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NASA's Kepler Discovers Multiple Planets Orbiting a Pair of Stars

Unknown Lamer posted more than 2 years ago | from the next-week-aliens dept.

NASA 121

DevotedSkeptic writes "Kepler has continued its stellar (pun intended) discovery spree, this time locating multiple planets orbiting a binary star system. This is especially interesting because it proves that more than one planet can form under the stresses of a binary star system. The system is known as a circumbinary planetary system, a mechanism where a planet orbits two stars. Prior to this discovery, having multiple planets in a circumbinary system was unproven. Named Kepler-47, the system consists of a pair of orbiting stars that eclipse each other every 7.5 days. One star is similar in size to our Sol, however it only provides approximately 84% of Sol's light, the other is smaller, measuring one third of the size of Sol and emits less than 1% of Sol's light. Kepler-47b is the closer planet to its two suns, orbiting in 50 Earth days. Kepler-47c is further out and orbits every 303 days, within the Goldilocks zone. 'Unlike our sun, many stars are part of multiple-star systems where two or more stars orbit one another. The question always has been — do they have planets and planetary systems? This Kepler discovery proves that they do,' said William Borucki, Kepler mission principal investigator at NASA's Ames Research Center in Moffett Field, Calif. 'In our search for habitable planets, we have found more opportunities for life to exist.'"

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well ... (4, Funny)

therealkevinkretz (1585825) | more than 2 years ago | (#41167001)

I just wanted to have the first Tattoine reference

Re:well ... (1)

DiamondGeezer (872237) | more than 2 years ago | (#41167027)

You win for now...nerd

Re:well ... (5, Interesting)

mcgrew (92797) | more than 2 years ago | (#41167489)

You win for now...nerd

That's a compliment. Of course, even the mainstream news sites are saying this is "like Tatooine". Of course it isn't Tatooine itself, since Tatooine is long ago in a galaxy far, far away. This is in our own galaxy only 5000 light years away; the Mayans and Egyptians were still building pyramids when the light we're measuring left those stars.

What's exciting about this isn't that it's like Tatooine (or a lot of other science fiction star systems) but that it exists at all. It was formerly thought impossible for a binary star system to have planets. TFA I read earlier this morning said one of them was the size of Neptune and in the goldilocks zone, and wondered if the Neptune-sized planet had moons, and how strange it would be to be standing on one of those moons.

It seems likely that the outer, Neptune sized planet would have moons, since all the gas giants in our system do. Imagine, two suns, a HUGE GIANT moon (the planet) taking half the sky, and other moons visible as well.

Too bad it's impossible to get 5k light years away, I'd love to see the place.

Re:well ... (1)

interval1066 (668936) | more than 2 years ago | (#41167811)

Imagine, two suns, a HUGE GIANT moon (the planet) taking half the sky, and other moons visible as well.

Several classic fanatasy & sci-fi novel covers come to mind with your description.

Re:well ... (3, Funny)

Quiet_Desperation (858215) | more than 2 years ago | (#41168043)

Of course it isn't Tatooine itself

Yeah, we figured that bit out.

Re:well ... (2, Interesting)

wganz (113345) | more than 2 years ago | (#41169253)

You win for now...nerd

Too bad it's impossible to get 5k light years away, I'd love to see the place.

Always remember that The Royal Astronomical Society definitively proved that it was impossible for a passenger train to travel >= 32 mph lest all the oxygen would be sucked out of the rail car. It has to be true since it was proved with science!

Once the branch of mathematics is discovered that will solve such limits problems as division by zero and the speed of light; we could very well make that trip in a matter of minutes.

Yet another reason that we need to support pure basic fundamental research. (repetition was intentional)

Re:well ... (3, Interesting)

tnk1 (899206) | more than 2 years ago | (#41169869)

I know they said that the planets formed around the system, but I was wondering if they could also have been later captures of planets expelled from other systems by gravitational interaction. In other words, planets can certainly orbit multi-star systems, but they may still be unable to form under those conditions. My reading of the article doesn't seem to exclude that as a possibility although they appear to be very clear on the fact they think the planets were formed in that system.

Of course, you'd have to presume that it is possible for multiple objects to form in a system that is already multi-stellar, but the idea was never that they couldn't form, but that extreme gravitational conditions would eject extra matter as soon as the stellar objects formed, leaving only the most massive objects to be stable over long periods of time.

Re:well ... (1)

VIPERsssss (907375) | more than 2 years ago | (#41170859)

It was formerly thought impossible for a binary star system to have planets.

How is that much different than a system with a large gas giant?

Re:well ... (2, Interesting)

Anonymous Coward | more than 2 years ago | (#41171119)

It was formerly thought impossible for a binary star system to have planets.

It wasn't thought that to be impossible for binary systems to have planets, only thought that it is impossible for some situations. Orbits can quickly become unstable when you have a planet trying to navigate its way closely around two stars. However, orbits are just fine if the two stars are much closer together than the planet's orbit in which case the two stars almost act like a single central body (e.g. like this discovery), or if one of the stars is very far away, at which point the second start is like a distant gas giant or another planet around the system.

More recent work has asked questions of what binary systems due to a protoplanetary disk, and if it could prevent planet formation. Sometimes configurations do make planets much harder to form, but others were found to make it easier.

Re:well ... (0)

Anonymous Coward | more than 2 years ago | (#41167117)

In all your eagerness to win the unholy honor of spoiling the virginity of this fresh post, you've also successfully misspelled Tatooine.

The Force is pretty non-existent in this one.

Re:well ... (2)

Samantha Wright (1324923) | more than 2 years ago | (#41167343)

Fox News beat you to it— they titled this story "Alien planets found with twin suns like Luke Skywalker's homeworld [foxnews.com] ."

Re:well ... (0)

Anonymous Coward | more than 2 years ago | (#41167551)

I'm surprised fox didn't point out how tough it must be for god to have to make sure all those little light wobbles keep coming our way.

Re:well ... (1)

Samantha Wright (1324923) | more than 2 years ago | (#41167669)

I'd like think the fact that they had to dumb down "Tatooine" so hard that it takes up half of the headline speaks for itself.

Re:well ... (0)

Anonymous Coward | more than 2 years ago | (#41168027)

Yeah, because if you're not a Star Wars fan you must be some kind of moron.
 
Get over yourself and your culture. Plenty of people do just fine without sucking at the teat of George Lucas.

Re:well ... (2)

Gr8Apes (679165) | more than 2 years ago | (#41168079)

Get over yourself and go back to watching Snooki...

Re:well ... (0)

Anonymous Coward | more than 2 years ago | (#41168507)

Awwww. Did wittle fanboi get his wittle feewings hurt? Awww...

Re:well ... (1)

Gr8Apes (679165) | more than 2 years ago | (#41172193)

Nope - could care less about Star Wars. But apparently you know Snooki.

Re:well ... (2)

Samantha Wright (1324923) | more than 2 years ago | (#41170637)

Woah, woah, woah—I'm not a Star Wars person at all. And I doubt the BBC, who just said "Tatooine" in their headline, assumed everyone would be. It's a much more neutral statement about willingness to accept references one might not get. If you want to put it to fisticuffs, though, I personally think the reference should be left out entirely; 'binary star' or the even more basic 'twin star' would do the job just fine.

Re:well ... (0)

Anonymous Coward | more than 2 years ago | (#41170769)

Maybe if you said that they had to dumb down the term binary star to Star Wars reference that would have made more sense. Instead you made it seem that having to dumb down the Star Wars reference somehow "speaks for itself."

Re:well ... (1)

Quiet_Desperation (858215) | more than 2 years ago | (#41168107)

Speaks to the fact that not everyone is a Star Wars nerd? *shrug* That series lost real relevance and died long, long ago even before the prequels.

I just like the fact that everyone who said "Derp! Binaries can't have teh planetses!" over the years are all owned now. Science!

Re:well ... (1)

tnk1 (899206) | more than 2 years ago | (#41169971)

I don't think anyone stated that a binary system couldn't have planets, such as via a capture of a planet expelled from another system. The whole issue was with them forming in the system from the beginning and staying in the system. A gravitational system with more than one strong central point might well have certain characteristics that would tend to catapult matter out of it as the dynamics of the initial system evolved. In theory, there certainly could be a stable orbit around a binary system, but it might have been difficult to achieve that from an initial starting point in the protostellar disk as opposed to captures.

Re:well ... (1)

Quiet_Desperation (858215) | more than 2 years ago | (#41170633)

Well, yeah, that was the main two arguments back in the day. [1] They can't form in the first place or [2] if formed, they'd eventually be ejected. Don't recall anyone floating the capture after the fact theory. Not sure if rogue planets were considered a thing yet.

Re:well ... (1)

Anonymous Coward | more than 2 years ago | (#41171919)

Well, yeah, that was the main two arguments back in the day. [1] They can't form in the first place or [2] if formed, they'd eventually be ejected. Don't recall anyone floating the capture after the fact theory. Not sure if rogue planets were considered a thing yet.

If rouge planets hadn't been considered yet, what did they think happened to all the planets that go thrown out of binary systems in #2?

Re:well ... (1)

Culture20 (968837) | more than 2 years ago | (#41167595)

Yeah, well I have the first Twinsen reference.

Re:well ... (1)

mcspoo (933106) | more than 2 years ago | (#41167819)

No one has mentioned 2010 and Jupiter turning into a sun, so I'll throw that one out there too.

Never say (4, Insightful)

geekoid (135745) | more than 2 years ago | (#41167095)

"Pun Intended". Either people get it, or they don't. It's not clever if you have to point it out.

Re:Never say (2)

Trepidity (597) | more than 2 years ago | (#41167365)

Similarly, "no pun intended" has only quite limited uses, since by its nature it calls attention to the pun.

Re:Never say (1)

Anonymous Coward | more than 2 years ago | (#41168695)

Yet it can be entertaining to append "no pun intended" to something that does not contain anything that could be a pun. Some people will spend hours wondering where that pun is.

Re:Never say (0)

Anonymous Coward | more than 2 years ago | (#41168879)

Is "no pun intended" ever used in a non-sarcastic way?

Re:Never say (1)

chispito (1870390) | more than 2 years ago | (#41169267)

Similarly, "no pun intended" has only quite limited uses, since by its nature it calls attention to the pun.

Sometimes the most accurate way to describe something sounds like a joke. You're not saying it isn't funny, you're saying it's accurate.

Re:Never say (1)

Chris Burke (6130) | more than 2 years ago | (#41169397)

Yeah, I've always questioned that phrase, since while the pun might not have been intentional, your decision to call attention to it rather than changing your wording to avoid the pun certainly was.

Re:Never say (0)

Anonymous Coward | more than 2 years ago | (#41169585)

Sometimes you say something without time to analyze every interpretation of it, and only after you have spoken the phrase out loud do you realize that it could be misconstrued as a pun. Therefore, it is certainly appropriate to say "No pun intended" or something similar, especially when it changes the tone or meaning of the sentence.

Re:Never say (1)

Chris Burke (6130) | more than 2 years ago | (#41169777)

When speaking, of course, because you can't change your spoken words after saying them.

Writing "no pun intended" rather than going back and editing to remove the pun means that the pun's continued existence is in fact intentional.

Re:Never say (1)

HornWumpus (783565) | more than 2 years ago | (#41167609)

Never say puns, period. They aren't funny and neither are you. (not you geekoid, punsters)

Re:Never say (4, Funny)

Quiet_Desperation (858215) | more than 2 years ago | (#41168167)

Yeah, people who use them should be punished. Severely. I'm talking use a pun go to jail level of enforcement.

Re:Never say (1)

Patch86 (1465427) | more than 2 years ago | (#41168547)

Yeah, people who use them should be punished.

Intended?

Re:Never say (1)

Quiet_Desperation (858215) | more than 2 years ago | (#41168623)

Just engaging in some punditry.

Re:Never say (1)

HappyHead (11389) | more than 2 years ago | (#41168727)

You punk! When are you going to stop punching the language around?

Re:Never say (0)

Anonymous Coward | more than 2 years ago | (#41168843)

You punk! When are you going to stop punching the language around?

Get off your puny ass you dim witted pundit.

Re:Never say (0)

Anonymous Coward | more than 2 years ago | (#41168779)

Yeah, people who use them should be punished. Severely. I'm talking use a pun go to jail level of enforcement.

But what of the incorrigible punster? Are you suggesting we stop incorriging them?

Re:Never say (1)

Chris Burke (6130) | more than 2 years ago | (#41169429)

I'm talking use a pun go to jail level of enforcement.

Seems excessive. Surely punitive damages would be more appropriate.

Re:Never say (1)

Quiet_Desperation (858215) | more than 2 years ago | (#41170549)

Mother of God, what have I pun- er... done?

Re:Never say (2)

pclminion (145572) | more than 2 years ago | (#41171523)

I conducted a survey where I told ten different puns to a group of senior citizens. I wanted to see if any of the puns could make the people laugh. No pun in ten did.

Re:Never say (1)

Ransak (548582) | more than 2 years ago | (#41171541)

I'm talking use a pun go to jail level of enforcement.

That's awfully punitive.

Re:Never say (1)

Java Pimp (98454) | more than 2 years ago | (#41168463)

You forgot to include your "~" at the end of your comment.

Re:Never say (0)

Anonymous Coward | more than 2 years ago | (#41168937)

who the fuck cares what you think, glue sniffer.

Re:Never say (0)

Anonymous Coward | more than 2 years ago | (#41171147)

Puns are never clever anyways.

2nd grade editor? (0)

sanosuke001 (640243) | more than 2 years ago | (#41167179)

"this time locating a multiple planets orbiting a Binary Stars"

w.t.f.?

Science Turns Me On. (1)

Anonymous Coward | more than 2 years ago | (#41167181)

Finds like this and the expansion of human knowledge continues to amaze me. Every. Single. Time.

More funding for science!

Re:Science Turns Me On. (1)

GameboyRMH (1153867) | more than 2 years ago | (#41168993)

Are you a lady because I'm well-endowed with science :D

Liquid water? (1)

Lord Lemur (993283) | more than 2 years ago | (#41167187)

From TFA:
"The outer planet, Kepler-47c, orbits its host pair every 303 days, placing it in the so-called "habitable zone," the region in a planetary system where liquid water might exist on the surface of a planet. While not a world hospitable for life, Kepler-47c is thought to be a gaseous giant slightly larger than Neptune, where an atmosphere of thick bright water-vapor clouds might exist."

Wouldn't this cause some bizarre tidal forces too? IANAP, but seems that the relative masses of these bodies might lead to a excentric orbit that would push Kepler-47c into and out of the habitable zone.

Re:Liquid water? (5, Interesting)

dpilot (134227) | more than 2 years ago | (#41167567)

There are those who think that tidal forces are part of the reason complex and even intelligent life arose on Earth, and that without our highly-unlikely over-sized moon, we wouldn't be here to talk about it. We have temperature variations on the order of 20% (absolute) and call it "seasonal".

With that thought in mind, I've wondered if looking for a small rocky planet in the Goldilocks zone is the best way to look for life. I've wondered if a small rocky moon orbiting a gas giant might be a more likely place to find complex life. On the other hand it was disappointing to hear that there would never be colonies on Ganymede because of radiation near Jupiter, though I know nothing of the intensity, or whether a planetary magnetic field and atmosphere would shield it, etc.

Re:Liquid water? (1)

mr1911 (1942298) | more than 2 years ago | (#41167625)

IANAP, but seems that the relative masses of these bodies might lead to a excentric orbit that would push Kepler-47c into and out of the habitable zone.

Or you could RTFA. Actually you don't even have to RTFA since there is a graphic clearly showing one of the planets maintains an orbit well inside the habitable zone.

Re:Liquid water? (1)

Patch86 (1465427) | more than 2 years ago | (#41168635)

Unless I'm much mistaken, Earth's tides are mostly a result of the Earth-Moon gravitational interactions, not Earth-Sun. Obviously there will be some effects, but not major ones.

If there were liquid water on a moon orbiting a giant planet orbiting two stars (one of which is tiny), I'd assume the gravitational pull of the planet would more or less completely overwhelm the gravity from the two stars.

Re:Liquid water? (0)

Anonymous Coward | more than 2 years ago | (#41171237)

The tides from the sun are a little under 50% of the strength of the Moon's tide. In other words, out tides are about two parts lunar and one part solar. The combination is how we end up with spring and neap tides.

Re:Liquid water? (2)

Baloroth (2370816) | more than 2 years ago | (#41169385)

At those distances tides would be extremely minor. The Sun does have tidal effects on the Earth, but they are quite minor. The tidal effects of a binary star would be about the same (they would vary according to the orbit more than it does on Earth, but not enough to be an issue).

The much bigger problem would be the fact that the planet would vary in distance from a star according to it's orbit, much more so than the Earth does, even if the orbit isn't eccentric, simply because the suns are orbiting each other (probably fairly rapidly) and would therefore be closer and farther from the planet in turns. Depending on the separation, mass, and orbit of the stars, it is possible there isn't even a "goldilocks" zone, because the radiation in any orbit varies from high to low extremes too much as one star gets closer and farther. Most likely, though, one star is much smaller and will have little effect, or the radiation won't vary so much from the average that it will make a difference. It's hard to say because any such arrangement is a three-body gravity problem, so the solution is very complex (although you could model it as a 2 body assuming the planet is a point-mass to calculate the stars orbits, and the stars are a single body to calculate the planet's orbit, which is in most cases quite accurate).

Situations vacant: Slashdot editor (1)

wonkey_monkey (2592601) | more than 2 years ago | (#41167229)

a [sic] multiple planets orbiting a [sic] B[sic]inary S[sic]tars.

Really? I'll give the submitter the benefit of the doubt because English may not be their first language, but isn't this what we have editors for?

Kepler-47b is closer to its two suns orbiting in 50 Earth days.

Err, closer than what? Kepler-47a, I'm going to assume. No, I'm not going to RTFA. We are Slashdotters!

Re:Situations vacant: Slashdot editor (0)

Anonymous Coward | more than 2 years ago | (#41167545)

Fine...someone will have to explain it to you.

If you followed anything about exoplanet discovery, you would know the naming convension for planets. The first planet discovered is classified as '-b'. The next planet '-c' and so forth. The naming convension is based on when the planets are discovered, not how close to the star they orbit. The star (or stars) are named '-a'.

The more you know. [wikipedia.org]

Re:Situations vacant: Slashdot editor (1)

DevotedSkeptic (2715017) | more than 2 years ago | (#41167739)

Yes that was very poor proofreading on my part, and the editor missed it as well. Things happen we all make mistakes however I was not mistaken on the identity of the the two planets Kepler-47a and Kepler-47b. http://www.nasa.gov/mission_pages/kepler/news/kepler-47.html [nasa.gov]

Re:Situations vacant: Slashdot editor (1)

wonkey_monkey (2592601) | more than 2 years ago | (#41167887)

Erm, b and c - not sure why there isn't an a. And I see it now - when I read

Kepler-47b is closer to its two suns

It wasn't immediately clear that it simply meant "closer of the two planets" - I thought some other piece of text, perhaps referring to 47a, had been cut out.

Bad science article, sorry. (0, Troll)

Anonymous Coward | more than 2 years ago | (#41167437)

If you read this headline, the brighter star contributes 84% of the light, the dimmer star 1%. 84 + 1 = 85%, not the total 100.

If you read the linked through article, it says the brighter star is 84% as bright AS our Sun, and the dimmer star 1% as bright As our Sun.

Sigh

Do they have a figure 8 orbit? (0)

Anonymous Coward | more than 2 years ago | (#41167493)

That would make for some interesting tides and seasons.

Re:Do they have a figure 8 orbit? (2, Informative)

sgunhouse (1050564) | more than 2 years ago | (#41168173)

Not possible given the orbital periods. Both planets orbit outside the orbits of the twin stars. (That's the definition of circumbinary, also.)

Re:Do they have a figure 8 orbit? (1)

mister_playboy (1474163) | more than 2 years ago | (#41170819)

A "figure 8" orbit would also probably require stars of very similar mass for it to be stable over astronomical timescales.

These stars are too different in mass for that, IMO.

khatulistiwa.ihza@gmail.com (-1)

Anonymous Coward | more than 2 years ago | (#41167511)

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http://weddingorganizeryogyakarta.blogspot.com/ (-1)

Anonymous Coward | more than 2 years ago | (#41167537)

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informAtive 7rollkoretrollkore (-1)

Anonymous Coward | more than 2 years ago | (#41167655)

between eAch BSD

More editing needed (1)

creelbm (2718189) | more than 2 years ago | (#41167703)

Ok, this writer clearly isn't a scientist. They say that 84% of the light of the system comes from the brighter star, and 1% from the dimmer. That's all the light, right?...84 + 1 != 100 If you read the original NASA article, they said the brighter star is 84% as bright as our Sun and the dimmer one 1% as bright as our Sun. *sigh*

Re:More editing needed (1)

Urza9814 (883915) | more than 2 years ago | (#41168157)

It could have been phrased better, I admit, but the way it's phrased is pretty common. I also don't see how you possibly got '84% of the system's light output' in a section where they were clearly comparing it to our Sun. The use of the word 'however' is a pretty clear indicator that they're continuing the current comparison, not jumping off to something completely different.

If I said to you 'my car is just as big as John's but only needs half the gas' would you think I mean half of the entire world's supply of gasoline, or that my car has twice the fuel efficiency of John's?

Re:More editing needed (1)

sgunhouse (1050564) | more than 2 years ago | (#41168209)

84% of Sol's light, and likewise 1%. Combined, they still have 15% less light than Sol at the same distance.

Re:More editing needed (1)

mark-t (151149) | more than 2 years ago | (#41168277)

You've misread it. Permit me to quote...

One star is similar in size to our Sol however it only provides approximately 84% of the light, the other is smaller measuring one third of the size of our Sol and emits less than 1% the light.

This isn't saying that one star provides 84% of the light in the system, it's saying that one star provides 84% of the light as our own sun. The other 1%. Obviously, the total amount of light is only 85% of our own sun.

Nowhere do the percentages read as being relative to the total light in that system, but only relative to our own. The percentages don't have to add up to a hundred in that case... they can add up to less, or more, because they are being compared to something else, not to their own net total.

7.5 days? (2)

Rich0 (548339) | more than 2 years ago | (#41167751)

Seems like a bit of a degenerate case to me. The two stars orbit each other each 7.5 days. I wouldn't be surprised if their atmospheres practically overlapped with that kind of distance. The planets essentially would be orbiting the center of mass of the two stars as a result. I wonder if they'd eventually merge, and what would happen then.

I think that this situation is likely to be a lot more stable than having another star orbiting further out than the planets.

Re:7.5 days? (5, Informative)

creelbm (2718189) | more than 2 years ago | (#41167939)

Using Kepler's 3rd Law, a^3 = p^2, with a = average orbital separation in AU (Earth to Sun distance), and p the orbital period in years: a = (7/365)^(2/3) = 0.07 AU. 1 solar radius is about 0.0046 AU. Go to the original paper here: http://www.sciencemag.org/content/early/2012/08/27/science.1228380.abstract [sciencemag.org] and you see the larger star is about the size of our Sun, the smaller star 1/3 the size. 0.07 AU/0.0046(AU per radius) = 15.2 Solar radius separation between the stars. So, close but not close to overlapping.

Re:7.5 days? (0)

Anonymous Coward | more than 2 years ago | (#41168257)

For perspective, that ratio is very similar to the Pluto/Charon system, just obviously on a much smaller scale.

Hierarchical Star Systems (1)

Araes (1177047) | more than 2 years ago | (#41169679)

This is the simplest case, but its conceivable to have stability with a star orbiting farther out as well. In the case like this one, you could maintain accretion disk formation with much larger star separations as long as the separations weren't so large that they cleared all the material, or introduced significant eddies / disturbances in the disk. To a point, simulations have actually shown that a little bit of this stirring helps. Solar orbit distances are also often vast compared to planetary orbit distances, so the other extreme can occur, where there can be an extensive internal band of stability between two distant companions; thereby allowing inner planets to form around each star. Hierarchical star systems of 3, 4, 5, ect.. stars would also potentially produce stable planets as long as they had large gaps between the centers of mass and outer orbit paths of each sub-system. http://en.wikipedia.org/wiki/Multiple_star#Hierarchical_systems [wikipedia.org] for visualization of the hierarchical relationships.

Re:7.5 days? (1)

Hentes (2461350) | more than 2 years ago | (#41169987)

Not really, planets [wikipedia.org] orbiting one member [wikipedia.org] of a multiple-star system are fairly common.

Velocity? (1)

taiwanjohn (103839) | more than 2 years ago | (#41167903)

With a period of just 7 days, you have to wonder how fast the little bugger is moving. Could be a significant fraction of C...?

Re:Velocity? (5, Informative)

creelbm (2718189) | more than 2 years ago | (#41168037)

Looks like I'm fielding the astronomy numbers today. Ok, look at my response to the 7.5 days question. The stars are separated by 0.07 AU (distance Earth to Sun in our system). The center of gravity's closer to the more massive star, so let's say the center of mass is 1/4(0.07 AU) from the larger star. Assume a circular orbit (not a bad assumption). Then, v = 1/4*2PiR/(t) = 2*Pi*(1/4*0.07AU*1.15x10^11 m/AU)/4*(7 days*24*60*60) = 390,000 m/s = 3.9*10^5 m/s, a tiny fraction of c, which is 3*10^8 m/s. Fast, not that fast. 0.001 c

Re:Velocity? (1)

chichilalescu (1647065) | more than 2 years ago | (#41168769)

true, not a significant fraction of c.
but take into account that relativistic effects are noticeable (on the scale of 100 years) for Mercury, which orbits between 0.3 and 0.4 AU from the Sun. also take into account that these are heavy objects, and we might find that a satellite moving between these two stars could be used to study relativistic effects. I'm not gonna try to compute anything, but relativistic effects are noticeable for GPS satellites, so what I said must make sense.

obviously, the interesting results would be found if the poor thing didn't burn first...

Binary Star or binary star? (1)

Eponymous Hero (2090636) | more than 2 years ago | (#41168013)

binary star is not a proper noun unless you're talking about the old school hip hop group http://www.youtube.com/watch?v=okcRjRwFVLU [youtube.com]

Re:Binary Star or binary star? (1)

GodfatherofSoul (174979) | more than 2 years ago | (#41171539)

"old school" huh? You 7-digit posters...

Love the group btw

Re:Binary Star or binary star? (1)

Eponymous Hero (2090636) | more than 2 years ago | (#41172189)

=) i say old school cuz they came out in something like '97 or '98 and it's already almost '13. but you're right, old school is more like '91 and before. organized konfusion sounds a lot like binary star too, they're awesome.

Pandora-like moon... (1)

TheDarkMaster (1292526) | more than 2 years ago | (#41168081)

... on Kleper-47c? 47c maybe is a gas giant, but may have many rocky or ocean moons.

Point of order on Habitable Zone (2)

zerosomething (1353609) | more than 2 years ago | (#41168323)

We only have one known planet where life has occurred and is sustained. There is no prof, yet, that life ever occurred on Mars or any other planet in our system. At this point with what we actually know about life I think the "habitable zone" graphics on some of these press releases are overly optimistic. I hope we can find evidence of life on Mars so we can actually expand our "known" habitable zone.

Re:Point of order on Habitable Zone (0)

Anonymous Coward | more than 2 years ago | (#41168495)

Mars would generally be considered "within the habitable zone" by most standards.

The fact that it could maintain liquid water if it had a sufficient atmosphere to trap heat makes this so. It has nothing to do with having life on it.

Re:Point of order on Habitable Zone (2)

Hentes (2461350) | more than 2 years ago | (#41170069)

The point of the habitable zone is not that it proves that life exists on the planetas (Mars and Venus are also in the zone). It's quite the opposite, if a planet isn't within the zone we can exclude the possibility of life. Still, it's pointless to check for that when we are talking about a gas giant.

Re:Point of order on Habitable Zone (1)

tnk1 (899206) | more than 2 years ago | (#41170103)

I don't think the habitable zone requires Mars to have had life, although that would certainly confirm it.

A lot of the reason that Mars (or Venus for that matter) does not currently harbor life appears to be due to things like atmospheric volume, as well as the ability of the planet to undergo plate tectonics as opposed to complete crustal inversion to release core heat. That and core/mantle makeup which determines if there is a magnetic dynamo which can create a magnetic field.

You could have an otherwise perfect Earth-like planet in our same orbit, but if something happened like an insufficient quantity of water, an axial tilt that was not sufficient, or perhaps a planetary makeup without a sufficient ratio of radioactive elements, you might well be staring at a barren rock that never supported life.

Conversely, you could have a planet out by Mars which had a different, perhaps denser makeup, and you might well have a smaller, but completely viable terrestrial planet.

most, not many (2)

catmistake (814204) | more than 2 years ago | (#41168637)

Unlike our sun, many stars are part of multiple-star systems

IIRC from my star fighter days, most stars, the vast majority of them, are part of multiple-star systems. Sol is very weird and a rare counter-example in that regard.

Re:most, not many (0)

Anonymous Coward | more than 2 years ago | (#41169451)

IIRC from my star fighter days, most stars, the vast majority of them, are part of multiple-star systems. Sol is very weird and a rare counter-example in that regard.

Was this comment transported here from slashdot 2050 or have we already developed "star fighters"?

Re:most, not many (1)

JazzLad (935151) | more than 2 years ago | (#41169847)

He's posting from Kepler

Re:most, not many (1)

Baloroth (2370816) | more than 2 years ago | (#41169477)

According to this [harvard.edu] , most stars (2/3rds in the Milky Way) are actually single. Assuming other galaxies are similar in that respect to ours (which is safe, logical, and pretty much required given the difficulty involved in observing stars in other galaxies), most are probably single everywhere.

Re:most, not many (1)

Anonymous Coward | more than 2 years ago | (#41170015)

New science... it's not most stars, just that most bright stars that have stellar companions. Most dim stars are solo. Sol is still an odd one... a bright solo star.

Ya know.... (1)

hesaigo999ca (786966) | more than 2 years ago | (#41169265)

>Prior to this discovery, having multiple planets in a circumbinary system was unproven
Ok when movies like Star Wars come out with visible advanced knowledge that such things do exist, either it leads me to believe that many humans on this earth are really aliens mascarading as us and enjoying lives of financial freedom due to the use of knowledge that no one else would know... George....I know u r really an alien and actually just brought your story from another galaxy where you came from as a regular story of what your life was like back there...

OR

That the probability that all things no matter how far fetched do exist, and at some point we might be run over by an army of goblins and ogres like in Lord of the rings...Gandalf might need to be brought out of his deep cryogenic freeze once again.... or wait was that Demolition Man...?

I always get them mixed up.... :(

Re:Ya know.... (1)

tnk1 (899206) | more than 2 years ago | (#41170383)

It was never far-fetched or advanced to accept planets around a multiple star system. You could look at multi-moon systems around planets and just assume you could do that with stars too. It was merely a case in which the director's ignorance of current scientific thought was an advantage when the status quo was overturned.

It's just like those people who believe that it is only "a matter of time" before we break the speed of light. Currently, there's no way to even approach light speed in a spacecraft made up of any mass in existence. Relativity indicates that the energy requirement would become infinite no matter what the mass is as you approach c.

There may be ways to "cheat" (like wormholes) or perhaps some small, but extremely important bit of the puzzle we are missing that would allow us to make an exception under certain circumstances, but it is currently considered impossible to simply create an engine that will simply add more and more energy until we break the light speed barrier like we did the sound barrier.

However, if that unlikely event does somehow come to pass, it doesn't mean that all of the directors and sci-fi writers were inspired by aliens, they just happen to be extrapolating current progress into the future, and more often, making stuff up so that their chosen universe aligns with common expectations of what the "future" is going to be like. Some extrapolations or convenient fictions just tend to be more reasonable than others, but most tend to be almost hilariously incorrect. Just take a look at all the books and movies that used the assumption that Mars and Venus would definitely harbor life, even intelligent life, and then take a look at the reality we have discovered.

Am I the only one who read that as (0)

Anonymous Coward | more than 2 years ago | (#41169331)

NASA's Kepler Discovers Multiple Patents Orbiting a Pair of Stars?

ironic captcha: projects

What I would like to see (1)

Hentes (2461350) | more than 2 years ago | (#41170201)

A sparse multiple system with planets orbiting at least two of the stars. That would make for some good scifi for it would allow practical interstellar travel between the planets.

I once knew this Jewish guy named Sol. (0)

Anonymous Coward | more than 2 years ago | (#41170855)

Just sayin'

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