-)

OK. So... why would the direction of the orbit compared to the spin of
the star matter *for* *the* *tidal* *forces*? You said "you'd think the
tidal forces would be awfully severe". What about the situation would
provoke that thought in particular.

On Jun 8, 6:04*pm, "Val Kraut" wrote:
"Pat Flannery" wrote in message

dakotatelephone...

Star rotates one way, it orbits around it the other way:
http://www.physorg.com/news/2011-06-planet-wrong.html

Pat

There has been at least one recent article on Jupiter size wandering planets
being not that rare. Given that premise a star could capture an additional
planet that would be in retrograde. I would imagine the new planet could
also be way out of plane with the rest of the system. Copernicus and Kepler
on a really complicated system with multiple planes for the planets would
really have a good time. Might also make for some really interesting
asteroid groupings ala a three dimensional perturbation model.

* * Val Kraut

Sure thing, captures should be within reason though uncommon, not that
something better than 1e12 wandering/rogue items are in any short
supply. Make that 1e13 wandering items if including everything of
Ceres or larger.

Tyche could be a captured item, as well as our moon seems captured.

http://www.wanttoknow.info/
http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”

On Jun 9, 6:24*am, (Wayne Throop) wrote:

OK. *So... why would the direction of the orbit compared to the spin of
the star matter *for* *the* *tidal* *forces*? *You said "you'd think the
tidal forces would be awfully severe". *What about the situation would
provoke that thought in particular.

If I recall, it's called Conservation of Angular Momentum. If a planet
(or a moon) is orbiting in the same direction that its primary rotates
('prograde'), the tidal forces work together, causing it to move
outwards over time. A good analogy is pitching a baseball: 'winding
up' before a pitch adds to the ball's momentum when you throw it- it
goes further and faster. If it moves AGAINST the primary's rotation
('retrograde'), the tidal forces work against each other, creating
friction, which causes the orbiting body to draw closer, perhaps
eventually impacting the primary.

On Jun 9, 3:29*pm, " wrote:
On Jun 9, 6:24*am, (Wayne Throop) wrote:



OK. *So... why would the direction of the orbit compared to the spin of
the star matter *for* *the* *tidal* *forces*? *You said "you'd think the
tidal forces would be awfully severe". *What about the situation would
provoke that thought in particular.

If I recall, it's called Conservation of Angular Momentum. If a planet
(or a moon) is orbiting in the same direction that its primary rotates
('prograde'), the tidal forces work together, causing it to move
outwards over time. A good analogy is pitching a baseball: 'winding
up' before a pitch adds to the ball's momentum when you throw it- it
goes further and faster. If it moves AGAINST the primary's rotation
('retrograde'), the tidal forces work against each other, creating
friction, which causes the orbiting body to draw closer, perhaps
eventually impacting the primary.

In our system, Triton is probably the best example, being a large
close-in body orbiting retrograde to its primary's rotation; Triton is
moving closer to Neptune and will eventually (millions of years hence)
probably impact the planet.

:: OK. So... why would the direction of the orbit compared to the
:: spin of the star matter *for* *the* *tidal* *forces*? You said
:: "you'd think th= e tidal forces would be awfully severe". What
:: about the situation would provoke that thought in particular.

: "
: If I recall, it's called Conservation of Angular Momentum. If a
: planet (or a moon) is orbiting in the same direction that its primary
: rotates ('prograde'), the tidal forces work together, causing it to
: move outwards over time. A good analogy is pitching a baseball:
: 'winding up' before a pitch adds to the ball's momentum when you throw
: it- it goes further and faster. If it moves AGAINST the primary's
: rotation ('retrograde'), the tidal forces work against each other,
: creating friction, which causes the orbiting body to draw closer,
: perhaps eventually impacting the primary.

So, you're saying the forces at any given time *aren't* more severe,
but before tidal lock, they'd cause the orbiting body to get closer
to the primary, which in turn would make the tidal forces grow rather
than shrink?

So for the case in question, what's the rate at which the orbit
would be decreasing? Any noticeable change in under a billion years?
And *would* it get tidal lock before impacting the primary? How much
angular momentum in the spin vs the orbit?

: "
: In our system, Triton is probably the best example, being a large
: close-in body orbiting retrograde to its primary's rotation; Triton is
: moving closer to Neptune and will eventually (millions of years hence)
: probably impact the planet.

Or become a ring?

However... I can't find an estimate of when that would happen with
a quick google, but I do note that it's been around multiple billions
of years. Why would its remaining lifetime be such a small fraction
of its total lifetime?

On 6/9/2011 5:24 AM, Wayne Throop wrote:



OK. So... why would the direction of the orbit compared to the spin of
the star matter *for* *the* *tidal* *forces*? You said "you'd think the
tidal forces would be awfully severe". What about the situation would
provoke that thought in particular.

I was referring to the theory that the planet had some sort of encounter
with an object so massive that it it not only canceled all of its
orbital speed in one direction, but imparted enough speed in the
opposite direction to get it orbiting that way.

Pat