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Space Science

Kepler Discovers 'Phantom' Exoplanet 78

Posted by timothy
from the from-whence-comes-unobtanium dept.
astroengine writes "The Kepler space telescope has spotted an extra-solar planet with a very odd orbit. Sometimes Kepler-19b slows down by five minutes during its 9-day orbit. Other times it speeds up by five minutes. Johannes Kelper's laws of orbital dynamics never said a celestial body can arbitrarily speed up and slow down; another planetary body must therefore be gravitationally acting on Kepler-19b. Enter Kepler-19c, a world that hasn't been observed, but its gravitational effects have. This is an unprecedented discovery, one that could potentially be used in multi-planetary star systems to discover more 'phantom' worlds that would have otherwise gone unnoticed."
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Kepler Discovers 'Phantom' Exoplanet

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  • Unprecedented? (Score:5, Insightful)

    by Jaryn (880486) on Saturday September 10, 2011 @01:48PM (#37363172)

    Unprecedented? Isn't this pretty well the way we discover all extra-solar planets? Through star wobble? Unless we're lucky enough to line up for a full on occlusion?

    I mean, I guess in this case it's "planet wobble". But FTFA: "Interestingly, planets in our solar system have been detected through a similar method."

    So uh... unprecedented?

    • by Anonymous Coward

      Most of the exo-planets discovered so far have been via the transiting method (this is what Kelper uses).

      Uranus was discovered due to unexplained perturbations in the orbits of the other outer planets. So, not "unprecedented" for our solar system.

      • by dryeo (100693)

        Actually it was Neptune that was discovered by observing Uranus's orbit. Interestingly Pluto was also found the same way, yet it turns out that Pluto is much too small to cause the observed orbital perturbations.
        There may yet be a large planet out there as a 150 years ago it seems that Uranus's orbit was more perturbed then now.

        • by AmigaMMC (1103025)

          Actually it was Neptune that was discovered by observing Uranus's orbit.

          What? Nobody has posted the usual Uranus/Futurama joke yet? People o /. are getting old and slow ;)

          • by tehcyder (746570)

            Actually it was Neptune that was discovered by observing Uranus's orbit.

            What? Nobody has posted the usual Uranus/Futurama joke yet? People o /. are getting old and slow ;)

            There's an eccentric objerct in Uranus. Best get to a hospital.
            Now someone can post the "it's now called Urectum" bit OK?

        • Actually, they found the cause of the perturbation.
          Somebody went through the century-old maintenance logs of one of the telescopes involved in the Neptune measurements (I believe it was Yerkes, but don't quote me on that), and discovered that during a series of nightly observations of Neptune's orbit, some technician had removed the equatorial mount gears for either cleaning, maintenance or replacement, and that should NOT have happened, as the calibration goes a little bit out of sync.
          Therefore, Planet X w

        • by RockDoctor (15477)

          Actually it was Neptune that was discovered by observing Uranus's orbit.

          True, but there were errors in all of [the input data, the methods used, the calculations performed] which if done correctly would have predicted the position of Neptune differently to where the planet actually was. So although the discovery followed the calculations, it was essentially discovered accidentally.

          Analogy : I form the hypothesis that people with blue trousers often drop their wallets when walking down the high street. I f

      • by RockDoctor (15477)

        Most of the exo-planets discovered so far have been via the transiting method (this is what Kelper uses).

        KePLer may well have the numerical advantage by now, but the precedence for the techniques certainly goes to orbital timing, not occultation or spectroscopy.

        Uranus was discovered due to unexplained perturbations in the orbits of the other outer planets.

        No it wasn't. Oh, it's an AC ... well I'll respond to one of the other people.

      • Most of the exo-planets discovered so far have been via the transiting method (this is what Kelper uses).

        Uranus was discovered due to unexplained perturbations in the orbits of the other outer planets. So, not "unprecedented" for our solar system.

        ...
        3. The method of claim 2, further comprising: the star around which the planet orbits is not Sol

        Seems they could apply for a patent.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      From TFA:

      This is the first time that an "invisible" exoplanet has been discovered through its gravitational influence on another exoplanet.

      So that's the exact criterion that makes it unprecedented.

    • by Baloroth (2370816)
      Yes and no. It sounds like it's the same basic technique, but one order removed. Instead of observing the stellar wobble to find the planet, we observe variations in the stellar wobble, and from these observations we notice that there must be yet another planet that is affecting this planet's effect on the sun. So we are using indirect observations on a planet to create indirect observations of a different planet. Not entirely unprecedented, but difficult. It would be like observing Jupiter to find Saturn,
    • by arisvega (1414195)

      Isn't this pretty well the way we discover all extra-solar planets? Through star wobble?

      No, it is not.

      But for sure if the star wobbles, then it is a candidate host for planets.

      Other methods are then used in conjunction with this one. Or, transits are detected first and then one takes a look for wobbling.

  • Not 'unprecedented' (Score:3, Informative)

    by bennetts2 (3638) on Saturday September 10, 2011 @01:54PM (#37363202) Homepage

    This is an unprecedented discovery

    Er, no. Neptune [wikipedia.org] and Pluto [wikipedia.org] were both discovered because of the perturbations they caused of the orbit of Uranus.

    • by nedlohs (1335013) on Saturday September 10, 2011 @02:10PM (#37363300)

      They aren't exoplanets, and hence not a precedent.

      • They aren't exoplanets, and hence not a precedent.

        Depends on your reference frame!

        • by nedlohs (1335013)

          Nope.

          The Solar System is a specific place and not just the star system you happen to be in (well it does happen to be the one you are in right now, but assuming you managed to get to different one...).

          • Nope.

            The Solar System is a specific place and not just the star system you happen to be in (well it does happen to be the one you are in right now, but assuming you managed to get to different one...).

            You Earthlings are so Earth-centric. Everyone knows my solar system is closer to the center of the universe!

            • by Urkki (668283)

              It doesn't matter. Every devout Muslim should do all their calculations in the reference frame of Mecca, every devout Catholic in the refrence frame of the Pope, and every devout Apple owner in the reference frame of Steve. Others should choose equally suitable centre of universe, and stop being hypocrites when doing math.

              • Due to the expansion of the universe, the center of the universe is also getting bigger. This means that bits of it sometimes squeeze out through the smaller dimensions in unlikely places, much like Vegemite through a Sao biscuit.
      • They aren't exoplanets, and hence not a precedent.

        You sound a bit like a patent attorney explaining why something isn't prior art. We have found exoplanets by star wobble and solar planets by planet wobble, I think "unprecedented" is an overstatement, just my opinion. The method was certainly used previously in this system.

    • by Anonymous Coward

      Have you read your links? It says that Pluto's discovery was a coincidence.

      Lowell had made a prediction of Planet X's position in 1915 that was fairly close to Pluto's position at that time; Ernest W. Brown concluded almost immediately that this was a coincidence, a view still held today.

      • by rossdee (243626)

        And anyway, Pluto is not even a planet these days

      • by RockDoctor (15477)
        Tombaugh's job (paid work, for a skilled amateur astronomer) was to carry out a comprehensive photographic survey of the whole ecliptic with at least 2-fold coverage. The 2-fold coverage allowed the use of blink comparametry. The "whole ecliptic" dictated the time scale (an integer number of years) and strongly influenced the search strategy. At the darkest part of night, images could be made of the anti-sun direction on the sky, several hours apart. Process the plates that night and blink them at the start
  • by Anonymous Coward

    Sounds very much like Saturn's moons Epimetheus and Janus, which interact and exchange orbits periodically.

    http://en.wikipedia.org/wiki/Epimetheus_(moon)#Orbital_relationship_between_Epimetheus_and_Janus

    • Another thing it sounds like is the differences in measured times of the orbits of Jupiters moons from Earth's perspective, which is caused by the finite speed of light. Not sure how that would apply in this scenario though.

    • by tehcyder (746570)
      Me Tarzan, you Janus.

      Mock that with your Futurama quote if you can.
  • Sounds very much like Saturn's moons Epimetheus and Janus, which interact and exchange orbits periodically. Wikipedia article [wikipedia.org]
    • by darenw (74015)

      That's what I'd bet on. Such a situation came to exist among small moons of Saturn. Surely it can happen among larger objects around a star.

  • Binary planet? (Score:4, Informative)

    by gstrickler (920733) on Saturday September 10, 2011 @02:49PM (#37363488)

    +/- 5 minutes in a 9 day orbit is a huge variation. This almost has to be a binary planet system, or planet with a massive moon, or something similar. Enough gravitational force to slow or speed up a planet large enough that we can detect it by transit dimming of it's star 650 LY from Earth, that's either a really light planet, or it's got a massive companion orbiting it. The other possibility is that there is a dark star (white/brown dwarf) orbiting the same star, but we should be able to detect that wobble via doppler shift, so the companion moon/planet seems more likely.

    • Or, it's an alien monitoring station, and those variations are just the stabilizers kicking in to make minor adjustments. They must wonder why it took us so long to notice....

    • by mrtommyb (1534795)
      The interpretation which seems most likely is that there is a planet on an outer orbit which is causing the transit timing variations. For the unseen companion to cause these transit timing variation it needs to be in an orbital resonance with the transiting planet. The most likely orbital period ratio is 4/3 for the two planets. We can rule out any stellar mass companion to the star Kepler-19 because we do not see any stellar wobble - radial velocity variation in the stellar spectrum.
      • Re:Binary planet? (Score:4, Interesting)

        by gstrickler (920733) on Saturday September 10, 2011 @08:58PM (#37365168)

        Perhaps you missed the significance of a +/- 5 minute variance of a 9 day orbit. That's 5/(9*1440) = 5/12960 = 1/2592. That's nearly 0.04% variance in the orbital period of a planet. To achieve that much change in orbital period, the velocity change needs to be at least that great, and likely at least 2x that great (since speed changes won't be instantaneous, it will have to slow down 2x as much to average 0.04% slower orbital rate).

        Given gravity is inversely proportional to the square of the distance between the centers of mass, how much more massive must the other body be to produce that much change in velocity? Even if the other body is in a 4:3 resonance, making it "relatively close", it would still need to be vastly more massive than the observed planet. If it's vastly more massive and in orbit around the same star in a 4:3 resonance, we would definitely be able to detect it by it's doppler shift of the star unless it's orbital plane is almost perfectly perpendicular to our line of sight, and then we would still likely observe an effect on the star.

        The other possibility is that there is a third massive body in the system that playing tug-o-war with the planet, pulling it away from the star, then the star pulls it closer, constantly changing it's orbit. That way the velocity of the planet doesn't have to change as much, however, how such a system could produce such an oscillation in the planet's orbit, sometimes increasing it and sometimes decreasing it resulting in such large changes in orbital period without also causing measurable effects on the star is mystery.

        We may eventually figure it out, but for now, that much variation in orbital rate is really bizarre.

    • Re:Binary planet? (Score:4, Interesting)

      by DG (989) on Saturday September 10, 2011 @08:43PM (#37365120) Homepage Journal

      That makes me wonder how much energy is being transferred to / from this planet every time its orbit speeds up / slows down.

      I bet it's not the most geologically stable place in the universe - assuming it isn't a gas giant.

      DG

    • by sgt scrub (869860)

      I was picturing a binary planet too with a yoyo like orbit. When one of the planets is moving towards us it would look like it was slowing down. When it is moving away it would look like it is moving faster. How two objects could sustain a yoyo type orbit is an interesting thought. Then I started to think about it being more like a liquefied mass that is oscillating. If it is close enough to the sun to have a 9 day orbit it is more than likely the object is molten. Also, the sun could be applying a so

  • I hope this doesn't mean we'll hear more from those Nibiru folks.
    • I hope they do jump on this one. Then we'll see how they try to explain how a planet 650 LY away is any threat to humanity. Even the fastest objects we've detected travel only ~ 250k mph (400k k/h). Let's be very generous and say approximately 1.08M k/h ~ 300 k/s closure rate or about 1/1000 (0.001x) the speed of light. Therefore, it will take at least 650,000 years for it to reach Earth. Oh no, we're doomed!

      • by PIBM (588930)

        They've been on their way since they detected Australopithecus sediba, 649,999 years and 364 days ago, all the while using an invisibility cloak.

        • Except, we're still seeing the effect on a planet that is only 650 LY away, so they were 650 LY away 650 years ago.

          • by PIBM (588930)

            Yep, and that's why I used the Australopithecus sediba reference, as we know they were on earth up to 1.988 million years ago! I could have used the homo erectus, which were well represented from 1.5M years ago to 0.2M.. Anyway =)

            • No matter how you count it, if they were 650 LY away 650 years ago (i.e. we're seeing the effects in starlight now), and they can travel at the outrageous speed of 1/1000 the speed of light, then they're still over 649 LY away.

              • by PIBM (588930)

                They detected it 650LY ago in our system reference, as I made no specific system reference. That means that what they saw was 1.3M years ago here at that point in time. Thats why I was referring to such an old type of homo (xxxxx). And yes, I was considering that their technological advancement allowed them to be both invisible and almost as fast as the speed of light. I'm not sure how you could have missed that ?

                • 650 LY, Not 650,000 LY. 1.3M years ago doesn't come into the picture anywhere. Keep your units straight.

                  We're seeing the system as it was 650 years ago (circa 1360 AD in our reference), therefore, the gravitational effects we're observing mean that there was something there 650 years ago. If it was 650LY away 650 years ago. I started from my explicitly stated premise that the fastest any massive object has been observed to travel is less then 0.001C (actually ~ 0.0004C, then allowed doubled that as a closur

                  • by PIBM (588930)

                    lol yeah, I forgot that I had initially used the parent poster 1/1000 of the speed of light for their speed, not ~speed of light.

      • by Jmc23 (2353706)
        um, wormhole.
  • by TechyImmigrant (175943) * on Saturday September 10, 2011 @02:55PM (#37363520) Journal

    Maybe it isn't another planet. Maybe it's epicycles!

  • "that's no moon"

  • by Anonymous Coward

    First, read the summary. Then read the article. In this article you will see that we have found a planet orbiting a star 650 light years away. The fact that we are able to detect it at all is quite amazing. The advances in optic, the investment in space-based telescope, the ability to process the tons of data that this telescope have produced is plain astounding.

    Then you have to factor in the optic advancement to see this planet directly. Then you realize just how freaking far science has come along. Run th

  • Maybe the planet is slipping out of time because it is so far from the sun, this might explain the speed fluctuations. Perhaps there is an undiscovered solar shelf or drop off into a unknown time dome around our sun. Maybe there is a gravitational dust storm the planet travels through during each cycle. That could be unprecedented or maybe just, unanticipated. :)
  • They have a cloaking device which surrounds the entire planet, and are playing with a huge tractor beam.

  • Hmm...Intresting Disocvery

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