World With Triple Sunsets

[kingwinner]

"NASA Scientist Finds World With Triple Sunsets"

http://www.nasa.gov/vision/universe/newworlds/threesun-071305a.html

 

I have read an article on the NASA web site! It is very interesting! :lol: However, I don't totally understand what it is saying in detail, prehaps lacking the background in astronomy and cosmology. :hihi: Here are some of my questions that I hope somebody who has read the article can answer:

 

"The new planet belongs to a common class of extrasolar planets called "hot Jupiters," which are gas giants that zip closely around their parent stars. In this case, the planet whips every 3.3 days around a star that is circled every 25.7 years by a pirouetting pair of stars locked in a 156-day orbit. "

What is the 156-day orbit referring? The star-pair orbiting around the parent star? The planet orbiting around the parent star? or...? Also, is it really possible to have 2 "suns" orbiting around another "big sun", won't they be called planets because they orbit a star? And is it possible for the 2 "suns" to stick together and kind of like orbiting around each other, as the animation in the web site shows?

 

"Previously, astronomers had identified planets around about 20 binary stars and one set of triple stars. But the stars in those systems had a lot of space between them. Most multiple-star arrangements are crowded together and difficult to study."

Isn't this HD 188753 the first triple-star system with a planet? Why it says here that one set of triple stars with identified planet has already been found previously? On the top of the article it says "The new planet, called HD 188753 Ab, is the first known to reside in a classic triple-star system."

 

"Hot Jupiters are believed to form out of thick disks, or "doughnuts," of material that swirl around the outer fringes of young stars. The disk material clumps together to form a solid core, then pulls gas onto it. Eventually, the gas giant drifts inward. The discovery of a world under three suns contradicts this scenario. HD 188753 would have sported a truncated disk in its youth, due to the disruptive presence of its stellar companions. That leaves no room for HD 188753's planet to form, and raises a host of new questions."

How does this discovery of a triple-star system with a planet contradicts the former theory of hot jupiters formation?

 

Does anyone know any web site which provides some background information related to this topic? I would be eager to learn more! :)

[Jay-qu]

the 156 day orbit would be the time that it takes for the two stars in orbit around the parent star to orbit each other, they orbit a common centre of mass - a point between the centers of the two stars depending on the relative masses of them.

[kingwinner]

the 156 day orbit would be the time that it takes for the two stars in orbit around the parent star to orbit each other, they orbit a common centre of mass - a point between the centers of the two stars depending on the relative masses of them.

I see!...how is defined to be a complete orbit in this case? (156 days) the 2 stars are both orbiting around each other...

 

Isn't a star always the CENTER of a system? Why the 2 stars pair together and orbit around a "big sun" just like what planets usually do?

[cwes99_03]

You need to read about Kepler's laws. Orbitals are in fact not circular, but eliptical. They are eliptical because both objects contain mass. Thismeans that there has to be a focal point. The earth actually orbits the sun in an elipse that is very nearly circular, I'm told Venus even more circular.

 

Binary star systems as the one described here, orbit a central point, much like a pair of figure skaters spinning in a large circle. The larger of the pair orbits closer to the center of the ring while the smaller of the pair orbits further out. One can still make a measure of how long it takes for each person to make an orbit around that center of mass, but low and behold the second partner orbits in the same amount of time because they remain in lock-step around that center of mass.

 

So we have a binary star system, paired with a hot jupiter-star system. Fairly common scenario in the cosmos. There are a lot of binary-binary systems out there. I know of one in particular near the northern star polaris.

[kingwinner]

You need to read about Kepler's laws. Orbitals are in fact not circular, but eliptical. They are eliptical because both objects contain mass. Thismeans that there has to be a focal point. The earth actually orbits the sun in an elipse that is very nearly circular, I'm told Venus even more circular.

 

Binary star systems as the one described here, orbit a central point, much like a pair of figure skaters spinning in a large circle. The larger of the pair orbits closer to the center of the ring while the smaller of the pair orbits further out. One can still make a measure of how long it takes for each person to make an orbit around that center of mass, but low and behold the second partner orbits in the same amount of time because they remain in lock-step around that center of mass.

 

So we have a binary star system, paired with a hot jupiter-star system. Fairly common scenario in the cosmos. There are a lot of binary-binary systems out there. I know of one in particular near the northern star polaris.

Then why it says "The new planet, called HD 188753 Ab, is the first known to reside in a classic triple-star system" while later it says "Previously, astronomers had identified planets around about 20 binary stars and one set of triple stars"

 

So is this the first known system to have a planet within a triple-star system, as the article states?

 

Even worse, the Wikipedia says "This star system is only the second triple-star system known to have a planet orbiting it "

http://en.wikipedia.org/wiki/HD_188753

 

Why do they contradict each other? :hihi: I must manage this because I have to do a report on it...

[ldsoftwaresteve]

I read that Immanual Velikovsky posited Saturn was once a star and that it and our sun formed a binary star system. The theory, which was never published by I.V. stated that Saturn went Nova and is the origin of not only the genesis in the bible but the cause of the legend of the great flood.

I like ideas that drive home the idea that the universe is a wild and untamed place.

[Bo]

I completely agree with the basic thought behind Velikovski's ideas (myths and legends have an origin in the physical world). Unfortunately, in my opinion, his scientiffic ideas lack any basis. (for the idea you gave, the first argument that comes to my mind is that if our solar system was binary, it would never become so immensely regular.)

 

Bo

[ldsoftwaresteve]

I completely agree with the basic thought behind Velikovski's ideas (myths and legends have an origin in the physical world). Unfortunately, in my opinion, his scientiffic ideas lack any basis. (for the idea you gave, the first argument that comes to my mind is that if our solar system was binary, it would never become so immensely regular.)

 

Bo

Okay, I'm not going to try to argue his position. I did, however, think that particlar solution to the genesis was pretty slick. He never published that particular idea probably because he hadn't found enough substantial proof that it was true. I recount it third hand.

 

Some of his published ideas were pretty interesting and some predictions he made were quite good so I don't know why you would say they lack any scientific basis. Perhaps you haven't read his work.

 

If I recall correctly, he predicted that all planetary bodies have an electric charge (prior to the discovery of the van allen belts), that Jupiter would emit radiation like a star and that the earth has had a very violent history. He also predicted that Venus would be a lot hotter than anyone would believe, which is something that has definitely turned out to be true.

 

At the time his ideas came out the 'view' of our solar system was that it was like one big clock ticking away and that change took place gradually over long periods of time, and that the earth was basically a nice safe place. The nature of the ridicule that he endured was because he proposed our home, the earth sun and other planets were not as calm and stable as we'd been led to believe.

 

He used what the ancients documented as his starting point for investigation but he did back up his claims with scientific investigation.

 

We can only guess at what actually happened in the past. It would be great to know for sure but we probably never will. We do tend to treat the written history of humankind with very little or no respect.

[kingwinner]

Then why it says "The new planet, called HD 188753 Ab, is the first known to reside in a classic triple-star system" while later it says "Previously, astronomers had identified planets around about 20 binary stars and one set of triple stars"

 

So is this the first known system to have a planet within a triple-star system, as the article states?

 

Even worse, the Wikipedia says "This star system is only the second triple-star system known to have a planet orbiting it "

http://en.wikipedia.org/wiki/HD_188753

 

Why do they contradict each other? :hihi: I must manage this because I have to do a report on it...

I am completely mixed up now!

So is the HD 188753 the first triple-star system with a planet? Does anyone know and would like to share your knowledge? :lol:

 

I have found 2 different articles discussing the same issue, but they both refer HD 188753 as the first triple-star system that has a planet in it.

 

"It is the first extrasolar planet found in a system with three stars"

http://www.space.com/scienceastronomy/050713_triple_sun.html

 

"First Planet Under Three Suns Is Discovered"

http://pr.caltech.edu/media/Press_Releases/PR12716.html

 

I am just puzzled!