NASA confirms discovery of 'Tatooine' planet

Largest crowdsourced astronomy network helps confirm discovery of ‘Tatooine’ planet.

Led by Lehigh University professor Joshua Pepper, team includes nearly 40 members in 10 countries across 4 continents; Measurements by Swarthmore faculty and amateur astronomer in Portugal, helped verify new planet Kepler-1647

This is an artist's impression of the simultaneous stellar eclipse and planetary transit events on Kepler-1647. Such a double eclipse event is known as a syzygy. CREDIT Lynette Cook
This is an artist’s impression of the simultaneous stellar eclipse and planetary transit events on Kepler-1647. Such a double eclipse event is known as a syzygy. CREDIT Lynette Cook

Crowdsourcing is used for everything from raising funds to locating the best burger in town. The practice of enlisting a large group of people to provide a service, information or a contribution to a project–most often via the internet–is a defining feature of our era.

Though the term crowdsourcing was coined in 2005 by Wired Magazine editors to describe how businesses were outsourcing work, one of crowdsourcing’s earliest uses was for science.A plea from Yale science professor Denison Olmsted–published in a newspaper article in 1833–asked the public to send in their observations about a major meteor storm. Olmsted then used the information to make significant advances in our understanding of the nature of such storms.

Now Lehigh University astronomer assistant professor of physics Joshua Pepper is using crowdsourcing to gather observations worldwide–and the information is being used to verify the discovery of new planets. His network– known as the “KELT Follow-Up Network”–is made up of nearly 40 members in 10 countries across 4 continents. The group–the largest, most coordinated network of its kind–contributed key observations to confirm the existence of the recently-identified planet, Kepler-1647 b.

The new planet was discovered by a team at NASA’s Goddard Space Flight Center and San Diego State University used the Kepler Space Telescope. The discovery was announced today in San Diego, at a meeting of the American Astronomical Society. The research has been accepted for publication in the Astrophysical Journal with Veselin Kostov, a NASA Goddard postdoctoral fellow, as lead author.

Planets that orbit two stars are known as circumbinary planets, or sometimes “Tatooine” planets, after Luke Skywalker’s homeland in “Star Wars.” Using NASA’s Kepler telescope, astronomers search for slight dips in brightness that hint a planet might be transiting in front of a star, blocking a small portion of the star’s light.

“But finding circumbinary planets is much harder than finding planets around single stars,” said SDSU astronomer William Welsh, one of the paper’s coauthors. “The transits are not regularly spaced in time and they can vary in duration and even depth.”

To help verify what they had seen, the researchers made use of the worldwide network of professional and amateur astronomers that Pepper–a coauthor on the paper–had created.

“Most members of our network have small telescopes that are not able to observe distant galaxies–but they are very well-suited to observing bright stars, like the ones Kepler-1647 b is orbiting,” said Pepper.

The two network astronomers whose observations helped researchers to estimate the mass of the new planet are Eric L.N. Jensen, professor of astronomy at Swarthmore College and Joao Gregorio, an amateur astronomer in Portugal–both listed as co-authors on the paper.

“It’s really exciting for me to be part of this discovery, since I’ve been working on this problem for a long time, said Professor Jensen. “As a graduate student in the early 1990s, I studied dusty disks around young binary stars. We thought that such disks should form planets, but that was before any planets had been discovered outside the solar system, so it was just speculation at that point. I never thought that one day I would help discover a circumbinary planet.”

“As an amateur being involved in the KELT follow-up network giving my contribution to the discovery of ‘new worlds’ is amazing–I’m very proud to be able to contribute,” said Mr. Gregorio.

Kepler-1647 is 3700 light-years away and approximately 4.4 billion years old, roughly the same age as the Earth. The stars are similar to the Sun, with one slightly larger than our home star and the other slightly smaller. The planet has a mass and radius nearly identical to that of Jupiter, making it the largest transiting circumbinary planet ever found.

“It’s a bit curious that this biggest planet took so long to confirm, since it is easier to find big planets than small ones”, said SDSU astronomer Jerome Orosz, another coauthor on the study. “But it is because its orbital period is so long.”

The planet takes 1,107 days (just over 3 years) to orbit its host stars, the longest period of any confirmed transiting exoplanet found so far. The planet is also much further away from its stars than any other circumbinary planet, breaking with the tendency for circumbinary planets to have close-in orbits. Interestingly, its orbit puts the planet within the so-called habitable zone. Like Jupiter, however, Kepler-1647 b is a gas giant, making the planet unlikely to host life. Yet if the planet has large moons, they could potentially be suitable for life.

“Habitability aside, Kepler-1647 b is important because it is the tip of the iceberg of a theoretically predicted population of large, long-period circumbinary planets”, Welsh said.

The “KELT Follow up Network” was originally assembled to assist Pepper and his colleagues in identifying exoplanets for a project he founded called the Kilodegree Extremely Little Telescope (KELT) survey. It uses two robotic programmable telescopes, one in Arizona calledKELT North and the other in South Africa known as KELT South. The survey has confirmed 15 exoplanets using the transit method. Lehigh, Vanderbilt University and Ohio State run the KELT project together, and the project’s low-resolution telescopes are dwarfed by other telescopes that have apertures of several meters in order to stare at tiny sections of the sky at high resolution. The wide-angle KELT view of the universe, by contrast, comes from a mere 4.5-centimeter aperture with a high-quality digital camera and lens assembly that captures the light of 100,000 stars with each exposure.

“The goal of KELT is to discover more planets that are transiting the brightest stars we can see. In essence, those give us the very rare, very valuable planets,” Pepper says.


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D. J. Hawkins
June 14, 2016 8:51 am

Nifty! I don’t know why, but I had always thought such planets mere affectations of science fiction writers and Hollywood. The universe is endlessly fascinating.

Eustace Cranch
Reply to  D. J. Hawkins
June 14, 2016 9:26 am

A slight aside- Ever notice how planets in much of science fiction are homogenized: “desert planet,” “ice planet,” “jungle planet,” etc.? Just one geology/ecology for the entire planet. Convenient for writers, but unrealistic and frankly lazy.
Oh, and how did ice planets and desert planets- no plant growth- get oxygen atmospheres? Even Frank Herbert didn’t think about that one.

Jeff in Calgary
Reply to  Eustace Cranch
June 14, 2016 11:51 am

You obviously haven’t read many of Herbert’s books. In his books, Dune was once a green paradise. But the introduction of the and worms transformed the planet into the desert wasteland that it was in the first book (Dune). In later books Dune once again becomes green, then when the “God Emperor of Dune” dies, the sand worms are again released, and Dune becomes a desert.

Reply to  Eustace Cranch
June 14, 2016 12:30 pm

O2 won’t last long once the plants stop generating it.
Even without animals to consume it, it will react with just about everything else.

Reply to  Eustace Cranch
June 14, 2016 1:37 pm

the sandworms produced the Oxygen
[??? Are they not over in Dune? .mod]

Reply to  Eustace Cranch
June 14, 2016 5:55 pm

They are usually monocultural and monolingual as well.

Rainer Bensch
Reply to  Eustace Cranch
June 15, 2016 2:42 am

Well, Frank Herbert didn’t know of computers either. At least not in the Dune series.

Reply to  Eustace Cranch
June 15, 2016 5:01 pm

Heh, yes, this is a trope. see TvTropes (Single-Biome Planet)

Tom Halla
June 14, 2016 9:11 am

Interesting post. What the search is finding seems to be an artefact of the search methods, which is biased towards planets that are both large and close.

Reply to  Tom Halla
June 14, 2016 9:25 am

Now if this was about global warming, there would be a lot of models predicting elephants orbiting star systems and it would be all over the press.

D. J. Hawkins
Reply to  Tom Halla
June 14, 2016 10:08 am

It is only a “bias” in the sense that the current search methodology is limited to finding objects both close and large. Previously we could find only single Jupiter-sized objects around nearby stars. Now we can find single earth sized (within a factor of 2 – 3) planets further away. Instrumentation and methods improve with time.

Dodgy Geezer
June 14, 2016 9:25 am

They were looking for Alderan… but all they found was an asteroid field….

Steve M. from TN
Reply to  Dodgy Geezer
June 14, 2016 10:16 am

+1000 LOL

Reply to  Dodgy Geezer
June 14, 2016 11:52 am

I have a ship that can make that run in less than twelve parsecs lol

Joel O'Bryan
Reply to  Dodgy Geezer
June 14, 2016 2:53 pm

I had friends on that Death Star!!

David Schofield
Reply to  Joel O'Bryan
June 14, 2016 2:56 pm

Mr Stevens was my boss.

June 14, 2016 9:45 am

here is something from space not seen before, may be of interest to geologists:
Unknown alien rock found in Swedish quarry

Reply to  vukcevic
June 14, 2016 11:47 am

It’s fossilised dinosaur crap from Uranus…

Reply to  vukcevic
June 14, 2016 12:34 pm

“it is thought to be a splinter of a potato-shaped rock some 20-30 kilometres (12-19 miles) wide, which had smashed into another much larger body, sprinkling our adolescent planet with debris.
With that one sentence, the authors of that article are letting you know that there is no need to read further.
From a single fragment they are able to determine not only the size, but the shape and where the collision occurred 470 million years ago.
Yea right.

Dan Hawkins
Reply to  MarkW
June 14, 2016 3:27 pm

MarkW – I agree with you. In fact the original post is full of that same high level of certainty, as are all reports on “exoplanet” discovery. Surmise is reported as established fact in too many cases.

Mike the Morlock
Reply to  vukcevic
June 14, 2016 6:56 pm

MarkW June 14, 2016 at 12:34 pm
“The object contains very high concentrations (compared to Earth materials), of elements such as iridium, which is very rare on Earth,” Schmitz explained by email.
Careful Mark, think iridium, KT boundary, the stuff forms from impacts of good size. How they came up with the sizes is a relation to the contents of the sample.
We need more info on how they got from “A” to “B”

June 14, 2016 10:11 am

It seem highly unlikely to me that any planet with multiple suns could sustain life . The variations in temperature would be too great .

Reply to  Bob Armstrong
June 14, 2016 11:26 am

I recall a time when it was said that planets around binary systems was impossible. There was a video of a computer simulation (a tip-off to a dubious prediction?) showing the planet eventually being expelled from the system.
As to your suggestion of uninhabitability because of big temperature swings, imagine our solar system with a Jupiter just large enough to be a star. Such a faint star, so far away from Earth, would be unlikely to kill of all of us Earthlings.

Reply to  Bob Shapiro
June 14, 2016 12:19 pm

Jupiter isn’t dense enough to ever become a star, the densest planed is Uranus, it’s the heaviest planet in our solar system. as for life elsewhere why not, intelligence how ever, as the old saying goes lets find some.

Reply to  Bob Shapiro
June 14, 2016 12:22 pm


Reply to  Bob Shapiro
June 14, 2016 12:36 pm

I don’t know anyone who ever said that.
As to stability of this planets orbit, no one has commented on that yet.
The article states that the second star is only a little bit smaller than the primary. So your analogy to a Jupiter sized star is not valid.

Owen in GA
Reply to  Bob Shapiro
June 14, 2016 2:02 pm

Bob Shapiro,
As a computational physics final project problem in my undergrad, I ran a simulation of two Sol-like stars and an Earth-like planet in a system. Most configurations did indeed lead to the hapless planet being flung either out of the system or into one of the two stars, but there were a few general configurations which allowed the planet to survive indefinitely and a much smaller subset that enabled the radiation levels to remain within about 15% of Earth standard. After about 10,000 runs, I found that if the two stars were greater than 10 AU apart, a planet could orbit one of the two stars at 1 AU and stay fairly stable. If they were farther than about 100 AU, the planet didn’t even notice the second star out there. This was the only subset of configurations that were Earth normal. As the stars were moved closer in, the radiation levels would run in a strange spike/drop pattern induced by the planet getting between the two stars then being on the outside with its host star between them. The other pattern that was stable was one in which the two stars orbited each other at about 1 to 4 AU and the planet orbited out beyond 20 AU from the center of gravity. The radiation was too low out there, but if the planet were moved inward, its orbit became more and more erratic and eventually was thrown out before it reached any kind of Goldilocks zone.
I presented the project as a series of movies showing the results in class. I chose about 10 of the most spectacular crashes and two of the best successes and calculated that it actually was not possible in a stable configuration to reproduce the Tatooine sunset as one of the two stars would appear far smaller in the sky unless the distant star was about 5 times the size of the closer one.
Six weeks of computation boiled down to a 5 minute video!

george e. smith
Reply to  Bob Shapiro
June 14, 2016 5:00 pm

Why could there not be a planet with large water oceans like earth, that could orbit about two stars in the stable equilateral triangle configuration ?? Just as happens on earth (highly) variable cloud modulation could maintain a livable Temperature just as happens on earth. I think such a binary star could sustain two such planets opposite each other, so long as the planets are much less massive thsn the smaller of the two stars.
Seems like a stable configuration to me.

Reply to  Bob Shapiro
June 23, 2016 9:16 am

So Owen, you basically were doing a Monte Carlo simulations looking for Lagrangian points. Do you mind telling us what numerical packages you were using and what their properties were, including word sizes?

Reply to  Bob Shapiro
June 23, 2016 9:20 am

@ Sparks, the density data that I can find state that Jupiter’s density is 1.3, which is the same value that they give for Uranus. If we are talking gas giants, Saturn is a bit under 1, Jupiter and Uranus 1.3, and Neptune 1.4. Has that changed? Citations, please.

Reply to  Bob Shapiro
June 23, 2016 9:42 am

Uranus is far from the most massive planet. Not only Jupiter, but Saturn and Neptune are more massive.

Joel O’Bryan
Reply to  Bob Armstrong
June 14, 2016 12:38 pm

The radiation environment around Jupiter was found to be much harsher than expected after the Cassini probe ( on a gravity assist fly-by on its way to Saturn) used its main dish to study the synchnotron radiation given off by relatvistic electrons spiralling along the Jovian planet’s magnetic field lines.
Basically, even Europa gets fried by massive amounts of Beta radiation.
It would only be logical that the 1647 binary sun combination puts out a blasting solar wind that Kepler 1647 b’s magnetic field would accelerate and fry any rocky planet in orbit.

Joel O’Bryan
Reply to  Joel O’Bryan
June 14, 2016 12:39 pm

URL for how our understanding of Jupiters radiation belt underwent a major shift after the 2001 Casini fly-by of Jupiter.

June 14, 2016 10:48 am

I could not see where to send this so dropping it in here for redirection.
Here is an item from Canada’s CBC, think ABC, BBC, Australian rodent named the 1st mammal to go extinct due to human-caused climate change

Retired Engineer Jim
Reply to  nc
June 14, 2016 11:44 am

How many bodies did they find?

Reply to  Retired Engineer Jim
June 14, 2016 12:38 pm


Reply to  nc
June 14, 2016 12:32 pm

Warmunist Hyperbole. I did some research. Numbers had been dwindling for decades, with clear evidence for growing inbreeding. That could have killed them off all by itself, no different than the Isle Royal wolfpack in Lake Superior. The trapping census of 2004 found only 12 animals. There was always danger from storm surge according to the ICRN RED status. Cyclone Monica hit just south in 2006 as a large SS Cat 2. Bramble Cay would have been on the dirty side in the SH. Coild have finished nature’s job. There is no evidence that climate change has yet increased either the number or the intensity of hurricanes and cyclones.
A single declining isolated population extirpated. Probably not extinct as the originating species of which the Cay evolved as an isolated sub apparently exists in the Fly River region of PNG directly opposite the Torres Strait. Big difference between extirpated and extinct. Explained in essay No Bodies. First climate extinction claimed was the golden toad of Costa Rica. Nope, cytridiomycisis disease introduced by national park tourism. Then it was the white lemuroid ringtail possum of Queensland, as declared by Cook University. Nope, white is just a genetic variant; normal color is chocolate brown. Plenty of healthy browns, and some whites since found in one of the two remaining refugia. Now this.

Reply to  nc
June 14, 2016 12:38 pm

More likely it was all those people tramping all over the island and setting out traps that killed off the rodents.
It would be nice if the article would specify how a few inches of sea rise over the last few hundred years would be enough to drown all the rats.

Reply to  nc
June 14, 2016 2:12 pm

What about the snail we humans killed with our CAGW in the Indian Ocean?
Oh yeah, that’s right, they lied about that, too.

Reply to  nc
June 14, 2016 2:24 pm

From your misdirected headline.
“Australian rodent named the 1st mammal to go extinct due to human-caused climate change
Bramble Cay melomys was found only on a tiny island on the Great Barrier Reef”

Opening paragraph reads:
“An Australian rodent found only on a tiny island on the Great Barrier Reef has been declared extinct. Scientists say it’s the first mammal known to be wiped out by human-caused climate change.”
The last paragraph reads:
“However, the report raised the possibility that the species might not be completely extinct. Though it was thought to live only on Bramble Cay and is no longer found there, it or a closely related species might still exist in the Fly River delta of Papua New Gunea, which is thought be where the ancestors of the Bramble Cay population originated.”
That’s how they do climate science, their way.
Besides, it’s still a freakin rat.

Reply to  mikerestin
June 14, 2016 3:16 pm

The rat is extirpated on Bramble Cay. It is not extinct, as other subspecies variants apparently live in PNG directly across Torres Strait. The rat could not have evolved on such a small (12 hectare) single island. It got rafted there from PNG. Makes perfect biological sense. Agree with your comment, for many reasons.

Reply to  mikerestin
June 14, 2016 6:25 pm

… AND now that the rat has been eliminated from the island it (the island) can return to its natural state of eco-blisssustainability – without the unwanted invasive species.
So, rather than a story of blame, the story should one be of reverence and thanks to GAia for coming to the rescue of one of her most precious and vulnerable charges (a tiny island).
100 years of environmental degradation due to rat is now ended, so rejoice, be happy and dance around the ring of stones under the moonlight … or continue to whine and be fearful of the mythic CAGW. It really doesn’t matter which … either action is just as worthy.

george e. smith
Reply to  nc
June 14, 2016 5:13 pm

Well the principal cause of their demise can be discovered by examining the carsases of those critters stashed in the drawers of some zoology research department. The examination required amounts to simply counting the number of samples in those drawers, and the similar drawers of other zoology departments around the globe.
The gathering of samples by “curious” zoologist shas led to the extinction of more than a few species. The Huia might be one good such example.

Reply to  nc
June 23, 2016 9:38 am
June 14, 2016 11:07 am

It’s not Tatooine, otherwise Hollywood would charge you a fee to watch it.

June 14, 2016 11:31 am

I can confirm nasa hasn’t/didn’t discovered Uranus. it’s a fact.

Reply to  Sparks
June 14, 2016 11:36 am

My point is they couldn’t even find Uranus, I don’t know what my point is… shut up!! Uranus (giggles)

Joe Civis
Reply to  Sparks
June 14, 2016 12:50 pm

he he he… you said Uranus….

June 14, 2016 12:22 pm

@sparks, parsecs are distances not durations, since you don’t know that, I’m not sure you have a ship at all.

Reply to  Neillusion
June 14, 2016 12:41 pm

I do have a ship, so there!! just ask my wookie. shut up!

Reply to  Sparks
June 14, 2016 1:08 pm

Sparks is obviously proof that some people just can’t hold their whooshegadsvaroom (a potent cocktail banned in many of the Empire’s provinces). Humans are especially vulnerable because their liver is unable to break down the drink’s complex toxins in a timely manner. Although its physiological effects are seldom fatal it frequently produces behavior that would be typical of an adolescent, for example a fascination with humor (?) focused on reproductive or excretory subjects. This in itself is not necessarily harmful to the individual other than damaging their social standing. Unfortunately for a significant number of people this behavior persists beyond the point of endurance for many other patrons of the establishments where whooshegadsvaroom is sold and provokes acts of violence, often fatal, directed at the intoxicated individual.

Reply to  JustAnOldGuy
June 14, 2016 2:07 pm

To be respectful and not simply tear you a new one, I will simply say this, I enjoy interacting with my enemies just as much as I enjoy hearing from you.
Still, we can live to learn and live to love another day… yeahh! I’ll be myself in a week or two but until then I’ll be sad and blue, I guess I admit I’ll miss you a little bit.

Reply to  Sparks
June 14, 2016 5:58 pm

Stick to Pangalactic Gargleblasters.

June 14, 2016 1:03 pm

Also from NASA
May goes down as Earth’s hottest on record:

Reply to  vukcevic
June 14, 2016 1:52 pm

But the year likely won’t given the looming La Nina. Old farmer saying, Make hay while the sun shines. It won’t be shining on warmunists by yearend

Reply to  vukcevic
June 14, 2016 6:31 pm

I started a fire last night … it was cold in Oregon.

Reply to  DonM
June 14, 2016 7:52 pm

Yeah – and mixed rain and snow is falling outside right now in the foothills of Alberta. Frost warnings.

June 14, 2016 2:05 pm

Maybe I’m just old fashioned… But no one has actually “discovered” any exoplanets. Kepler has provided a ton of evidence that exoplanets are common in our neck of the Milky Way… However, calling these discoveries of exoplanets is like an oil company booking reserves based on an un-drilled bright spot.

Reply to  David Middleton
June 14, 2016 3:28 pm

DM, a very nice analogy.

Smokey (Can't do a thing about wildfires)
Reply to  David Middleton
June 15, 2016 1:35 am

David Middleton, we’ve gone and directly imaged about a dozen of these, so that’s not actually correct. The rest of the “confirmed” exoplanets have had their transit/Doppler signatures re-confirmed multiple times, so again, not actually correct. There still thousands more awaiting such verification, but these are correctly labeled as “candidates,” rather than “confirmed.”
If you simply meant to say that we haven’t
directly seen most of them, you are of course correct, but I don’t, e.g., see a ton of hand-held anemometers measuring the Earth’s jet stream, and no human eye has ever directly (or through a telescope) seen the polar “hexagon” of Saturn. Nevertheless, we’re reasonably sure these things exist thanks largely to remote sensing.
Remote sensing should not to be called into question JUST because it is remote. Question the calibration & verification methods if you like, but even those used to confirm the existence of exoplanets are a lot less suspect now that we HAVE imaged a few of these, and I expect we’ll get much better at it as time goes on.

June 14, 2016 3:07 pm

Here I am, brain the size of a planet and they ask me to take you down to the bridge

June 14, 2016 3:20 pm

These are not the planets you are looking for.

June 14, 2016 3:46 pm

Does anyone know what the orbit of this planet looks like? Does it orbit around the ecliptic of the two suns? or perhaps it has a “polar” orbit perpendicular to the orbit of the suns around their gravitational center?

george e. smith
Reply to  BobM
June 14, 2016 5:24 pm

The so-called ” three body problem ” has at least one known stable solution.
ANY three massive bodies ( of course isolated from any other massive bodies) can have a stable equilateral triangle configuration.
The “Trojan” asteroids in Jupiter’s orbit, are examples of a stable three body (sun, Jupiter, Trojan) system. They are grouped about 60 degrees ahead of, and behind Jupiter in its solar orbit.
So such a planet could orbit ANY binary star, that has a nearly constant orbital radius.
If I’m rong, somebody will correct me.

Owen in GA
Reply to  george e. smith
June 14, 2016 5:59 pm

Are you certain those are not in a Lagrangian point? There are places in any three body that are stable – one ahead in the orbit, one behind in the orbit, one inside the orbit, one outside the orbit, and one on the opposite side. The inside and outside are not as stable as the ahead and behind. but these are used by NASA for telescope placement and other purposes in the Earth-Moon system and the Earth-Sun system. (I just looked it up. They are indeed in the Lagrange points.)
That was one of the configurations I did not try in my simulation, because I could think of no evolution from dust clouds to put two stars and an Earth-like planet in that configuration.That would be a relatively trivial configuration to calculate, just make the distance of a leg:
and instantly the radiation number is correct and the orbits work.

Javert Chip
Reply to  george e. smith
June 14, 2016 7:52 pm

Well, you did spell “rong” wrong.

Smokey (Can't do a thing about wildfires)
Reply to  george e. smith
June 15, 2016 1:57 am

George e. smith, that is one potential solution, but it is not one that has yet been found in a stellar-planetary system to date.
Another potentially common (but not yet found) variety would involve a planet and a smaller star both orbiting the same central star. Our solar system is thought to have missed this by a few rungs, due to Jupiter not having enough mass to sustain stellar fusion (think “Odyssey: 2010”). This would result in our current planets having their orbits adjusted due to the obviously different effects of a 10x Jupiter-mass star tugging on the rest of the system, but the overall LOOK of our solar system might otherwise remain substantially unchanged.
The handful of so-called “Tatooine” worlds found in habitable zones to this point — implications to the contrary, this article simply describes the latest, largest such world to be confirmed — all orbit at some distance from a central co-orbiting binary. As long as these exoplanets don’t form &/or migrate too close to the central pair, an orbit about the pair’s barycenter is potentially quite stable, and can (for most purposes) be simplified to a two-body problem. It’s only when said exoplanet strays too close to the co-orbiting pair that the problem become complex to the point of ridiculosity.

george e. smith
Reply to  george e. smith
June 15, 2016 9:23 pm

Well Owen, I am certain that I did not say they were not at a Lagrangian point. I even believe that I said they were in jupiter’s orbit about the sun, either 60 degrees ahead or 60 degrees behind the planet. In fact the very first two Lagrangian points you mentioned.
Now to the extent that a planet like Jupiter, may NOT orbit the sun in a perfectly circular orbit, then those Lagrangian points would wander. And given enough planetary orbit eccentricity, they could ultimately get tossed out of such stable locations.
But any three bodies of any mass ratios can orbit stably in an equilateral triangle configuration. and if one of the masses is miniscule compared to the other two, then a fourth such body (second planet) could be added on the opposite side of the line joining the two suns., in another equilateral triangle.
And yes; why could there not be stable binary pairs with ALL of the Lagrangian points occupied by lesser bodies ??

Reply to  george e. smith
June 19, 2016 3:16 pm

george e. smith
You are correct, if a planet orbits two stars, there are several points of gravitational influence where a planet could orbit, theoretically a dense planet could even orbit outside two stars orbiting each other and have a stable orbit, the gravitational timing would have to be very slow. Each star would slightly change the planets orbit but as this happens slowly, the planetary orbit stabilizes with the barycenter of both stars.

June 14, 2016 8:00 pm

Interestingly, its orbit puts the planet within the so-called habitable zone.

Why do people think things have to be “Earth-like” to support life or be in the “so-called habitable” zone? Is this not a bias of our own making? How do we know how “life” might evolve elsewhere? Is it not rather strange thinking that “life” has to follow our definitions?

Smokey (Can't do a thing about wildfires)
Reply to  Wayne Delbeke
June 15, 2016 2:12 am

@Wayne Delbeke: The definition of “habitable zone” is rather broad, and consists mainly of determining whether — based on the exoplanet’s orbital distance and the stellar type of its host star — liquid water can possibly exist on the surface of that body at some point during its normal orbit.
Liquid water is used as the defining material simply because of its seemingly universal commonality with life, especially as we know it, and because of our own anthropogenic tendency to interpret words like “habitable” as meaning “habitable FOR US.” The inside edge of these zones are thus intended to indicate spots where water might be gaseous most of the time with some liquid water still present, while the outer edge shows where it might be frozen most of the time instead.
Only a modest allowance is made of atmospheric and other effects (solar flaring, etc.), and we already know this can be slightly misleading to the average person looking for “The Next Earth(tm).” To demonstrate, most diagrams of our own Solar system show Venus & Mars either within, or just barely without, the Sun’s habitable zone.
It is precisely the “vagueness” of this term which has most scientists, let alone the rest of us, using the term “so-called habitable zone” in the first place.

Smokey (Can't do a thing about wildfires)
Reply to  Smokey (Can't do a thing about wildfires)
June 15, 2016 8:40 am

Incidentally, Wayne (et al.), the real “STAR WARS” angle in this story is not so much that an exoplanet exists in a so-called “habitable” orbit around a double star (a la, Tatooine), but that we might someday see habitable, Earth-like moons orbiting this and other giant worlds that look similar to the one used in “A New Hope” for a Rebel base on Yavin’s 4th moon.
True, our experience w/Jupiter & Saturn tends to show that radiation is probably going to be a Jovian concern in such cases, but this may not be true with all gas giants, and the moons orbiting said giants might be far enough away from the parent body to avoid the bulk of the radiation pouring from it’s magnetic field in any case.

Smokey (Can't do a thing about wildfires)
Reply to  Smokey (Can't do a thing about wildfires)
June 15, 2016 8:46 am

All together now:
Oooooooh, It’s = contraction of “it is,” and
Its = possessive of “it,” as in “its arm,” “its orbit,” etc…

I swear I know the difference. I blame the arcane algorithms of Auto-Correct Ate…. 😉

Reply to  Smokey (Can't do a thing about wildfires)
June 15, 2016 7:20 pm

Thanks for the explanation. But call me skeptical. Radiation seems to be something that is said to be a barrier. Yet we have bacteria fouling screens in radioactive areas of nuclear reactors and growing on spent fuel rods.
I still wonder if we are not defining life in terms of our experience. Like when they used to say traveling too fast on a train would kill us [well, maybe from the smoke in an open car 😉 ].
Would we recognize a different life form if we saw it?
How solid is a wood table if a neutron can pass right though it like its a seive?
Who would believe you if you told an people that didn’t know about atomic particles?
But thanks for the explanation and the time to post it. Much appreciated.
I listen to science programs all the time. My recollection is that the building blocks of life as we know it are scattered throughout our galaxy/universe.
Does it have to evolve into a carbon based life form? Is water a necessary part? Archaea live at as much as 121C. Look at extremophiles. And that’s just on Earth.
Too many science fiction books in my youth perhaps.
Have a good day.
Jeez. News just said Frost Advisory for tonight. Love this country I live in.

Smokey (Can't do a thing about wildfires)
Reply to  Smokey (Can't do a thing about wildfires)
June 16, 2016 1:54 am

@Wayne: you’re definitely not wrong in pointing out that even on Earth there’s life that can survive & thrive in situations where you & I wouldn’t even leave behind a suspicious puddle of goo. =D
It might help to remember that the extremophiles we’ve found so far occur in places where liquid water is either naturally present (e.g. deep sea vents where the pressure prevents 300+C water from boiling away), or is created/maintained despite local conditions (e.g. Arctic/Antarctic bacteria which produce a biological “antifreeze” which melts surrounding ice at Mars-like temperatures and then keeps it that way, at least inside the organism). That water may be blindingly acidic, or caustically basic, but it’s still water, albeit w/stuff in.
The fact that liquid water seems to be the key to ALL of what we current recognize as life is why we continue to focus on the possibility of liquid water’s existence on a given world, and why that so-called “habitable zone” is usually drawn very, very broadly. (I once again point out that -40C Mars &/or +500Venus are usually drawn within the boundaries of Sol’s “habitable” zone.) There are those who say we should also calculate such zones around giant planets regardless of their distance from the host star, since the radiation fields and gravitation tidal flexing associated w/the orbits of any large moons could easily be imagined as sources of heat/food for life (e.g. the sub-surface oceans of the Jovian moons). The trouble is we have only broad understandings of those environments & systems (not to mention the critters living there, if any), and so unlike our star, we have no concrete way to drawn such a zone around, e.g. Jupiter.
I do tend to agree that the term “habitable zone” is not a scientific term, not really. By the same token, it does give us reasonable a “rule of thumb, for now” to determine whether a given world might potentially be habitable to humans & their attendant biospheres, so I don’t automatically twitch and start breathing hard when it shows up: it’s a term used for broad categorization, and for public outreach & consumption, nothing more; it should NOT be used for anything else at this point.
“Would we recognize a different life form if we saw it?”
That’s a big question, one that we can’t answer scientifically yet. Certainly some forms of life which are supremely alien to us are known to exist — e.g., your nuclear cooling water bacteria (again, in the liquid water environment!) — but they were somehow still recognizable to us scientifically as “life.” Such examples cannot logically be taken as proof of an unfailing human/instrumental ability to recognize ALL such life, and so we’re scientifically limited to focus on “the life as might know it/recognize it,” all the while keeping our big human brains open for any signs which might point us toward something beyond our current understanding.
In this type of hunt, pareidolia is often your friend. Put another way, just because the “Faces on Mars” usually go away after a second, closer look doesn’t mean that ALL of them have, or will in the future, or even that we won’t learn something interesting in the process anyway! In the meantime we’ll all continue to wait for a better definition of “ALL LIFE, EVERYWHERE” to come along so we can adjust our understanding, terminology and (most importantly) our search for such accordingly.
Sorry for the long reply. I work with space stuff for a living, and any discussion that talks about why/how we know the things we know, or that scientifically pushes the boundaries of what is or what might come to be… well, that’s just my kind of “mind expanding” addiction. ^_^

Smokey (Can't do a thing about wildfires)
Reply to  Smokey (Can't do a thing about wildfires)
June 16, 2016 2:03 am

ETA: temps for Mars & Venus are very gross averages/guesstimates, and vary considerably (hundreds of degrees) depending on where/when one measures.
Thank YOU, remote sensing, for allowing us to “see” the surface of a planet like Venus; I DO NOT WANT TO GO THERE, EVER, kthxbai!

June 14, 2016 11:58 pm


June 15, 2016 6:31 am

OK. What does the orbit of a Tatooine planet look like?

Smokey (Can't do a thing about wildfires)
June 15, 2016 7:02 am

@GP Hanner:
Go to the bottom image that’s still part of the article: That will show you the orbits of all previously confirmed “Tatooine” exoplanets on the same scale, just super-imposed on top of each other as though they were all in the same system (they aren’t). You can see the exoplanet in question is much further out from its hosts than any of the others confirmed to date.
Of note is that all of the host binaries are relatively close in size & distance to one another, which allows us to pretend all these exoplanets orbit the SAME pair. This makes it possible to show all such orbits on the same scale in the same diagram in the link above. Also, note that the orbits of the exoplanets are all fairly close to what we generally find in our own solar system — stable, near-circular ellipses — despite the binary hosts.

Owen in GA
Reply to  Smokey (Can't do a thing about wildfires)
June 15, 2016 10:03 am

Is this the image?
It is interesting but I don’t see the estimate of the habitable zone on there and that would be somewhat helpful. (yes I am terra-centric in my outlook.)

Smokey (Can't do a thing about wildfires)
Reply to  Owen in GA
June 16, 2016 12:40 am

Yes, Owen, and you’re right: while the diagram does show the inner boundary of stable elliptical orbits, it does NOT show the habitable zone(s). I believe the reason they don’t show the habitable zones on this diagram is because while the stars are all mostly similar in size/type, there are enough differences between them that when combined with the differences in planetary sizes, the result is differences in the habitable zones of each system which are significant enough to prevent overlaying them all with the same zone.
I’m unable to find an image of this particular exoplanetary system’s habitable zone quickly, at least one I can say for sure belongs to this particular exoplanet. My understanding is that this one’s “habitable” zone extends more in than out from this world’s orbit, but I still haven’t even had a chance to read the paper for detail yet, so I wouldn’t trust me on that just yet.

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