APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

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APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by APOD Robot » Tue Sep 20, 2011 4:06 am

Image Kepler 16b: A Planet with Two Suns

Explanation: If you stay up long enough, you can watch both suns set. Such might be a common adage from beings floating in the atmosphere of Kepler 16b, a planet recently discovered by the space-based Kepler satellite. The above animated video shows how the planetary system might look to a visiting spaceship. Although multiple star systems are quite common, this is the first known to have a planet. Because our Earth is in the orbital plane of both stars and the planet, each body is seen to eclipse the others at different times, producing noticeable drop offs in the amount of light seen. The frequent eclipses have given Kepler 16b the most accurate mass and radius determination for a planet outside our Solar System. To find a planet like Saturn in an orbit like Venus -- so close to its binary star parents -- was a surprise and will surely become a focus of research.

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by bystander » Tue Sep 20, 2011 4:34 am

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by tnzkka » Tue Sep 20, 2011 8:25 am

Where is the centre of the orbit of this planet in the movie?
The planet seems to remain always at the viewers side of the yellow sun!
Yes, I think I know where it should be, (at the centre of gravity of the two suns) that is the inducement of my question.

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by Phansigar » Tue Sep 20, 2011 11:26 am

The planet appears to orbit the yellow star only. In the video it appears to pass in front of the smaller orange star. Earlier reports had 16b orbiting both stars. Which is correct?

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by rstevenson » Tue Sep 20, 2011 11:39 am

The video clearly shows the planet orbiting both stars, though there is an ambiguous moment as the point of view zooms away from the planet. Have another look.

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by orin stepanek » Tue Sep 20, 2011 12:06 pm

This would make interesting sunsets! 8-)
Click to play embedded YouTube video.
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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by tnzkka » Tue Sep 20, 2011 1:43 pm

rstevenson wrote:
The video clearly shows the planet orbiting both stars, though there is an ambiguous moment as the point of view zooms away from the planet. Have another look.
I beg to differ: From 0" until 23" (movie-time) observer and planet are clearly this ( = the same) side of the yellow sun. Near the end of the movie the planet could/seems to move further from the observer (and behind the yellow sun) but that is left very openended.

Edit/addition: NASA's movie especailly the part perpendicular to the planets orbital plane is much clearer, but I can't translate that movement tot the APOD movie. (My fault perhaps)

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by Uniblogger » Tue Sep 20, 2011 3:16 pm

When learning programming, for fun, I wrote a program using celestial mechanic formulas. It allowed you to select the mass of a sun, place a planet in orbit around it and then watch the results. It would show the orbital path over many ‘years’ and how the temperature would vary as the planet moved around the sun. More often than not, the planet would get into an extended elliptical orbit, become extremely hot and cold, and eventually be flung completely out of the solar system.

However, when I tryed the program with two suns, orbiting around each other in a binary system, I found that getting a stable planet orbit was immensely more difficult. The planet would quickly become too close to one of the stars and get whipped out into infinity between the gravitational slingshot of the two masses.

Since there are many binary systems out there, I believe that the chances of them having planets, let alone habitable ones, are a lot less than any system with a single sun.

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by neufer » Tue Sep 20, 2011 4:31 pm

Uniblogger wrote:
When learning programming, for fun, I wrote a program using celestial mechanic formulas. It allowed you to select the mass of a sun, place a planet in orbit around it and then watch the results. It would show the orbital path over many ‘years’ and how the temperature would vary as the planet moved around the sun. More often than not, the planet would get into an extended elliptical orbit, become extremely hot and cold, and eventually be flung completely out of the solar system.

However, when I tried the program with two suns, orbiting around each other in a binary system, I found that getting a stable planet orbit was immensely more difficult. The planet would quickly become too close to one of the stars and get whipped out into infinity between the gravitational slingshot of the two masses.

Since there are many binary systems out there, I believe that the chances of them having planets, let alone habitable ones, are a lot less than any system with a single sun.
Probably true.

Hopefully, Kepler may be able to give us more statistics on this.

4 Vesta's 1325.15 day orbital period is just
shy of a 1333.1 day 13/4 resonance with Jupiter
(& avoids the 1444.2 day 3/1 Kirkwood gap resonance :arrow: ).

Kepler 16b's 228.78 day orbital period is just
past a 225.94 day 2/11 resonance with Kepler 16.
(Kepler 16b's orbit is also extremely circular to begin with.)
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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by JohnD » Tue Sep 20, 2011 5:50 pm

There have been several Kepler threads running elsewhere on the Asterisk for some time.

On one, I asked the same Q as uniblogger, and Chris Peterson answered, "All real-world systems with more than two bodies are chaotic. That includes our own Solar System. But "chaotic" doesn't mean that a system can't be essentially stable over a very long time, and there are lots of simulations of binary star planetary systems that show this kind of stability. The simplest is just to have the two stars close together, and the orbiting planet very far away from them."

See: http://asterisk.apod.com/viewtopic.php? ... 77#p157777
and the Asterisk Cafe thread entitled "Kepler"

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by Ann » Wed Sep 21, 2011 1:10 am

As I was reading this, I was reminded not so much about the Tatooine planet from Star Wars as about a 1964 book that I own, Beyond the Solar System, written by Willy Ley, partly illustrated by Chesley Bonestell, and with a foreword by Wernher von Braun.

The book is about man's conquest of space beyond the solar system, and much of it deals with how we are going to be able to send a manned spacecraft to Alpha Centauri. (Willy Ley made the bold prediction that the first manned spacecraft bound for Alpha Centauri would leave the Earth so that people who were alive when he was writing this book would get to see the spaceship take off, "say, half a century from now". Since he wrote that in 1964, we only have three years left to make his prediction come true.)

Willy Ley devoted much of his book to the discussion of Alpha Centauri. He talked about the fact that Alpha Centauri is a binary star and wrote this about the prospect of either component having planets:
Since Component A is just like our sun and Component B at least similar to our sun, it can be expected that both, but certainly component A, have planets.
I scoffed when I first read this, but Willy Ley may be right in a way that I wasn't thinking about when I read it back then. It could be that almost all suns are born with planets of some kind, since they form out of rotating accretion disks which are likely to form clumps that grow into some form of planets. On the other hand, it could be that some stars are likely to lose most, and possibly all, of its planets, most likely due to interaction with other stars.

Willy Ley discussed the orbits of the planets of the binary Alpha Centauri system. He noted that the separation of the A and B components of Alpha Centauri varied between the Sun-Saturn distance and the Sun-Neptune distance, and he discussed the possiblility of planets moving in a figure 8-shaped orbit around both stars. Ley rejected the figure 8-shaped orbit since it could probably not be stable. But he added:
If the two components [of Alpha Centauri] were even closer together, about 1 A.U. apart or less, the orbits of their planets would most likely be around the binary as a whole, as if there were only one mass at the center.
There you have it! Willy Ley described Kepler 16b back in 1964!

Kepler 16b is not so much the Tatooine planet as it is the Willy Ley planet!

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by islader2 » Wed Sep 21, 2011 1:59 am

If the correct caption for this APOD had been "A Planet with Two Stars"==Please let us not go there into an English language quagmire==I would give it FIVE stars! What a grand astro-confiirmation! Congrats, Kepler team. Thanx. :D :)

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Willy Ley

Post by neufer » Wed Sep 21, 2011 2:10 am

http://www.astronautix.com/astros/ley.htm wrote:
Image
<<Ley, Willy (October 2, 1906 - June 24, 1969) German-American writer, extremely effective populariser of the idea of space flight - first in Germany and then in the United States.

Willy Ley was an extremely effective populariser of the idea of space flight - first in Germany and then in the United States. Ley was born in Berlin. Fluent in German, English, Italian, French, and Russian, he studied astronomy, physics, zoology, and paleontology at the University of Berlin. He finally settled on journalism and received his degree from the University of Koenigsberg. Becoming fascinated by the idea of manned space travel as the result of Oberth's books, he was a founding member of the VfR (Society for Spaceship Travel) in 1927. He published several books promoting spaceflight as well as editing the VfR's journal, Die Rakete. Finding the Nazi regime not to his liking, and the opportunity for further private rocket development barred, Ley left Germany in 1935.

In America, he immediately began participating in further rocket experiments with the American Rocket Society, but found that the American public believed the idea of rocket flight was science fiction. So Ley wrote articles and books that dealt with the potential of rocket technology to achieve manned spaceflight within the lifetime of the readers. He was able to explain the basic physics and principles of space travel and rocket technology with unusual clarity and simplicity. He became an American citizen in 1944, and at the same time published one of his most influential works - Rockets: the Future of Travel Beyond the Stratosphere. This went through numerous updates, the final version being Rockets Missiles and Men in Space in 1968. Ley was involved with the most significant efforts to poularise spaceflight in the 1950's: the Collier's magazine and subsequent book series that portrayed man's conquest of space as illustrated by Chesely Bonestell; and the Walt Disney Tomorrowland television series. Ley was everywhere, churning out articles for science fiction and mass market magazines; serving as technical advisor for the Tom Corbett, Space Cadet television series; and designing passenger rockets for plastic model companies. Ley was also one of the leading writers of popular science and science history books, including marvelous accounts of the history of paleontology, astronomy (Watchers of the Skies, and cryptozoology.

Having done more than anyone to convince the American public of the potential for manned spaceflight, Ley died just weeks before the Apollo landing on the moon in 1969. He was survived by his wife, Olga. Generations of his readers were motivated to enter careers not just in rocketry, but in many other fields of science as well.>>
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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by DavidLeodis » Wed Sep 21, 2011 10:59 am

Great image brought up through the "surprise" link. Now that is what I call a computer! It even has a wheel. Much more fun than the 'it's small enough to fit into your pocket' ones. :)

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by JohnD » Wed Sep 21, 2011 4:33 pm

So that's Willy Ley!

A people say that Peter Sellers modelled Dr.Strangelove on Wehrner Von Braun!

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else rotwang: strangelove

Post by neufer » Wed Sep 21, 2011 5:19 pm

JohnD wrote:
So that's Willy Ley!

A people say that Peter Sellers modelled Dr.Strangelove on Wehrner Von Braun!
http://en.wikipedia.org/wiki/Dr._Strangelove,_or_How_I_Learned_to_Stop_Worrying_and_Love_the_Bomb wrote:
<<Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, commonly known as Dr. Strangelove, is a 1964 black comedy film which satirized the nuclear scare. It was directed, produced, and co-written by Stanley Kubrick, starred Peter Sellers and George C. Scott, and featured Sterling Hayden, Keenan Wynn, Slim Pickens, and Tracy Reed. The film was loosely based on Peter George's Cold War thriller novel Red Alert, also known as Two Hours to Doom.
Image
  • Rotwang in Lang's Metropolis
Image
The title character, Dr. Strangelove, who was not in the original book, serves as President Muffley's scientific advisor in the War Room, presumably making use of prior expertise as a Nazi physicist. When General Turgidson wonders aloud what kind of name "Strangelove" is, saying to Mr. Staines (Jack Creley) that it is not a Kraut name, Staines responds that Strangelove's original German surname was "Merkwürdigliebe," without mentioning that "Merkwürdigliebe" translates to "Strangelove" in English. Twice in the film, Strangelove 'accidentally' addresses the President as "Mein Führer."

The character is an amalgamation of RAND Corporation strategist Herman Kahn, mathematician and Manhattan Project principal John von Neumann, German rocket scientist Wernher von Braun and Edward Teller, the "father of the hydrogen bomb." There is a common misconception that the character was based on Henry Kissinger, but Kubrick and Sellers denied this. Kissinger was not a presidential adviser until 1969. The wheelchair-using Strangelove furthers a Kubrick trope of the menacing, seated antagonist, first depicted in Lolita through the character "Dr. Zaempf." Strangelove's accent was influenced by that of Austrian-American photographer Weegee, who worked for Kubrick as a special photographic effects consultant. Strangelove's appearance echoes the mad scientist archetype as seen in the character Rotwang in Fritz Lang's 1927 film Metropolis. Sellers's Strangelove takes from Rotwang the single black gloved hand (which in Rotwang's case is mechanical because of a lab accident), the wild hair and, most importantly, his inability to be completely controlled by political power. According to film critic Alexander Walker, Sellers improvised Dr. Strangelove's lapse into the Nazi salute, borrowing one of Kubrick's black leather gloves for the uncontrollable hand that makes the gesture. Dr. Strangelove apparently suffers from diagonistic apraxia, or alien hand syndrome. Kubrick wore the gloves on the set to avoid being burned when handling hot lights, and Sellers, recognizing the potential connection to Lang's work, found them to be menacing.>>
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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by zbvhs » Fri Sep 23, 2011 2:19 pm

The Sun and its planets actually orbit the center of mass or barycenter of the solar system. This is why the Sun's astronomical position seen from afar would display a slight wobble due to the presence of the planets. In the case of the Kepler system, the barycenter is probably somewhere between the two stars and would move around some due to the motion of the planet. The planet likewise would orbit the barycenter but I don't see how it could have a perfectly circular orbit. The Kepler system is a classic n-body system or in this case, a 3-body system. Is this how it's modeled for orbit determination?

This is interesting because astronomers are tracking the orbits of stars at the center of the galaxy and are assuming that the stars are orbiting a massive black hole. But is this necessarily so? Couldn't the stars also be orbiting a point in space that is the galaxy's center of mass or barycenter?
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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by neufer » Fri Sep 23, 2011 2:38 pm

zbvhs wrote:
The Sun and its planets actually orbit the center of mass or barycenter of the solar system. This is why the Sun's astronomical position seen from afar would display a slight wobble due to the presence of the planets. In the case of the Kepler system, the barycenter is probably somewhere between the two stars and would move around some due to the motion of the planet. The planet likewise would orbit the barycenter but I don't see how it could have a perfectly circular orbit. The Kepler system is a classic n-body system or in this case, a 3-body system. Is this how it's modeled for orbit determination?

This is interesting because astronomers are tracking the orbits of stars at the center of the galaxy and are assuming that the stars are orbiting a massive black hole. But is this necessarily so? Couldn't the stars also be orbiting a point in space that is the galaxy's center of mass or barycenter?
  • 1) The stars are orbiting a point in space that is the center of mass or barycenter of the mass INSIDE the orbit of those stars.

    2) That barycenter of the mass is dominated by the massive black hole.

    3) That barycenter of the mass may also be in dynamic motion but such motions are relatively slow compared with the observed orbits.
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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by JohnD » Fri Sep 23, 2011 3:35 pm

I'm sure the barycentre idea is right, and will be realtively constant, when considering two bodies - vz Earth and Moon. But the effect will not be constant on Kepler-16b, any more than the effect of the Sun and Moon is constant on the oceans of the Earth. The attraction will vary according to the orientation of the three bodies.

John

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by jimr63 » Thu Oct 06, 2011 2:33 am

Sorry, but Kepler 16b is pretty dull for us very curious non-astronomers. Why not rename it "Tatooine"?

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by GaryR » Sat Oct 08, 2011 1:35 am

jimr63 wrote:Sorry, but Kepler 16b is pretty dull for us very curious non-astronomers. Why not rename it "Tatooine"?
You could try suggesting it to the IAU (International Astronomical Union), the governing body for naming celestial objects? They might adopt it, unless it is copyrighted by George Lucas! :roll:

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Re: APOD: Kepler 16b: A Planet with Two Suns (2011 Sep 20)

Post by neufer » Fri Apr 11, 2014 1:49 pm

Click to play embedded YouTube video.
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