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First Image Of Planet-Like Body Orbiting A Star

Posted by timothy on Mon Jan 07, 2002 10:15 PM
from the won't-be-the-last dept.
Space Science
deglr6328 writes "The Gemini North Telescope has, for the first time, directly imaged a planet like body orbiting a star. The object is a brown dwarf, 55 to 78 times the mass of planet Jupiter and 14 AU distant from its parent star 15 Sge. It was imaged using adaptive optics(see also here) that correct for the blurring effect of the atmosphere using deformable mirrors. Cool!"
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  • Hmmm.... (Score:5, Funny)

    by cporter (61382) on Monday January 07 2002, @10:17PM (#2802219)
    Is that a Starbuck's I can see on the high-res JPEG?

  • Nice link to images, too (Score:4, Informative)

    by Tri0de (182282) on Monday January 07 2002, @10:22PM (#2802241) Journal
    while you're there

    http://astra.hi.gemini.edu/gallery/science/

  • Planet-like bodies (Score:4, Funny)

    by 6EQUJ5 (446008) on Monday January 07 2002, @10:24PM (#2802249) Homepage

    I say we name it "Rosie" or "Oprah"....
  • Well, they say that some 75% of the internet's bandwidth revolves around heavenly bodies.
  • Even though the "photograph" is of just two fuzzy blobs it's cool nonetheless, especially that the first thing photographed should be celestial object that we don't have in our solar system that also happens to simultaneously prove that there have to be numerous ways that solar systems are "born" in the wake of a star's formation.

    One wonders if the cosmic soup had simmered a little more or a little less if Jupiter wouldn't be a binary star. How would it affect sleep patterns? What the hell would our watches look like?

    • Re:Saw this earlier today (Score:4, Insightful)

      by CaptainCarrot (84625) on Monday January 07 2002, @10:47PM (#2802325)
      One wonders if the cosmic soup had simmered a little more or a little less if Jupiter wouldn't be a binary star. How would it affect sleep patterns? What the hell would our watches look like?

      Would we even be here?

      Considering the climactic history of Earth, it's clear that even small perturbations in its orbit and small changes in the brightness of the Sun have large effects on the climate. In a binary star system, its not at all clear that any planetary climates would ever be steady enough to allow higher life forms to develop. Neither the orbit nor the energy received from the suns would likely be stable enough.

      • If Jupiter had somehow been lit (by being hit by an object the size of uranus, say - I've been told that would have done it), it would have burned out in the deep, deep precambrian (billions of years ago). It doesn't have five billion years of fuel. While burning in the early stages of earthly development, it would have been about as bright as the moon (of course, the sun at that time was bluer and overall dimmer). Butterfly flaps it's wings in China, I know, but I don't think it would have been enough of a change in the overall radiation level on earth that whatever conditions allowed life to rise on earth wouldn't have been in effect. Given those conditions, you ask - is life likely to arise, or is it a rare event even in the conditions that favor it (over the course of billions of years,) such that a tiny change in conditions could have prevented that one spark of life from occuring? As a molecular biologist with interests in the field of molecular evolution and structural biology, I'm going to say - no, given that conditions that favor the appearance of life (as a chemical phenomenon) it's going to happen.

        If Jupiter were more massive - simply igniting it without changing it's mass wouldn't cause it to exert more gravity - well, yeah, all bets are off, since that would imply very different things about the environment under which the entire solar system formed. Although, it just occured to me, Jupiter's core is still undergoing nuclear reactions (so is the earth's core) just not on a stellar scale. I don't see how we'd know if those reactions had been much faster/brighter three billion years ago. We'd have to guess from the amount of heavy hydrogen present in the Jovian atmosphere, and I don't think our measurements (radio spectroscopy? something about Jupiter's magnetic properties?)are precise enough to figure that out.

        • Re:Saw this earlier today (long ruminations) (Score:2, Informative)

          by Anonymous Coward
          It's not a matter of whether or not Jupiter gets "lit". The sun was never "lit" as you speak of it. The sun is massive enough that the gravity well in the center is massive enough so that the nuclei of hydrogen particles collapse into helium (and these can collapse into heavier elements; our sun reaches it's limit around Oxygen. heavier elements are made in more massive stars). This collapse of nuclei into heavier nuclei is called fusion (gives off lotsa energy). Now for Jupiter to become a star it would have to be around the order of 100 times more massive than it is now (though that's still much less massive than the sun). With that much more mass it would definately affect the orbits (and possibly even the accretion, as there would have been an planet where the asteroid belt is were it not for Jupiter's current mass) of all the planets.

          Also, the nuclear reactions going on inside the Earth and Jupiter's cores are fission based (decay of unstable elements). This is completely different from what's happening in the Sun so comparing this to what was happening in the early stages of the solar system is pointless.
          • . Now for Jupiter to become a star it would have to be around the order of 100 times more massive than it is now (though that's still much less massive than the sun).

            Well, that may or may not be true. The question is - can you get Jupiter's core under enough pressure to undergo fusion? The fact that it is undergoing fission now is relevant because fission of the sort occuring in Jove's core also requires considerable (although lesser) density/pressure. The heavy elements may also provide a source of high energy alpha particles to help fusion get started (like in a modern H bomb which uses fissioning technitium as a trigger.)

            So, PV = nRT, right? Well, if Jupiter were hit by a uranus-sized object moving perpendicular to the orbital plane -

            1) It would put off huge amounts of heat (q = delta T / S) which might increase the pressure in Jupiter's core enough to ignite it.

            2) The actual impact would involve a lot of force, as well - the whole planet would deform like a ball bouncing off the wall of a squash court. This would constrict the volume available to the core (lowering V, raising P) as well as causing huge differentials in density (raising n locally) as the planet bounced back into shape.

            I'm not sure if that would be enough to do it, but once Jupiter is "lit", the fusion processes in it's core WOULD put off enough heat to be self-sustaining.

            Also, the nuclear reactions going on inside the Earth and Jupiter's cores are fission based (decay of unstable elements). This is completely different from what's happening in the Sun so comparing this to what was happening in the early stages of the solar system is pointless.

            Actually, fusion is decay of unstable elements as well - heavy hydrogen nuclei are hit by other heavy hydrogen nuclei and "decay" into helium nuclei. The fission at earth and jupiter's cores is NOT spontaneous decay like you see in a sample of carbon 14 that is left to sit (at least not mostly). It's collision-mediated decay, a slow form of chain reaction like you see in a detonating U235 bomb. That is to say, like nuclear fusion, the fission that occurs in the earth's core is collision mediated.

            Thank you for pointing that out though, since I agree that my previous post certainly didn't draw a distinction between the two.

              • Re:blowing itself apart? (Score:5, Informative)

                by BadDoggie (145310) on Tuesday January 08 2002, @05:19AM (#2802947) Homepage Journal
                Let me help with your understanding.

                ...the reason that the sun doesn't blow apart is the extreme gravity holds it together.

                The Law of Hydrostatic Equilibrium: Within every layer [of a star], the outward force of pressure equals the inward force of gravity.

                Stars must have M 0.08 Msun to fuse hydrogen.
                There exists a high-mass cutoff because very high mass stars cannot attain hydrostatic equilibrium. Very high mass stars produce enormous numbers of high-energy photons (L and T are both large). Photons exert pressure on gas (an effect called radiation pressure.) Ordinarily, the effects of radiation pressure are small, but for stars with M > 60 Msun, models indicate the radiation pressure is large enough to blow the star apart.

                ...when [stars] run out of fuel, that outward pressure dissapears rather suddenly and everything falls back in.

                When a star exhausts the supply of H (hydrogen) in its core, it becomes a giant or supergiant, depending on its mass.

                Once a star has used up all the H in its core, fusion of H into He (helium) stops. The core starts to contract just as it contracted as a protostar before H fusion began. As the core contracts, it releases energy. This energy heats up the layer immediately above the contracting He core. The layer immediately above the core becomes hot enough to initiate the fusion of hydrogen into helium.

                The star now has three main layers:
                (1) Helium core (inner layer): Releases energy as it shrinks in radius.
                (2) Fusion shell: Releases energy as it fuses hydrogen into helium.
                (3) Hydrogen envelope (outer layer): Absorbs energy, and swells greatly in size.

                These swollen stars are now giants (if M 8 Msun).

                Supergiants and giants with M > 0.4 Msun become hot enough to fuse He into C by the "triple alpha process", making primarily C (carbon), sometimes overshooting and making O (oxygen), and making Be (beryllium) as an intermediary product (and lots of gamma rays, too).

                Once a giant or supergiant begins to fuse He in its core, it has four main layers.

                Supergiants and giants with M > 3 Msun become hot enough to fuse C into heavier elements.

                There is a limit to fusion: Iron (Fe).

                The stages in the life of a 25 Msun star:

                Hydrogen fusion lasts 7 million years
                Helium fusion lasts 500,000 years
                Carbon fusion lasts 600 years
                Oxygen fusion lasts 6 months
                Silicon fusion lasts 1 day
                The star's core is now solid iron: end of the line as far as fusion is concerned.

                Two choices:
                (1) The star finds an alternative pressure source to maintain hydrostatic equilibrium which doesn't rely on the random thermal motions of atoms and ions; or
                (2) The star collapses giving you:
                a) black hole
                or
                b) nova/supernova

                All clear now?

                woof.

                citations/references:
                http://www.sciam.com/specialissues/0398cosmos/0398 starrfield.html
                www-astronomy.mps.ohio-state.edu/~ryden/ast162_4 /n otes16.html
                cse.psc.sc.edu/hses/StarEvol/pages/reds.htm
                blueox.uoregon.edu/~jimbrau/astr122/Notes/Chapte r2 1.html
                www.imsa.edu/edu/astrophys/studentwork/inquiry/ (not as good)

          • > The sun is massive enough that the gravity well
            > in the center is massive enough so that the
            > nuclei of hydrogen particles collapse into
            > helium

            The gravity of the sun isn't great enough to directly override the nuclear forces and cause fusion to occur. The weight of all the sun's material pressing inward because of that gravity, however, is great enough to cause fusion.
        • If Jupiter had somehow been lit ... it would have burned out in the deep, deep precambrian (billions of years ago). It doesn't have five billion years of fuel.

          No. It would outlive the Sun. The larger a star is the greater the internal pressure, and the faster it burns fuel.

          Small stars are long lived, large stars burn out fast.
        • If Jupiter had somehow been lit (by being hit by an object the size of uranus, say - I've been told that would have done it), it would have burned out in the deep, deep precambrian (billions of years ago). It doesn't have five billion years of fuel.

          Usually, dimmer stars burn much longer than brighter stars, so unless the planet-hit/lit-by-some-huge-asteroid is some strange exception, it should still burn today and should all in all burn much longer than the sun.

          • Problem: Jupiter simply doesn't have the *mass* to sustain 5.5x10e9 years of fusion. Its mass is less than 1/1000 the Sun's, and its diameter not 1/10 the Sun's.

            More importantly: a bitch-slap from a passing asteroid will not "ignite" a big-ass ball of H & He. This is astrophysics, here; we're talking about 20000000000000000000000000000000kg of hydrogen, not Strike-Anywhere White-Tip kitchen matches!
            Jupiter is about 1/80 the mass needed for ignition, which occurs due to heating from internal gravitational collapse.

            woof.

            "Ignite Jupiter", indeed! Then again, I once thought you might be able to "execute" a star simply by hitting it with a chunk of iron (see my other post on this thread.)

  • Are they absolutely sure someone didn't sneeze on the lens?

    Nick

  • Whats a Brown Dwarf... (Score:4, Interesting)

    by halo8 (445515) on Monday January 07 2002, @10:30PM (#2802268)
    a Brown Dwarf is said to be Classified Less massive [sciam.com]than stars but more massive than planets,
    brown dwarfs. so.. at 78 times the size of jupiter how massive is massive? and how massive is it not massive compared to a star?

    • Re:Whats a Brown Dwarf... (Score:4, Informative)

      by PhuCknuT (1703) on Monday January 07 2002, @11:04PM (#2802371) Homepage
      A brown dwarf is a star massive enough for deuterium fusion, but not massive enough for normal hydrogen to fuse.
        • The big deal is that this is the first time they've directly observed something this size orbiting so far from a star, it challanges the theories of solar system formation. I may be wrong, but I don't think we've observed (directly or indirectly) anything close planet sized that is more than a few AU from it's parent star.
    • Stars form from collapsing gas clouds. During the collapse, the core will get very dense and hot. However, if the mass is too low, the temperature and density will never reach the point where stable hydrogen fusion will ignite. The critical mass is about 8 per cent of the Sun's mass, corresponding to some 84 Jupiter masses.

      An object below this limit is substellar, and may be either a Brown Dwarf or a planet. The distinction between both is somewhat fuzzy, and certainly to some degree arbitrary. One could argue that Brown Dwarfs and planets differ by their mode of formation - Brown Dwarfs form from collapsing gas clouds, like normal stars, while planets form from accretion of material in a circumstellar disk. However, establishing how a particular object has formed is not an easy task, so this is not a very practical definition.

      Because Brown Dwarfs cool down over time, they eventually become cool enough for dust forming in their atmospheres, and they may show atmospheric phenomena (e.g. dust clouds) similar to those we know from planets. This is one of the reasons why surface imaging, either by direct imaging or with Doppler imaging, would be very interesting.

  • The distance between the substellar object known as brown dwarf and its parent star is less than that between the planet Uranus and the sun.
    Wait a minute, I thought the brown dwarf was 14 AU from its star, not 1 AU. Oh, I see. Sorry for the confusion.

  • Now here's what's funny ... (Score:3, Funny)

    by dmarcov (461598) on Monday January 07 2002, @10:36PM (#2802295) Homepage
    I had a high school physics teacher that was a bit of a bible thumper (no offense to any thumpers out there) who insisted that we would /never/ find planets (or planet like objects)in other solar systems. It was impossible, because . Something about proof denying faith, and without faith God being nothing ... oh wait -- that was someone else.

    I'd love to talk with him now ...
    • Now that god has apparently failed him he is probably off learning how to be a satanist. (typical extremist behaviour)

      --jeff

    • Re:Now here's what's funny ... (Score:4, Interesting)

      by gewalker (57809) <Gary@Walker.AstraDigital@com> on Tuesday January 08 2002, @12:16AM (#2802538)
      Perhaps instead of thumping his Bible, he should have tried reading it before expressing his opinion. The book is silent on other planets and of course life on other planets, much less intelligent life on other planets.

      Perhaps once could infer that there is no intelligent life on other planets based on theological complications with Jesus having to die for their sins too, but even that is speculation beyond what the book says.

      The Bible has very little to say about scientific matters, despite what many theologians and Bible thumpers have decided up over the years. You would think people would have learned that making up stuff, claiming it was based on the Bible, and then getting trashed by the facts would have become unpopular since Galileo. BTW, the theoligians that disagreed with Galileo were following Aristotlean arguments not the Bible. Once again, the bible never says the earth was the center of the universe, etc. The Bible mentions the sun rising, etc. and people have inferred that the earth is at the center becuase of such language -- however, this is merely descriptive of the apparent sunrise, I can even read the sunrise & sunset times in the morning paper, and I am pretty sure that publisher know that earth orbits the sun, and the sun-rise is simply appearance, not a literal sun-rise.

      Back to topic

      Let's face it, the ability to directly image anything outside the solar system is pretty amazing. It was not very long ago that Betelgeuse was imaged as the first star (as a disk, not a point source).

      There are some very interesting large-baseline telescopes that have been proposed that would theoretically allow imaging details of planets in other solar systems, alas they budget for such projects may be some time in coming.

      It's still a long way to the nearest star. With current tech, would be be very lucky to get a large ship moving at 1 percent light speed, so we will have to settle for pictures for some time to come. Where is Zephran Cochran when you need him?

  • ummm, excuse me... (Score:5, Informative)

    by anzha (138288) on Monday January 07 2002, @11:16PM (#2802405) Homepage Journal

    What ever happene dto Gliese 229?

    That was imaged back quite a while ago by a caltech team.

    I found papers about it at Jean Schnieder's webpage [obspm.fr], but not a listing...

    • Re: Mod up. (Score:5, Informative)

      by deglr6328 (150198) on Monday January 07 2002, @11:38PM (#2802461)
      Someone needs to mod the above up; it's important. I would have rephrased the post to reflect that this was NOT the first image of a brown dwarf orbiting a star if I knew about it before I submitted the comment.

      On closer examination, the Gemini North press release [gemini.edu] does not claim to be the first to image a brown dwarf; from the site:"The faint companion is separated from its parent star by less than the distance between the Sun and the planet Uranus and is the smallest separation brown dwarf companion seen with direct imaging". It is only the CNN story that incorrectly claims this.....Hmmmm perhaps a notification [badastronomy.com] is in order.
    • You mean Gliese 229B... Gliese 229 is the parent star. :-)=

      And yes, that was the first direct image of a sub-stellar object outside the Solar System. CNN's science writers could use a clue.

      [TMB]
  • Until we see it moving around that other star in an ellipse, it's just some bright pixels next to some other bright pixels. Hopefully, in a few months, we'll get to see some relative motion from it.

  • Telescopes have improved (Score:4, Informative)

    by oni (41625) on Monday January 07 2002, @11:25PM (#2802427) Homepage
    I still have a high-school science book that states "a star will appear as a single point of light even in the largest telescopes"
    Now we can see surface features on stars and even objects orbiting them. Pretty cool. Imagine what an orbiting interferometer will do!

    • Re:Telescopes have improved (Score:4, Interesting)

      by supernova87a (532540) <<kepler1> <at> <hotmail.com>> on Tuesday January 08 2002, @02:28AM (#2802778)
      Well, an important thing to understand is that this discovery is not a "picture" of the planet or the star in the traditional sense, in that you cannot see details on the surface of either the planet or star. That possibility is simply way beyond any telescope technology we currently have, and will continue to be for quite some time.

      If you take a look at the original image released (in the CNN story), the point is that the scientists were able to see the planet separately from the star, on its own, for the first time. Up until now, it has generally only been inferred that those planets exist, based on the wobble of the parent star, or appearance/disappearance of elements in the spectrum.

      Both the star and the planet are point objects. There is no detail you can see on either, even though they seem to have "diameter". This is just diffraction at work.
  • ...Won't someone go to the effort of making a pun involving the words "brown dwarf" and "uranus"!

    I am almost certain it can be done. Someone out there must have the technology.

    :)
  • As you can read, as far as 1995, the Hubble Space Telescope imaged a brown dwarf orbiting a brown dwarf on Gliese 229B [stsci.edu]. Indeed, some of the US media call it "the first discovered brown-dwarf" although the discoverer was Rafael Rebolo et al at the Instituto de Astrofísica de Canarias [www.iac.es] (he and his colleagues proposed the "Lithium test" method to actually detect this substellar objetcts). You can read a short report about brown dwarf findings at American Scientist [sigmaxi.org].

  • huble space telescope obsolite? (Score:4, Interesting)

    by autopr0n (534291) on Tuesday January 08 2002, @12:50AM (#2802602) Homepage Journal
    adaptive optics have the ablity to create images at the same resolution of the Huble space telescope. I wonder what this means for it's future. Seems kinda pointless now.

    ( I submitted an artical about it to slashdot a month or so ago, but it was rejected..)

    • Re: Hubble Space Telescope obsolete? (Score:4, Informative)

      by Gogo Dodo (129808) on Tuesday January 08 2002, @01:46AM (#2802703)
      The HST was built in the late 70's/early 80's. When did adaptive optics start up? I imagine that at the time, the HST was cutting edge for non-military space telescopes.

      As for the HST's future, it's scheduled for EOL at the end of the decade. Check out NASA's Next Generation Space Telescope [nasa.gov] page for its successor.

    • Re:huble space telescope obsolite? (Score:4, Informative)

      by TMB (70166) on Tuesday January 08 2002, @12:34PM (#2804475)
      There are a few advantages that HST still has...

      - AO works by measuring the distortions in the atmosphere and then compensating for them. But light from different parts of your field take slightly different paths through the atmosphere, and so are not perfectly corrected. As you get farther and farther away from the point where you measured the distortion, your corrections get worse and worse. The amount of sky that you can correct at once is quite small.

      - In order to measure the distortions, you need a bright star that you can take as a point source. So bright that only about 1% of the sky is accessible. Artificial stars are still unreliable (but getting better).

      - AO-corrected images have a really weird point spread function (PSF)... you have a fairly large halo of light around a sharp peak in the centre. Great for finding points, but hard for measuring how bright the entire thing is.

      - The atmosphere blocks out a hell of a lot of the UV and IR light. No way of getting that back without going above the atmosphere.

      So HST still has very unique capabilities. And just wait until we start seeing science out of the ACIS instrument!

      [TMB]

  • So... (Score:4, Funny)

    by Simon Garlick (104721) on Tuesday January 08 2002, @01:07AM (#2802629)
    They're admitting that it's all done with mirrors?
  • The object is a planet, 1/55 to 1/78 the mass of a brown dwarf. View the photo [nasa.gov].

    -
  • the abstract for the technical article is already on the preprint servers. it's much better than the cnn article, for the technically trained. (the complete article was temporarily withdrawn, but they tell you how to get it.) see http://xxx.lanl.gov/abs/astro-ph/0112407

  • Be polite - be politically correct! (Score:4, Funny)

    by Hektor_Troy (262592) on Tuesday January 08 2002, @04:29AM (#2802890)
    African Extraterrestrial Vertically Challanged Star
  • An actual image of a planet-like body orbiting a star? No way! [bnsc.gov.uk]
    • This is the first planet seen outside the solar system, okay? Previously we'd been able to detect planets through other means (ie a larger planet's gravitational influence on its star) but now it seems we've been able to get an actual visual of one. That's why this is news.

    • Well...neither really (Score:4, Informative)

      by xX_sticky_Xx (526967) on Monday January 07 2002, @11:03PM (#2802370) Homepage Journal
      Like the article says, brown dwarves cannot be considered stars since they do not generate energy from a thermonuclear reaction. Having said that though, they DO give off more energy than they receive from outside sources, much like Jupiter does but on a far larger scale. A good primer site for brown dwarves can be found here [bahnhof.se].

      Lastly, it is important to not confuse brown dwarves (almost stars) with white dwarves (dying stars).
      • Brown dwarves occupy the lowest mass regime of all the stars. For example, the largest stars known weigh about 50x our sun's mass, and the smallest stars weigh 0.08x our sun's mass.

        As correctly stated above, the definition of a star (ie. from 0.08 to 50x the sun) is something that's undergoing fusion in the core, which is the energy source for the star.

        The reason that brown dwarfs (and Jupiter) don't become stars is that when they initially formed out of condensing gas, there was not enough material (and thus enough mass) to generate enough pressure at the center of the body to start nuclear fusion. Only when there's high enough pressure, temperature, and density can a star begin fusion. And gaseous bodies with less that 0.08 our sun's mass can't do this, by the laws of hydrostatics (static fluid calculations). Hope this helps!
    • The mass is deceptive.
      The body is closer to the size of the Sun than Jupiter.
      Still brown dwarves are important to study and may be very common in the universe.
    • Oh never mind, I won't bother. I was going to try to explain the significance of space research, etc. For one thing, Galileo was one of the first to challenge that the Bible does not have to be the be all end all of science, and that man can learn more on his own by observing. Without telescopes and people looking at stars, we would be alot far behind where we are today, and who knows where it will bring us. It just might help unify the people of the earth some day, and then you'll be the fool for telling us it was foolish of us to discuss such things when people are dying.

      By the way, while you are on your campaign to protect innocent lives, you better take on drunk drivers, pollution, serial killers, cigarettes (maybe not innocent, but still..) AIDs victims (especially in '3rd world countries'), etc. You better get moving.

    • Re:I've gone colour-blind! (Score:2, Funny)

      by Anonymous Coward
      I can't believe that scientists are still using terms like "brown dwarf". Am I the only one that forsees a protest by african american and vertically-challenged groups? :)
    • so they drew it in, right? i can do that too! look, planets!

      It is not quite that bad. This link here is really nice [llnl.gov]. I'm putting in a plug for my old alma-mater (go slugs.)

      Yeah, the pictures are pretty (awesome, if real) but I'm going to wait for pictures from the Hubble (which had better be forthcoming!) before I'm totally persuaded.

      That said - 58 light years? That's a long trip, but totally possible.

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