Exoplanet news Part 4: More wretched hives of scum and villany

By Phil Plait | January 13, 2012 11:29 am

[I'm trying to catch up with all the news that's been released this week while I was off lecturing in Texas. This is Part 2 of a few articles just about exoplanets. Here's Part 1, Part 2, and Part 3.]

Astronomers have found more Tatooines! Cool.

In September, astronomers announced the discovery of a planet (Kepler-16b) that orbited not one but two stars. The stars orbit each other (in what’s called a binary system) and the planet circles both. This was the first such planet found doing this (out of hundreds of planets orbiting single stars discovered), which opened up the question: how rare is this kind of system? Is Kepler-16b one of a kind?

The answer appears to be no: two more such systems have just been announced! Dubbed Kepler-34b and Kepler-35b, both are gas giants, similar in size to Saturn.

The planet Kepler-34b orbits two Sun-like stars once every 289 days. The two stars (Kepler-34A and Kepler-34B; note the capital letter denoting a star versus the lower case letter denoting a planet — which technically should be called Kepler-34(AB)b, but at some point I have to draw the line and simplify) orbit each other every 28 days. The planet Kepler35-b orbits a pair of somewhat lower-mass stars every 131 days (the stars orbit each other every 21 days).

Note that in both cases, the planets orbit their stars at distances much larger than the distances between the two stars themselves. That’s not surprising to me. From far away, a circumbinary planet (literally, "around two stars") feels the combined gravity of the two stars more than either individual star, much like distant headlights on the highway look like a single light. When you’re close, the two lights resolve themselves. Same thing with a planet; if it orbits much closer in the gravity field is a bit more distorted by the individual stars. Too close, and the orbit becomes unstable and the planet can be ejected from the system entirely! But it looks like both Kepler-34b and 35b have nice, stable orbits.

Binary stars are very common in the Milky Way: roughly half of all stars are binary, and now we know that at least three such systems have circumbinary planets. And we’ve only just started looking! Mind you, these planets were found using the transit method, so the orbits have to align just right from our viewpoint or else we don’t see them transit. For every one transiting system we find there are many more that exist but don’t transit, so we don’t see them. But they’re out there.

I suspect that the fraction of binary stars with planets is probably lower than for single stars, since planets forming (or moving) closer in to the binary center will get ejected. But still, even with a lower fraction we’re still talking about a pool of hundreds of billions of stars, so it’s likely that there are millions of circumbinary planets out there: millions of Tatooines!

And hmmmm. Kepler 34 and 35 are 4900 and 5400 light years away, respectively, making them among the more far-flung planetary systems seen. You might say that if there’s a bright center to the Universe, they’re the planets that it’s farthest from.

I’ve always dreamed of standing on a hill and watching twin suns set in the west. Sadly, the wind won’t blow through my hair like it did Luke Skywalker’s, but that would be a small price to pay. What a view that would be!

http://www.youtube.com/watch?v=305xoy0hKHw

[UPDATE: Wait a sec! Right after posting, I realized: the two planets are both gas giants, but far enough from their stars that big, terrestrial moons might be possible. So imagine that: a binary sunset with a gigantic planet looming in the sky as well! That would be incredible.]

Image credit: Lynette Cook and SDSU

CATEGORIZED UNDER: Astronomy, Cool stuff

Comments (59)

  1. Ok, someone with artistic skills *HAS* to render this image. An Earth-like world (yet very alien) with two setting suns and a rising planet. Or would such a world be tidally locked and (on one hemisphere at least), always have the planet in the sky?

  2. Your update caught my first thought too! I am starting to feel like our solar system got gypped and is just too boring.

    Another argument as to why no actual alien space ships really come here I would suppose? :D

  3. dcsohl

    Hmmm, both parts 3 and 4 of this series have announced that they are Part 2 in the first paragraph… Is it Groundhog Day?

  4. Beave

    Phil – remarking on your update: I can only imagine the terror of the tides on such an exomoon; giant planets do not a beachfront paradise or mountain retreat make, but rather hellish nightmares all around.

  5. Wzrd1

    Two thoughts arrived at once, when I read the article.
    1: Perturbations caused by the stars orbiting each other would probably generate eddies in the planetary cloud, thereby assisting in planetary development far faster than in our simpler system.
    2: Things in those close orbiting binary systems will most certainly get interesting when one star goes red giant! At an orbital period of 21 days, the non-giant will be inside of the outer layers of the red giant.
    Hmmmm, have any models been run where a main sequence star is inside of a companion red giant envelope?

  6. Assuming the two suns in Star Wars are the same size as our Sun, would a planet at Earth’s orbital distance be in a stable orbit, or would it have to be much farther away from the binary?

  7. Tim

    So, why do the planets’ letter designations start from ‘b’? I’d always assumed that the star itself was implied to be the system’s ‘a’ component, but, if stars and planets get the same letters, just differentiated by upper- and lowercase, why isn’t the first planet in a system called ‘a’?

  8. Jess Tauber

    On the optimistic side, assuming you live that long, by the time you can stand on a planet and watch a binary sunset I’m sure biologists will have long known how to let you enjoy the wind blowing through your Fabio-like tresses, and give you a body to suit (or any other for that matter, or antimatter as the case may be…), in both senses of the latter. :-)

  9. Daniel J. Andrews

    Larian has hit upon the answer as to why no aliens have visited. It is like a person who lives in some gorgeous mountain, ocean, tropical paradise with a riot of colours and then deciding if to come visit Iowa (or Saskatchewan), in February, alone, in the dark, surrounded by people slightly unhinged by mid-winter madness who want to vicariously live in the paradise by touching the paradise-stranger’s clothing and face, “Pretties I wants to touch the pretties, I musts touch the pretties,….”. (except in the alien case, we’d be throw in the word “dissection” at some point).

  10. amphiox

    A 289 day orbit is tantalizingly close to Earth’s 365 day year…. Where is the outer planet in relation to the binary pair’s habitable zone? (Assuming binary stars would have a habitable zone, though I can’t think of any reason why not.)

    Kepler 34 and 35 are 4900 and 5400 light years away, respectively, making them among the more far-flung planetary systems seen. You might say that if there’s a bright center to the Universe, they’re the planets that it’s farthest from.

    That’s only if you can consider Earth to be the bright center to the Universe!

    (Well, in a way, it is the bright center of our universe….)

  11. Pablo

    Interesting.

    “…since planets forming (or moving) closer in to the binary center will get ejected.”

    I wonder what the population of ejected planets might be. It would be fascinating to speculate on a civilization evolving on a planet that later got ejected from its home system. A planetary space ship. Gotta be a novel in there somewhere.

  12. Ken

    @LarianLeQuella: I recall a short story about alien tourists coming to see our solar eclipses, the match between size of moon and sun being incredibly rare. I think Asimov did a science column where he ran through the (then-known) moons and found no other close matches.

  13. kevbo

    Now do the theme to the “People’s Court”!

  14. Ken

    which technically should be called Kepler-34(AB)b

    So who has the naming rights to all these new planets? For that matter it sounds like most of the stars involved also need names…

  15. CR

    Regarding names of planets & stars…
    Does anybody remember the old sci-fi spoof “Dark Star”? It’s been a couple decades since I’ve seen it, but I recall that it had an opening sequence that featured a radio station (or the futuristic equivalent) broadcasting a song with a very clunky name, something along the lines of “Moonlight over XB-37219.” I thought it was funny then, but each time Phil makes one of these planetary announcements, I am reminded of that scene and it becomes all the more funny. (I’ll have to try to find a copy so that I can get the actual name correct.)
    UPDATE: Of course, the theme to the movie was “Benson, Arizona,” but I swear there was an announcement after that with the other (fictitious) title. I’m off to search for a clip…

  16. Wzrd1

    @CR, wow, couldn’t remember the name of that movie. I was dying with laughter over the argument with the smart bomb…
    IMDB has the basic info.
    Also, Wikipedia has a good article on it and it’s still available from Amazon.

  17. Bobby LaVesh

    So, could a planet orbiting a binary star exist in a “goldilocks” zone? Would the planet have to be too far out away from the stars to avoid gravitational disruption that it would be too cold for “earth-like” life?

    Could one suppose with enough geological activity or a really thick atmosphere that it would be warm enough for earth-like life to exist on a moon of one of those binary star planets?

  18. Bobby LaVesh

    ” It would be fascinating to speculate on a civilization evolving on a planet that later got ejected from its home system. A planetary space ship. Gotta be a novel in there somewhere.”

    There are lots of novels based on generation ships- I’d be surprised if at least one novel where a planet WAS the generation ship doesn’t exist. I think the novel EON was based on an asteroid as a generation ship.

    Also, your plot sounds fairly similar to that of “Space 1999″ the *ahem* fantastic sci-fi show where the moon is accidentally blasted out of earth’s orbit and the inhabitants of the futuristic space base (Moon Base Alpha if I recall correctly) were sent on a galactic voyage aboard the moon.

  19. CR

    OK, I found the title of the Dark Star tune… the ship’s computer lists it as the “perrenial favourite” ‘Twilight Falls on NGC-891.’ (Yes, that was going to bug me all day if I didn’t find out what it was!)

    @17: Space: 1999 is brought up more than occasionally here, Bobby. And yes, Moonbase Alpha was the main setting.

  20. Our solar system may be one up on Kepler-34, since we may have formed with a hierarchical triple star composed of a close binary pair orbited by a smaller tertiary stellar component (TSC) inside the orbit of Mercury.

    The TSC was resonance locked to the planets, causing the binary pair to decay and pushing itself and the planets outward in a event we’ll call ‘planet inflation’. Originally, Venus and Uranus may have formed between Earth and Jupiter, but as the orbits inflated, first one then the other moved into the 2:1 (Kirkwood Gap) resonance with Jupiter and were tossed into their current relative orbits, accounting for their highly inclined axial tilts. Mars and 4 Vesta are small because they formed late in the orbits vacated by Venus and Uranus.

    The binary pair merged in the primary luminous red nova (LRN) at about 4.5682 Ga, rolling the planetary accretion disk dust and gas out to the inner Oort cloud (IOC) which formed the IOC comet clusters and differentiated to form gneiss-schist-dolomite rocky cores (mantled gneiss domes).

    The TSC orbit became eccentric in the primary LRN, forming a contact binary with the sun at aphelion, streaming plasma from the sun which volatile depleted the terrestrial planets, causing the ‘planetary volatility trend’. Before volatile depletion, Venus and Earth may have been ice giants the size of Uranus and Neptune.

    The TSC merged with the sun in a secondary LRN, blasting the volatile-enriched solar envelope out to the outer Oort cloud (OOC) which formed the OOC comet clusters which differentiated to form volatile-enriched granite-greenstone rocky cores. The LRNe also formed the short-lived-radionuclides of the early solar system which caused the granite-greenstone comet cores to melt, forming massive plutonic granite.

    Schist-dolomite and greenstone are hydrothermal rock formed from diagenesis and lithification of the underlying gneiss and granite respectively.

    Comet clusters underwent core collapse (similar to stellar globular clusters) by evaporating off the smaller comets, causing the larger comets to settle into the collapsed core and merge to form far-larger compound comets, such as the Sierra-Nevada (OOC) compound-comet core and the Appalachian-Basin-Province (IOC) compound-comet core.

  21. Chris A.

    @Mike Sperry (#6):
    “Assuming the two suns in Star Wars are the same size as our Sun, would a planet at Earth’s orbital distance be in a stable orbit, or would it have to be much farther away from the binary?”

    The short answer is that it depends partly on how far apart the twin suns are from each other (the closer together they are, the more stable the planet’s orbit will be).

    But ultimately the question boils down to: Stable for how long? Earth is currently in a multi-body system (Jupiter, etc.), so its orbit is being constantly perturbed, and given enough time, would change into a less pleasant orbit. Luckily, that time span is at least as long as the sun’s remaining life span, and thus isn’t something our distant descendants will have to worry about.

    Determining the stability of an orbit in an n-body system requires doing massive number crunching–there’s no closed formula. However: With twice as much stellar mass to orbit, at 1 AU the hypothetical planet’s year would be about 258 days long (365 days divided by the square root of 2).

  22. dave chamberlin

    For a nice stable planet temperature wise and free of pesty asteriods one sun good, two suns bad.

  23. dcortesi

    I am boggled by the data extraction skills of the Kepler people! You can see (and help analyze) Kepler light curves at http://www.planethunters.org/, which I’ve done, and they are messy for single-star systems. But the light curve for a binary, with big hairy dips as the stars eclipse each other every 21 days, with one little pip every 289 days? Mmmph!

    (I’m assuming that if the planet’s orbital plane is edge-on to us (else Kepler couldn’t see it), then so also is the two stars’ mutual orbit. You wouldn’t get a planetary disc that isn’t the same as the parent stars’ orbital plane — would you?)

  24. Margrit McIntosh

    When someone asked George Lucas which was his favorite bit from Star Wars, he said it was the binary sunset scene. (And of course when I read that I went “ME TOO!! OH GOD ME TOO GEORGE YOU ARE MY SOUL MATE!!!)

  25. Ian Perera

    LarianLeQuella: You should be thankful that we have an entire solar system’s diversity combined in one planet.

  26. andy

    Kepler-16 (AB) b the first circumbinary planet? I’d have to dispute that.

    Actually the first planet discovered in a circumbinary orbit was discovered in 1993, way before Kepler was launched. Located in the globular cluster Messier 4, the PSR B1620-26 system consists of a millisecond pulsar+white dwarf binary with an orbiting planet. I guess pulsar planets just get routinely ignored: the number of claims of “smallest known exoplanet” which ignore the other known pulsar planet system PSR B1257+12* is quite embarrassing really.

    There are also some other circumbinary planets detected in post-common-envelope binaries via the timing method that were also announced before Kepler-16 (AB) b showed up, e.g. the HW Virginis and DP Leonis systems. Some doubts have been raised about some of these latter systems, but the case for a planet at PSR B1620-26 is quite robust.

    * The companion of PSR J1719-1438 has also been described as a “diamond planet” but really it is just an extremely low mass white dwarf star.

  27. Chris

    So if we found a moon would it be called Kepler-34((AB)b)b? The image you are thinking of is of Pandora in Avatar. It takes place around the moon of a gas giant in the Alpha Centauri system. Too bad they never had the setting binary suns.

    But wouldn’t the terresterial moons be way too hot? You have 2 sun-like stars heating you up so your orbit would probably have to be about 1.4 times the earths. Wonder if the planet would have cold spells as the one sun eclipsed the other. Also interesting how a society would develop their belief system.

  28. Steve D

    If any of these gas giants have moons, they’d almost certainly be tidally locked to their planet. A day on such a moon would be a month – one orbit around the planet. Something like Io, with a period around 42 hours, would possibly be livable, but something like Callisto, with a period of nearly 17 days, might be a bit more challenging.

  29. Terrestrial moons orbiting a gas giant in a binary star-system? That’s not Tatooine, that’s ENDOR!

    Any fellow lifeless geeks curious about the feasibility of Star Wars planets, click my name for a rough study by Dr Curtis Saxton, who was also involved in writing of a number of Star Wars reference books by DK.

  30. amphiox

    Your update caught my first thought too! I am starting to feel like our solar system got gypped and is just too boring.

    A hypothetical alien civ on such a binary star gas giant moon world might have a different perspective on “boring”.

    “Only one star??? A naked world, with no giant companion, in the habitable zone?! Eight (nine) planets??!! TWO distinct debris belts around the star??? How cool is that!!!!”

  31. I used to wonder how a system like that would work – would the planet be in between the stars, orbiting one and then the other? But now I think that if your primary star has a companion, your planet could be orbiting outside the orbit of the companion – apparently the Tatooine case – so that you see two suns all the time. Or your planet could be inside the companion’s orbit. Depending on how far out the companion is, it could light up the sky at night rather like our moon does, but at certain times of the year rather than the month. Or perhaps the companion has a wide orbit, and only looks like a bright star at night.

    Of course, the real focus of your planet’s orbit, and the center of the system’s gravity, would depend on the masses of the stars and how close they are to each other. Certainly planets could get tossed out in such a situation, but there would be no reason to assume that all of them would, would there?

    And Dave, I love your theory of the sun as originally a triple star. Is that written up anywhere? Or are you pulling our legs?

  32. Messier Tidy Upper

    @ ^ Jen Deland : I’m not sure about the triple star theory – that’s a new one to me – but I’ve certainly read one theory about our Sun once being a close binary that became a contact binary (or W Ursae Majoris variable) then merged together into our Sun as we know it today :

    “It sounds like science fiction,” says Bradstreet [Dave Bradstreet eastern College Pennsylvania - ed.] but our Sun could’ve been a contact binary four or five billion years ago and we might never know it.” The only witnesses to the event would have been astronomers who lived long ago elsewhere in the Galaxy, who puzzled over the behaviour of the peculiar binary star that wa sto become our Sun – just as we now puzzle over ER Vulpeculae.”

    Source : Page 33, “Dance of the Double Sun” article by Ken Croswell in ‘Astronomy’ magazine, Kalmback publishing, July 1993.

    That imaged a hypothetical solar system history where an orange dwarf and red dwraf merged to make our Sun and discussed a system of two nearly identical solar twins that were spiralling together and will eventually form one Sirian A type star.

    Interesting read with great space art that if you can still find a copy somewhere. :-)

  33. Rayceeya

    Can anyone remember that classic quote about the “universe being as wonderful as any man can imagine” and even more so. I just can’t think of it right now but this reminds me of it.

  34. Messier Tidy Upper

    @ ^ Rayceeya : Would that be :

    “The universe is not only stranger than we imagine but stranger than we can imagine.”

    By, I think although I could be mistaken, J. S. Haldane, SF writer maybe?

    @22. dave chamberlin : “For a nice stable planet temperature wise and free of pesty asteriods one sun good, two suns bad.”

    I think there is insufficent evidence and reason yet established to draw that conclusion. In Other Words : Not necessarily.

    @28. Chris :

    But wouldn’t the terresterial moons be way too hot? You have 2 sun-like stars heating you up so your orbit would probably have to be about 1.4 times the earths.

    Well that would depend on a few other things like how far out from the stars you were and what sort of atmospheres and greenhouse effects you had if any. The rotation period (day length) might also be a factor as well plus no doubt some other things such as continental positioning, vulcanism level, etc ..

    Wonder if the planet would have cold spells as the one sun eclipsed the other. Also interesting how a society would develop their belief system.

    Not just our mythology either.

    Isaac Asimov wrote a great essay – “Planet of the Double Sun” which is chapter 11 in ‘Asimov on Astronomy’, (Coronet, 1976) – discussing what would happen if our Sun was a binary like Alpha Centauri with another sun orbiting about where Ouranos is -with planets visibly orbiting it. It would clearly demonstrate not all objects orbited earth and would likely speed the advancement of science at least in some respects. Incidentally, Asimov also noted a mythological connection or two there as well withprometheus and of all things, Atlantis.

    Needless to say but I’ll say it anyway – great news and great write-up by the BA here too. :-)

  35. Wzrd1

    @ Jen and Messier, I imagine a MASSIVE thermal pulse that creates MASSIVE turbulence in any cloud present, said turbulence creating vortices that create planets…
    If said protoplanetary masses could exist is depentant upon resonance and other bodies.
    Frankly, you tend to try to model, I think it through, models either work or error, I “see” what may well be. I can’t do a lot of really basic math, but can “approximate’ REALLY large numbers. I “see’ relativity in workable terms, most need computers. MY numbers normally approximate what is arrived at by computers.
    Farked if I know HOW it works, but it does.
    I only know that I see models as they are, no idea HOW it works, but it works out. I SEE things in multiple dimensions normally and it works out over time.
    Naked singularities? I wash my socks in them, but I’d not try a shower OR bath in them.
    Tunneling? No biggie! Can’t figure out THEIR math, but the end product is arrived at.
    Higgs? Fardled if I know, but, it’ll work out in time… Vacuum metastability, of fardling course! How ELSE is there matter over anitmatter!
    Time? If space exists, time MUST exist. Space cannot exist without time, they’re linked, else we’d not have a universe.
    But then, I’m the weird guy who can’t call off multiplication tables and has grave difficulties with the months of the year, yet can blow off general and special relativity as simple as tying my shoelaces.

  36. Messier Tidy Upper

    Isaac Asimov wrote a great essay – “Planet of the Double Sun” which is chapter 11 in ’Asimov on Astronomy’, (Coronet, 1976) – discussing what would happen if our Sun was a binary like Alpha Centauri with another sun orbiting about where Ouranos is -with planets visibly orbiting it. It would clearly demonstrate not all objects orbited earth and would likely speed the advancement of science at least in some respects. Incidentally, Asimov also noted a mythological connection or two there as well with the legend of Prometheus and, of all things, Atlantis.

    Additionally, Isaac Asimov also describes a similar hypothetcial situation could well occur if Venus as well as /instead of Earth had a moon like our Moon in ‘The Tragedy of the Moon’ (Mercury press, 1972, 1973) which is another book I’d highly recommend.

    *****

    “The triple triumph of the Moon, then, is that it made it possible for man [sic] to exist; it made it possible for him [sic] to develop mathematics and science, it made it possible for him [sic] to transcend Earth and conquer space.”
    - Page 38, ‘The Tragedy of the Moon’, Isaac Asimov, Mercury Press, 1972.

  37. Nekura

    I am wondering, it seems logical that the planetary orbital plane and stellar orbital plane would most likely be co-planar, so wouldn’t known eclipsing binary stars make excellent candidates to track for transiting planets?

    Also, what is the distribution of orbital periods for binaries? Since close orbiting binaries could have stable circumbinary planets in their habitable zones, while far orbiting binaries (for example, out around the distance of Pluto) could each have stable planets in their respective habitable zones (provided the orbits of the stars around the barycenter isn’t too eccentric), which is more likely? Edit: These appear to be called “p-type” and “s-type” orbits, according to wikipedia.

  38. Linda

    The sunset in “Pitch Dark,” that is my favourite epic sunset. Or eclipse, rather.

  39. Dave @20: that’s some of the most concentrated non-science I’ve seen for some time. Googling “Comet cluster” tells me all I need to know: references to Elenin, Nibiru, abovetopsecret…

  40. Firemancarl

    @Darth, I was thinking the moon Yavin IV!

  41. andy

    Have to wonder if there are any circumtriple planets out there. There are some very compact triple systems which could conceivably have orbiting planets in outer orbits, including a couple of triply-eclipsing systems discovered by Kepler (KOI-126 and HD 181068). These systems might prove quite challenging for planet hunters however.

    (I guess it is also possible to consider circumquadruple planets as well. The most compact quadruple known is the system VW Leonis Minoris with an outer orbit of 355 days: the inner binaries are a 0.48-day contact binary and a 7.9-day detached pair)

  42. Wzrd1

    @Andy, #41, there are. 16 Cygni B is one, there will be more detected as time goes on. HD 188753 Ab was thought to be another, but has not been confirmed yet (in spite of repeated observations of the system).
    Indeed, due to the proximity of the two stars orbits (12.3 AU, as I recall), planetary formation would be problematic beyond 1 AU, to oversimplify it by a lot.

  43. (See 20. Dave for context)
    Snowball Solar System (SSS) is the only model to offer a comprehensive explanation for the extreme axial tilts of Venus and Uranus along with the small sizes of Mars and 4 Vesta in the context of ‘orbit inflation’, so until a degreed scientist offers an alternative, it should stand.

    SSS is the only model to offer a comprehensive explanation for the volatile depletion of the terrestrial planets, the granite problem, the gneiss-dome problem and the dolomite problem, all as a wind down of our hypothesized triple-star origin.

    SSS is the only model to offer a comprehensive explanation for the three distinct comet reservoirs: the Kuiper Belt and the inner and outer Oort clouds.

    SSS suggests that oil and coal (impacts causing pyroclastic flows that bulldoze forests, resulting in terrestrial fossils in coal cyclothems) are endothermic chemical reactions (ECRs) of methane comet ice, and that theses ECRs clamp the impact-shock-wave pressure below the melting point of terrestrial target rock, obscuring the impact signature of icy comets, (i.e., no suevite melt rock).

    Finally (for now), SSS explains extinction events as caused by the blanketing effect of compound-comet ring-debris impacts (like the rings of Saturn), with boulder fields (Ringing Rocks) and comet impact-slag meterowrongs (containing metallic native-iron blebs) as evidence.

    Granted, SSS is at present only a conceptual model slowly spiraling in on the truth which is at its core, mathematical.

  44. Chris Winter

    Pablo wrote: “It would be fascinating to speculate on a civilization evolving on a planet that later got ejected from its home system. A planetary space ship. Gotta be a novel in there somewhere.”

    George R. R. Martin’s The Dying of the Light concerns a rogue planet that passes near a star, whose light makes it briefly livable. The galactic elite hold a ten-year festival on the planet during this period.

  45. andy

    @Wzrd1, #43: None of those are circumtriples: they are instead in S-type orbits around one member of a triple star system (in all known cases so far, it is the distant tertiary that is the planet host rather than the inner binary).

  46. TheAnt

    Er hello, Kepler 16b was NOT the first planet found circling 2 stars at the same time. This time you do a bit of bad astronomy yourself by repeating the mistake repeatedly made in US media.

    Kepler 16b were the second (or third found). Both the others were in somewhat more distant orbits and and one were really distant – both found by the transient method.
    One of the annoucement were from data by the French Corot,
    And the other were found about 1½ year earlier than Kepler and I have not seen the announcements had been retracted.

    Yet I agree that there’s so many annoucements it is hard to keep track.
    Sciencedaily.com reported on the first planet so it should be possible to dig up the correct facts.

  47. Messier Tidy Upper

    @42. andy :

    Have to wonder if there are any circumtriple planets out there. There are some very compact triple systems which could conceivably have orbiting planets in outer orbits, including a couple of triply-eclipsing systems discovered by Kepler (KOI-126 and HD 181068). These systems might prove quite challenging for planet hunters however.
    (I guess it is also possible to consider circumquadruple planets as well. The most compact quadruple known is the system VW Leonis Minoris with an outer orbit of 355 days: the inner binaries are a 0.48-day contact binary and a 7.9-day detached pair)

    This site :

    http://www.solstation.com/orbits/cas-absys.htm

    suggest possible stable planetary orbits in the six star system of Castor (Alpha Geminorum) with more info on the stars in question here :

    http://www.solstation.com/stars2/castor6.htm

    Multiple star systems tend to be heirarachial, ie. in certain organised relationships. For example, where for example one star orbits outside of two close ones or two pairs of stars orbit each other and there seems to be room for planets to orbit either one pair or the other or around an individual stars orbiting the other two for instance although, of course, it depends on the specifics of each stellar system.

    There was actually an excellent anthology of short stories I recall reading set around a hypothetical earth-sized moon orbiting the red dwarf components of Castor! This came out of an SF writers workshop in 1975 and was titled ‘Medea : Harlan’s World’ with stories by Hal Clement, Fred Pohl and Frank Herbet among others . Link with a little more info on that here :

    http://www.librarything.com/work/199354

    That anthology was one I really loved reading personally & would highly recommend. :-)

    Incidentally, pretty sure I recall reading at least one astronomy magazine article about a binary or multiple star that had a proto-planetary disk detected around it.

  48. mfumbesi

    I thought about standing on an Earth sized moon and seeing the suns set behind the gas giant, before I even read your last comment.

  49. Nigel Depledge

    Why Tatooine and not Magrathea?

  50. Nigel Depledge

    @ Dave (20) -

    You’ve lost me. What SF novel was that from?

  51. Nigel Depledge

    MTU (35) said:

    By, I think although I could be mistaken, J. S. Haldane, SF writer maybe?

    J.B.S. Haldane was a population geneticist.

    He is famously quoted as having said “My own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose.”

    Also from Wikipedia:

    He is famous for the (apocryphal) response that he gave when some theologians asked him what could be inferred about the mind of the Creator from the works of His Creation: “An inordinate fondness for beetles.”

    Was this, perhaps, the person you were thinking of?

  52. Nigel Depledge

    Dave (44) said:

    Snowball Solar System (SSS) is the only model to offer a comprehensive explanation for the extreme axial tilts of Venus and Uranus along with the small sizes of Mars and 4 Vesta in the context of ‘orbit inflation’, so until a degreed scientist offers an alternative, it should stand.

    No, it shouldn’t stand. In most cases, “we don’t know” is a better answer than a meaningless word-salad.

    SSS is the only model to offer a comprehensive explanation for the volatile depletion of the terrestrial planets, the granite problem, the gneiss-dome problem and the dolomite problem, all as a wind down of our hypothesized triple-star origin.

    But the triple-star origin is fantastical. And, moreover, impossible to test, which makes it Not Science.

    SSS is the only model to offer a comprehensive explanation for the three distinct comet reservoirs: the Kuiper Belt and the inner and outer Oort clouds.

    Currently, IIUC, the existence of the Oort Cloud has yet to be demonstrated. It is still a hypothetical construct. True, one with good reasoning behind the hypothesis, but still lacking evidentiary support. Therefore, to feel a need to explain two Oort clouds is, at best, premature.

    SSS suggests that oil and coal (impacts causing pyroclastic flows that bulldoze forests, resulting in terrestrial fossils in coal cyclothems) are endothermic chemical reactions (ECRs) of methane comet ice, and that theses ECRs clamp the impact-shock-wave pressure below the melting point of terrestrial target rock, obscuring the impact signature of icy comets, (i.e., no suevite melt rock).

    What gibberish. The formation of oil and coal are well understood, and require no methane comet ice (BTW, postulating a methane source for coal and oil bizarrely fails to explain the high sulphur content).

    Finally (for now), SSS explains extinction events as caused by the blanketing effect of compound-comet ring-debris impacts (like the rings of Saturn), with boulder fields (Ringing Rocks) and comet impact-slag meterowrongs (containing metallic native-iron blebs) as evidence.

    Words fail me. It looks like they have failed you, too.

    Granted, SSS is at present only a conceptual model slowly spiraling in on the truth which is at its core, mathematical.

    AFAICT, SSS is, at best, highly speculative or, at worst, nonsense.

  53. Good dog Nigel, Waggy tail and beg is how you’ll act when the Curiosity Rover (Arf Arf) discovers a granite comet core in the center of Gale Crater.

  54. Peter Davey

    Some of you may have read Hal Clement’s “Cycle of Fire”, in which a planet possesses two different atmospheres, and ecologies, at different points in its orbit, as the amount of solar radiation changes.

    More recently, Poul Anderson wrote “Fire Time”, about a planet in a system which has two suns, a primary and a secondary, and has two ecologies, one native to that world, the second carried across by the inhabitants of another planet,which orbitted the secondary sun, and was destroyed by the interactions of the two suns millennia previous.

    I think we may be back to Professor Haldane and his comments (Stephen Jay Gould wrote an article on Haldane in one of his later books, although I am afraid that I cannot remember which one).

  55. As to the question of why an Alien Civilization would visit us:
    Really, for a civilization capable of reaching out planet , their technology would be very very far ahead of ours, perhaps by thousands, even millions of years. It is safe to say that they would have a plan for invading / exploring a planet. Careful selection, perhaps by the infamous but elusive dyson sphere group or similar, would track and monitor a planet for the home civilization for years and years simultaneous to other interesting planets of intrigue. Of course they would not go to a planet that had a dangerous atmosphere relative to the life in interest of the said planet, but they might be compelled to explore its chemical plant matter…. like our opium poppy , perhaps one of the most important plants on earth. What other pharmacological wonders do other planets hold for Earth/Humans? I am willing to bet my life that Earth has produced just one, average way of plant life, and that other planets hold spectacular finds for us.

  56. Nigel Depledge

    @ Dave (55) -
    Quite obviously, you have no answer. Parody has a place, of course, but your SSS malarky is a parody of science, not actual science.

    However, I think it is worth noting that I was being polite, whereas you seem to have descended to abuse.

    SO : Either put up or shut up.

  57. Nigel Depledge

    @ Brandon (57) -
    So, what are you saying, exactly, then? That aliens have visited but only came for opium? Or what, exactly?

    BTW, I don’t think the opium poppy even makes the top ten list of most important plants.

    Rice, wheat, corn, potato, cassava, cotton, flax, tea, coffee and the beans from which tofu is made all probably outrank opium in importance.

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »