What's the difference between a 2:1 and a 4:2 resonance? I mean, when a moon has made two orbits and the other one four orbits, the moons must also be alliged at the starting position after the outermost moon has made one orbit.

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

It is a different type of resonance.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

That's not much of an explanation. I've never heard of a 4:2 resonance, per se.

My SSD book says that the 4:2 Mimas-Tethys resonance is unusual because it's a "second order resonance" (the only one known in the solar system). I'm not entirely sure what that means, beyond the fact that SSD says such a resonance can involve the inclination as well as the eccentricities of the satellites. And also the "conjunction of the two satellites librates about the midpoint of the nodes".

Either way, it's something different from a 2:1 resonance (which is a "first order resonance").

Right, I don't know it any better, thus the short explanation.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Wikipedia wasn't much help. It also refers to the nodes "The point of conjunctions librates around the midpoint between the nodes of the two moons". This isn't very clear because each moon has two nodes (an ascending one and a descending one) so there are four points between which you could potentially construct six lines. It also includes the following equation, but omits to define capital omega (n is the satellite's mean angular motion).

The diagram in the orbital node page may have the answer:


There Ω is the longitude of the ascending node (☊)

(First link doesn't work AFAIK)

I don't really get it by now, but please let me know if any of you figure it out.

But funny you actually pretended as you know what it was

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

In Bayesian analysis of the radial velocities of HD 11506 reveals another planetary companion the discovery of a new planet HD 11506c by a new analysis of previously published radial velocity data. Previously HD 11506 had been thought to have one companion, a ≥4.85 M_J planet in a 1280 day orbit. The new analysis says it has two, a ≥3.44 M_J planet in a 1270 day orbit, and a ≥0.82 M_J planet in a 170 day orbit. The host star is a G0 dwarf.

The low density transiting exoplanet WASP-15b reports the discovery of yet another inflated hot jovian, this one in a 3.75d orbit around an F5 star.

Reanalysis on the radial velocity data of the star HD 11506 reveals another, hotter eccentric Jupiter.

A hot Neptune around HD 16417.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

The freak eccentric planet HD 80606b is a transiting planet! With an 111-day orbit it has by far the longest orbital period compared to other transiting planets.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

It was already known to have secondary transits so the detection of a primary transit was nice but not surprising.

Yes, but the probability of a primary transit was something like 10%. So we were lucky.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

So Kepler is in 'the air'. I have a couple of question about its operation though.

1) Is Kepler currently running tests or is it actually up and running, doing scientific studies already?

2) I know that a planet has to do three orbits before we can say it's a planet, but will it be published when they see the second orbit of the planet, saying 'A possible planet has been found and will be confirmed in another orbit's time'?

3) I know a planet has to do three orbits, but when a group of astronomers see the orbit the third time, how long will it take for the data to be processed and finally published? Is it immidiately (or within a week or so) or will it take months or even years?

4) What is the shortest period for a planet that is within the habital zone? Consider a small star orbited by a planet in the habital zone, say 3 times the period and add the number of days from question 3 (and question 1 if it is not already running) - when can we get the first result for a planet in the habital zone if we found it's first passing of the sun on the very first day for instance?

Hope you get me, or else please say so and i will try and explain it in better details

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

Still running tests. Here is the latest from the Kepler thread in Space Exploration.

__________________
At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

Oh ok thanks, didn't even look if there was a Kepler-dedicated thread started, but i guess i could've told myself

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

A fourth planet in Gliese 581 system. With the mass of only 1.9 M_E it is the smallest found to date using the RV method. The orbit of Gl 581 d has been revised, placing it well within the habitable zone of the star.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

HD 96167 b, another massive eccentric Jupiter.

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

here

The planet's designation is not given.
Presumably the galaxy outside our solar system is the Milky way, but the article doesn't say that for sure.


-----
Ahh, apparently it's in this galaxy:
Lightest exoplanet yet discovered

I see now that Kullat Nunu got the planet's name earlier today.

It is Gliese 581 e. You know, Solar System, Milky Way, what's the difference?

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

What makes a planet a Hot Neptune instead of a Hot Uranus?

No Klingons circling it.

__________________
We want our children to go to the planets. Burt Rutan 6/21/04 K.I.L.L. S.M.U.R.F.S.
Tuckers! Automotive Oddities! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither. MachineCast Save the planet, by leaving it! "To be second in space is to be second in everything," LBJ.

You know, I'm kind of used to people being completely ignorant about astronomy.. what actually bothers me more is this:

It hurts my brain.

__________________

Now we're truly on our final run for the first objective in the exoplanet hunt - to detech an Earth-like exoplanet withit the habital zone. First of several goals leading to the detection of life.

LOL I can only agree with you on this one. I can't recall i've read an article in a newspaper ever that is just correct. Yesterday i read an article about the Herschel Space Observatory saying something along the lines "...the space shuttle will be 4 meters across...'

Note: In Denmark, 'space shuttle' is called 'rumfærge', while 'space ship' is called 'rumskib' and 'space rocket' is called 'rumraket'. I guess they mixed those up, but not sure what they actually wanted to say. Something like "...the space ship will be 4 meters across...' From what i could see they were talking about the outer shell of the telescope, while this would be the best way to say it '...the space telescope will be 4 meters across...'

Some time ago we found back then new record holder in the exoplanet field being the smallest ever found. Close to what Squink quoted, they didn't just say "...galaxy outside our solar system...", but actually wrote "...astronomers have found a new planet in another galaxy 20 light years away..."

Another thing that bothers me is when they say a new exoplanet is found, they always make it sound like finding exoplanets is a rare thing at first, and they in another line of the article writing that it is a new record holder. But you can easily tell that they newer hear about any other exoplanets of less interest.

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

Guess it is the same reason why we talk about hot Jupiters instead of hot Saturns. Neptune is the more massive and more "important" of the two. Or it could be because Uranus is always neglected...

__________________
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Not eating hot pepper would be a start.

Gliese 581 is proving to be a fertile system. We really should rename it.

__________________
There is a growing tendancy to think of Man as a rational, thinking being, which is absurd.- Marvin the Martian.

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

Where have you read this? Fertile is a big word in exoplanet hunting and we can't even say for sure if it is a rocky planet.

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

I just meant that it's producing a lot of planets.

__________________
There is a growing tendancy to think of Man as a rational, thinking being, which is absurd.- Marvin the Martian.

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

Oh sorry, thought you were talking about the planet and not the star. Just didn't notice the lack of an 'e'

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)

Huh.

In first grade, I learned that Uranus and Neptune were "twins" of one another, and ever since then I'd assumed their masses were almost identical. I had no idea until I looked it up, just now, that Neptune was over 2 Earth masses larger than Uranus.

Of course, since the two of them are referred to as "ice giants," it seems kind of funny to talk about a "hot Neptune".

In many aspects they are twins, more twins than any other two planets in our solar system i would say. It is nothing but a conincidence that Neptune is a bit larger than Uranus. However, i've always thought Uranus was the largest

__________________
Have your computer do CHARITY in fields such as medication, physics, chemistry and more without moving a finger.
Visit http://boinc.berkeley.edu/ for more info. Thank you in advance!!!
Please PM me if this signature convinced you to join the great BOINC community.

http://www.boincsynergy.com/images/stats/comb-5873.jpg

"The world is a fine place and worth fighting for." (Ernest Hemmingway)