PLANET IMAGED AROUND A SUNLIKE STAR?!

By Phil Plait | September 15, 2008 9:07 am

Is this it? Is this the very first image of a planet orbiting a star like the Sun?

Planet orbiting a sunlike star?

The image come from the monster 8 meter Gemini North telescope in Hawaii. The star is 1RSX J160929.1-210524 (for those taking notes at home) — it’s a K7 dwarf, a bit cooler and smaller than the Sun — and the planet is the blip circled at the upper left. It has no real name as yet — it hasn’t been confirmed yet; more on that in a sec — but if it’s a planet orbiting the star, it has a mass of about 8 times that of Jupiter.

The image is in near-infrared, just outside the human range of vision. This is a good place to hunt for young planets, because for millions of years after they are formed, planets are hot and glow in the infrared, while stars like the Sun are faint in the IR. Well, relatively faint; they still pour out energy, but it’s a lot less than in the visible part of the spectrum. So using IR detectors means you’re looking where young planets put out most of their light, and stars put out the least.

The planet seen by Gemini appears to be about 5 million years old– the parent star is part of a cluster of stars whose age is known. They lie about 500 light years from Earth.

Spetcra of the potential exoplanet. Click to enlarge.
Spectra of the star and planet. Click to embiggen.

The reason astronomers think this is a planet is because they took spectra: they broke the light up into a rainbow, if you will, and when you carefully examine the spectrum you can determine all sorts of things about the object emitting the light: how hot it is, what chemical composition it has, how old it is, even if it’s spinning!

The spectrum of the object matches that of an old, very low mass star. That might make you think it’s a star, but wait! The planet is young, and still hot. The light it gives off depends on its temperature, so a young low mass object, like a planet, can look just like a more massive object like a star. Since we know this object is young, we know it has a lower mass than its spectrum naively suggests. When models of how planets cool are used, we get a pretty good match for one with 8 times Jupiter’s mass if it’s the age of the star cluster, 5 million years.

But this is not confirmed! For example, it could be a low mass star that happens to be near the other star along our line-of-sight — in other words, it’s in the background. The best way to see if that’s true is to wait a year or two and take more images. If the object moves against the background stars along with the brighter star, then it must be physically associated with the star, and therefore it’s a planet. This is how we confirmed the first image of an exoplanet back in 2005 — but that was orbiting a brown dwarf, a star very different than the Sun.

If confirmed, this one is pretty important, because the parent star is much like our own Sun. The most interesting thing about this is the distance of the purported planet from the star: 50 billion kilometers! That’s 11 times the distance Neptune is from the Sun. And that’s a lower limit; it might be farther. That makes me very suspicious: we don’t know of any way to form planets that far from their parent stars.

Stars and planets form from rotating disks of gas and dust. The stuff collects in the middle to form the star, and the stuff farther out forms the planets — we have seen many examples of this in the sky. The disks we see around new stars are big, sure, but by the time you get 50 billion km out they are very thin, and there’s just not enough material out there to form a planet, let alone one with 8 times the mass of Jupiter.

In this case, the most likely explanations for this image are that 1) this isn’t a planet, but a background star, or 2) it formed closer in and was ejected by an encounter with another planet, moving it way the heck out from the star. (1) is a bummer, and is unlikely just due to statistics; it’s isn’t high odds to see an object like this by coincidence so near another star. (2) seems unlikely to me as well; it’s hard to toss around a planet that mass unless an even more massive planet was involved. I hope this star is a target for searches for more planets, just to get more information on this scenario.

To their credit, the astronomers involved are also clear about this in their paper announcing the discovery. This is a carefully done observations, and they are appropriately careful in their announcement.

But if it’s true… WOW. This would be the second planet ever seen directly in an image, and the first to orbit a star like the Sun. The implications would profound. It would be direct evidence of planets orbiting other stars at great distances. It would mean there could be another planet in our own solar system (unlikely, but I’ve written about that before). And it would mean that it’s possible to use this method of near-infrared mapping to actually get pictures of more planets! Seeing one might be a fluke, seeing two means there are more to find.

The next clear night, do yourself a favor: go outside. Look up. See all those stars? Whether or not this particular planet pans out, we still know that a large fraction of those stars — 10%? 20? — may have planets. And some fraction of those may have planets like Earth orbiting them. We really weren’t sure about this even 15 years ago, and now we’re able to not only start plugging numbers into the equations, but we can actually take pictures of some of these objects.

My oh my. How I do love science.

Comments (90)

  1. Come on now Dr Plait, this is unconfirmed. ;) No reason to get all excited about it. :P

    OMFSM!!!!!!!! That is sooooooo freaking COOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    Oops! I got excited too!

  2. Pete G

    Oh Wow. That’s fantastic, to have an actual photograph of the planet itself. That’s one huge, (and young) planet too.

  3. This is a very exciting development! I do hope the distance issue is just a fluke, though.

  4. GK4

    I am one of those who take notes at home. So, what is the abbreviation at the beginning of this star’s designation? I don’t recognized “1RSX”. And what does the “J” mean?

  5. Michelle

    Schweet! Man, that’s so cool. I’d like to see religion give us cool things like that.

    Countdown to medias saying something about possible life found around other stars in 3…2…1…

  6. In the midst of war and economic collapse you give me something to smile about. BA FTW.

  7. Nice post, Phil. I am reservedly enthused by the discovery.

    I bet the press will announce it as the first photograph of a new planet orbiting a sun-like star.

  8. John

    I don’t know if ejection is all that unreasonable. Given that we need a migration mechanism to get solar systems like those observed with RV methods to look like our own, extrapolating that migration mechanism to cause the occasional ejection seems ok to me. Especially since the system is young, it might not have completely dynamically relaxed yet.

    Nevertheless, this is quite amazing if it is born out to be true.

  9. Manveet

    Really, really cool stuff.

    I think the only thing that could top this would be if someone actually found a planet extremely similar to earth. Correct me if I’m wrong, but the vast majority of exo-planets discovered have been gas giants similar to Jupiter and Saturn in our solar system. I believe someone had discovered a rocky planet, but its orbit was too close to its parent star to make it suitable for life (based on what we know).

  10. Wow. That is so, so cool!

  11. Todd W.

    @The BA

    Phil, just wanted to point out really quick that you mention first that the age of the cluster is unknown, and then later that it is 5 million years.

  12. Given the various eccentric planets that we’re finding out there and evidence for “planet-planet scattering” in at least one system, ejected planets seem quite plausible.

    If it hasn’t been thrown out of the system (or has been perturbed onto some wide, wildly-eccentric orbit), the question is how to form a planet at that kind of distance – which raises the planets vs. sub-brown dwarfs question.

    Problem with finding planets the traditional radial-velocity way in this kind of system is that sunspots on young stars can mimic the RV signature of a planet – the supposed planet orbiting the young star TW Hydrae has been challenged on this basis. If this is an ejected planet, finding the culprit is going to be very tricky.

  13. Thanks for the explanation! If it is confirmed that this is a planet (and not a star or something else) we’re again one step closer to finding earthlike planets.

  14. LookingUpInReston

    Considering the reported distance (550 AU), a planet that size can’t form that far out that fast, and that it is my understanding that a three body interaction tends to eject the lightest object (yet no other object was found), my gut feeling is that this is a visual fluke. Still worth watching though.

  15. DG

    @John – ejection is possible, but extrapolating the migration mechanism that far out I think would also require coming up with one hell of an ejection event, like an encounter with another cluster star. This thing is WAY out there. And what are the odds that an ejection like this could lead to a stable orbit?

    But that’s the great thing about Astronomy – in a year or two, we’ll know!

  16. I had to sit on this news all weekend! Got the press release to edit late Friday (I do some work with the Geminifolk)… couldn’t wait to post the story today! And yes, they are being very careful with their work. It will take a year or more to confirm the orbit, etc… but it looks very, very promising.

  17. tacitus

    It’s only a matter of time before we image extrasolar planets like Earth. Think about it. It is probably going to be at least several decades (and quite possibly a couple of centuries) before we can travel between the stars — if we ever do — but ginormous space telescopes? Those we already know how to do in principle, and once orbital and then interplanetary flights are routine, we will begin to deploy them.

    One day, before this century is over, we will have a catalog of tens of thousands of images of planets, and probably many times more than that. This is just the beginning.

  18. Robbie

    I hate to admit this, but I have become jaded by planet discoveries. They haven’t surprised me for several years now. It’s still cool, but not anything I can get excited about anymore. Am i alone in this camp?

  19. @Robbie: I don’t know, but from a personal perspective, we are in different camps.

    Could you please send some marshmallows? We forgot ours for s’mores.

  20. Christopher Ferro

    What purpose do the 1 inch scale and North and East arrows have? Is it something useful to astronomers? It seems confusing from a layperson’s perspective.

    CJSF

  21. John Baxter

    Planet! News in 2010!

    This is very interesting. Confirmation will make it exciting.

  22. DG

    @ Robbie – yeah, I suppose the popular media/surface level of exposition could get old after a while. Discovering planets in multiple systems, slowly beating down the lower mass limit, slowly increasing the period limit – these things aren’t that exciting when written about over and over again in news articles.

    But the work that goes into these advances is actually increadibly impressive, and extremely difficult to do. And very smart people are coming up with great new ways to beat the odds all the time. This is really where some of the most exciting work in astrophysics is going on right now.

  23. Celtic_Evolution

    Phil -

    Nice post! I have one question, though… you make the statement:

    “If the object moves against the background stars along with the brighter star, then it must be physically associated with the star, and therefore it’s a planet. ”

    However, is it not true that if this were in fact a Binary system, and the second object is in fact a star, that these two would be similarly associated, from an observational standpoint?
    I have to admit, as exciting as the prospect of this being a visually confirmed planet around a sun-like star, given the distance between the two objects, the size of the smaller object, and the spectra measurements, at first glance it looks an awful lot like so many of the binary systems I’ve seen pictures of… even in the IR…

    This may be a totally stupid question, but what makes this so much less likely to be a fairly common binary system?

  24. John

    @Christopher: The scale is actually an angular size: 1″ is one arcsecond, which is an angle on the sky (there are 360 degrees, each degree is 60 arcminutes, each arcminute is 60 arcseconds), so that shows that the supposed planet is about 2 arcseconds from the center of the star on the image. If the distance to the star is known, we can translate that angular distance to an actual distance between the planet and star.

  25. Andrew

    I saw that picture and my heart jumped up through my throat. Then I read the spectral garbage and you TOTALLY KILLED MY SCIENCE HIGH PHIL >.>

  26. Christopher Ferro

    @John – d’oh! I never thought of ” meaning arcseconds, and it should have been obvious! Thanks… So, N and E is based on celestial coordinates, with the E flipped because of the telescope’s mirror?

    CJSF

  27. David

    Given the extreme distance between the object and the attributed parent star, then it’s orbit must be huge, perhaps measured in years… it would therefore be reasonable to assume that its relative arc position from our view (perspective) would remain very much the same for several days, if not weeks.
    I take it there are, as yet, no secondary views?

    I’m finding it hard not to agree with others regarding the notion of it being a cooler Binary.

  28. Sarah

    Couldn’t its orbit have been perturbed by a close encounter with another star? I mean, it’s still in a cluster.

    Although if this one was pushed out that far, then that probably doesn’t leave much hope for smaller things closer in.

  29. Well met, Dr. Plait. Well met.

    My friend is a student of Dr. Van Kerkwijk (one of the principal scientists involved) at the University of Toronto, and she told me about this a few days ago, but said for me to wait until the official press release (as opposed to the “I’m-excited-so-I’ll-tell-my-students-release”).

    In short, I was hoping to scoop you.

    You’re just too damn fast.

  30. There’s one thing we know for sure then: it’s not Krypton.

  31. I hoped to scoop Phil first, and had written my entry yesterday. I set it for publication at 10 a.m. EDT today…

    anyway… this is big news, but as everyb0dy is pointing out, more observations will be needed to nail this one… but, I gotta say, the preliminary results look very very good!

  32. Lao Tzu

    Well, the way I see it, since there is no way to find out whether the object has cleared the neighbourhood around its orbit, this can never be confirmed as a planet true to the IAU’s definition.

    Sorry folks…

  33. hmm… I’m not sure about my interpretation, but from the explanation of light coming from the thing, if it were a star it would be too old to be in that particular cluster, and if it’s young enough to be in the cluster, it isn’t massive enough to be a binary star…?

    also, i have a question: if I remember correctly, the other photographed planet was also very far from its sun. Would it be at all possible to photograph planets that would be closer in, or would they blend in with the radiation from their sun?

  34. BTW it should be 1RXS (stands for 1st Rosat X-ray Survey) not 1RSX.

  35. Lao Tzu, maybe not right away, but I think that in a very short time, we should be able to spectroscopically determine the extent and tau of the dust cloud (if any) and possibly be able to tell if there is a clearing going on…

    No need to be absolutist about it… and the nature of science is that it embraces change and further study… ;)

  36. So glad I found this site via Twitter.

    Very interesting article.

    Yes, it does seem a bit odd that such a massive planet, if it is that, should form so far out from its sun.

  37. Joe

    I have a question because I’m dumb.

    Why are all the exoplanets we find so crazy ginormous? I know we can’t yet see non-gas giants–yet– so is it just because so far we can’t really see anything on the scale of a Jupiter-sized planet, or is our solar system just super wimpy?

    Bonus question: at what volume/density does a planet start fusing hydrogen at its core?

  38. llewelly

    That’s 11 times the distance Neptune is from the Sun. And that’s a lower limit; it might be farther. That makes me very suspicious: we don’t know of any way to form planets that far from their parent stars.

    I’m thinking it had a naughty interaction with another planet eons ago, when it was much closer its sun, and was expelled for bad behavior.

  39. nitpicking, but precision IS Scientific:
    This would be the second planet ever seen directly in an image,

    Please insert “exosolar” between second and planet….

    ;)

    J/P=?

  40. Manveet

    I have a question because I’m dumb.

    Why are all the exoplanets we find so crazy ginormous? I know we can’t yet see non-gas giants–yet– so is it just because so far we can’t really see anything on the scale of a Jupiter-sized planet, or is our solar system just super wimpy?

    Bonus question: at what volume/density does a planet start fusing hydrogen at its core?

    Probably because our technology is still too feeble.

    It’s easier to see the effects of much larger bodies.

  41. Manveet

    I have a question because I’m dumb.

    Why are all the exoplanets we find so crazy ginormous? I know we can’t yet see non-gas giants–yet– so is it just because so far we can’t really see anything on the scale of a Jupiter-sized planet, or is our solar system just super wimpy?

    Bonus question: at what volume/density does a planet start fusing hydrogen at its core?

    Probably because our technology is still too feeble.

    It’s easier to see the effects of much larger bodies.

  42. Gary Ansorge

    50 billion km? Hey, that’s obviously a large solar collector that happens to be pointed in our direction. Proof that we are not alone,,,

    John: That’s “orbiting a sun like star”. Which, I think, IMPLIES extrasolar.

    GAry 7

  43. Davidlpf

    manveet it is not volume denisty but mass and fusion of hydrogen in the core begins at 75 to 80 jupiter masses, then it is considered a star. From 13 to 75 jupiter masses they are considered brown dwarfs. Brown dwarfs fuse deuteruim at 13 masses, and lithuim at 65 solar masses.
    Most exoplanets that are find are found by gravitional tugs back and forth on the star and to do this the must have alot of mass to do so.
    (find the details at wikipedia but no link I do not want to go into moderation, it’s scarry in there :-) .)

  44. Torbjörn Larsson, OM

    Exciting! And a (tentative) yay one or two years in advance…

    Well, the way I see it, since there is no way to find out whether the object has cleared the neighbourhood around its orbit, this can never be confirmed as a planet true to the IAU’s definition.

    Honestly, who cares about this being a planet or not, what would that tell us as regards a mature system? (Well, some perhaps, I’m a layman here, but it seems rather meager pickings.)

    What we dearly want to know is whether it is an exoplanet or not, isn’t it? And if it is, how it came to be in the neighborhood it occupies!

  45. Huron

    The University of Toronto strikes again!

  46. amphiox

    My question is does this object have to be in a stable orbit? Given how young the system is, could this planet be in an unstable orbit but just hasn’t had time yet to get ejected completely?

  47. amphiox

    Another question: is there a universally accepted definition yet to distinguish very large super-jovian planets from very small brown dwarfs? Is there a cut-off point based on pure mass (such as 13X Jupiters for deuterium fusion) or is the history of how the object formed, that is condensing from gas cloud like a star = brown dwarf and accreting in a protoplanetary disc around a star = planet.

    If the first, then what happens if the object in question gains or loses mass some time in its life (say a 12X Jupiter and a 2X Jupiter collide and merge), or a 13.5X Jupiter brown dwarf gets 1 jupiter mass worth of atmosphere stripped by a black hole? Does its designation then change?

    If the second, how would we tell the history of a borderline object? And could a >13X Jupiter object accrete out of a particularly big protoplanetary disc, or a very small object (say Neptune sized) collapse out of a very puny gas cloud?

    What about a large planet ejected into interstellar space. If we observed it later, what would we call it, and would we be able to tell? (Does it have to be currently in orbit around a star to be called a planet?)

    Is it possible for an object to be very close to the threshold, saw just below, but still be able to fuse deuterium due to some anomalous composition in its core? Or the reverse, an object just above the threshold but not fusing deuterium because of some unusual composition? Would such an object be considered a planet or a brown dwarf.

    It is interesting to me that these ambiguities exist at the upper end of the mass spectrum for planets, given the brouhaha regarding the lower end of the mass spectrum vis-a-vis Pluto, Eris, Ceres and company.

  48. ampiox, I think there was a blog post waaaay back during the “is pluto a planet?” debates about exactly this… with the conclusion being: all cut-off points for what is a planet and what isn’t are completely arbitrary

    though both mass and how it was created were mentioned for possible ways of deciding what is a super-jupiter and what is a brown dwarf.

  49. Todd W.

    I know why it’s so far out. Clearly, it dared to question evolution and champion ID, so it was Expelled.

  50. Davidlpf:

    find the details at wikipedia but no link I do not want to go into moderation, it’s scary in there.

    You can avoid that by providing a link via your name; just copy and paste the URL into the “Website” box — like I have just done. :-)

  51. oh like this just keeping a promise to some one.

  52. Steve

    Manveet,

    Dumb people do not ask relevant, focused questions like yours. I’d be willing to bet that 99 out of every 100 Americans could not even formulate these ideas, let alone express them.

    You’re not dumb, you’re just not an astrophysicist (yet).

  53. What about GQ Lup b and AB Pic b? Those probable planets also orbit K-stars and were imaged already in 2005?

  54. Mike Jackson

    “Click to embiggen”? Embiggen? Is it April 1 in some time zone?

  55. What about GQ Lup b and AB Pic b? Those probable planets also orbit K-stars and were imaged already in 2005?

    Both of these objects (especially GQ Lup b) are likely to exceed the deuterium-burning threshold of 13 Jupiter masses, so under certain definitions would be brown dwarfs.

    As for whether this is a useful limit for the planet/brown dwarf dividing line, some simulations of planet formation by accretion predict the formation of objects up to about 20 Jupiter masses, sometimes with large cores of heavy elements. Apparently fusion of deuterium could proceed in the layer immediately above the core in such objects. If this situation is realised in reality (and some systems e.g. HD 168443, HD 202206 indicate that it might) then the dividing line between planets and brown dwarfs becomes very tricky to define.

  56. Chanda

    You know, you hit the nail on the head. You said, “Go out there and look at the stars.” Um, I can count on ONE hand how many stars I can see from my back yard. And some of them are planets. HOW can people fall in love with science (astronomy in particular) if there are NO blasted stars to look at. This is a real problem. I’m not just whining. Our babysitter has no idea what she is missing. My kids, have a clue, because whenever we travel out of the light pollution that is better known as Houston, I make a point of looking up. And if there is an “event” I try to travel to the boonies to see it. But I’m guessing most parents don’t do that.

    How How HOW can they fall in love with something that isn’t? Almost everyone lives in or near cities.

    Right now, Houston is powerless for the most part. And still no stars. Clouds, a full moon, but no stars. Bah. Yes, *I’m* trying to leave this place but no matter what, most people will be starless. At least for the foreseeable future.

  57. Dunc

    (1) is a bummer, and is unlikely just due to statistics; it’s isn’t high odds to see an object like this by coincidence so near another star.

    For an individual star, sure – but haven’t we looked at quite a lot of stars for this sort of thing so far? Keep looking long enough, the odds improve…

  58. Gary Ansorge

    Manveet:

    Insecurity, the bane of our modern existence. The Dalai LAma once said of this intellectual self doubt, that Buddhists consider it a mental illness and would try to cure the anomaly. Forge ahead until you’re proven wrong, then accept correction with good grace. By making mistakes, we make progress. It’s the only way we can know what doesn’t work,,,

    GAry 7

  59. I don’t understand the problem with its distance from the star. Is not Sedna at a comparable distance in our solar system?

  60. Don Snow

    I go along with Celtic_Evolution and Dave, in wondering that this could be another star in a binary system.

  61. Quentin – the difference between Sedna and an 8-Jupiter-mass planet is quite substantial: the formation of gas giants is limited by how long the gas in the circumstellar disc stays around – which is on the order of 10 million years or so – gas giant formation therefore has to be fast. The problem with forming a gas giant is that under traditional models you need a massive core before the planet begins to accrete hydrogen – the threshold is likely somewhere around 10 Earth masses. Far away from the star, the orbital velocities are very slow, so the timescale to put together a 10 Earth mass core is very long – in fact, it is so long that the disc of gas and dust would have dissipated long before the planet could start accreting the hydrogen envelope.

    Basically, at the kind of distance for this object, you cannot form a gas giant in situ by accretion. Various kinds of gravitational instability might do the job, but this is getting uncomfortably close to how stars form. Alternatively it might have formed further in where the timescales are more favourable for building gas giants, then had an interaction with another massive planet which threw it out of the system.

  62. Gary Ansorge

    Looks to me like a failed brown dwarf, possibly one that began accreting gas and dust around the same time as the primary, but then had it’s fuel source dissipated when the primary lit up.

    Gary 7

  63. Gary Ansorge

    Should have pointed out, if there was just a few percent difference in the initial cloud density, one potential star could accrete mass faster than the other, leading to initial fusion earlier,,,

    gary 7

  64. @andy: I am aware about the problems of defining “planet”. I just wondered about that “first picture”-stuff. A K7 -star is not really “sun-like”. And they have not even confirmed the common proper motion of the star and the possible planet. Additionally the mass of this object could also be higher than the published 8 MJ (according to some colleagues who know about this stuff). So this discovery is in fact an unconfirmed possible planet around a K7 star – and GQ Lupi also is a possible planet around a K7 star. So if there is any “first picture” it should be that of GQ Lupi. (In fact, there exist 5 pictures of possible planets prior to this one)

  65. Jen

    I think I have visited this planet on Spore. ;-)

  66. Natovr

    Ok.. I don’t understand this, on the map there is “N and E” and the sign for 1 inch with a scale… i didn’t know that a star can be 1 inch, and that compasses work in space

  67. I’m young. I’m not even a postdoc.

    When I was little and reading my first kiddie books on astronomy, “are there planets around other stars?” was still an open question.

    Now we’re finding new ones every month.

    Awesome.

  68. Natovr: The symbol double-prime means arcseconds as well as inches. In this context it means arcseconds, so the scale bar tells you how much of the sky is covered by this image. (Answer: not much)

    As for the north and east bit, imagine the sky is a sphere (the “celestial sphere”) with all the stars drawn on the inside of it. When we stand on Earth, we look up towards the inside of the sphere. The north pole of the sphere is above the north pole of the Earth, and the equator of the sphere is above the Earth’s equator. Latitude on the celestial sphere is termed “declination”, and like latitude, increasing the declination moves you towards the north pole. So the arrow labelled “N” points in the direction of increasing declination.

    Longitude on the celestial sphere is termed “right ascension”. Usually this is quoted in hours: 360 degrees is 24 hours. On the Earth, the east direction is the direction of increasing longitude, and likewise here the east direction is in the direction of increasing right ascension. This direction is marked by the “E” arrow. Now you might notice that the “E” arrow is pointing the opposite way to how it appears on maps… on a map, E is 90 degrees clockwise of N, but here it is 90 degrees anticlockwise. Is the image mirror-flipped? Answer is no… the reason is because we are looking at the celestial sphere from the inside, whereas on the Earth we look at it from the outside. This is why the arrow looks like it is pointing the wrong way.

    So these directions indicate how the image is orientated in Earth’s sky, not about where a compass would point if you took it to the 1RXS1609 system.

  69. Thats a great discovery. Congratulation for everyone who have done the observation and the math. Do someone have the cartesian ephemeris for this planetary system ?

  70. The Bad Astronomer asked :

    “Is this it? Is this the very first image of a planet orbiting a star like the Sun?”

    And then seems to have forgotten or discounted our little orange dwarf 1 RSX J160929.1-210524 and its exoplanet when noting Fomalhaut b for this honour!

    Click my name for the BA’s write up on Fomalhaut b and HR8799 b,c & d being imaged. Busy – and great – time for exoplanet imaging of late. :-D

    Congratulations to all those involved in this discovery. Awesome news if quickly surpassed by even better candidates, incl. now Beta Pictoris b. (?)

    Also a question :

    How like our Sun does a star have to be before counting as a Sun-like star? G type yellow dwarf only? G K & F class? Main-sequence (I’ve seen Altair, a
    fairly hot massive A-type star called “sunlike” which I’d dispute!) or what?

    BTW. BA please could we have a better archives system here? One that shows us more stories (or headlines therof?) so we can find items /posts threads /whatever y’callems more quickly rather than having to scroll through so so many older entries pages? Please?

    Surely I’m not the only who thinks ‘Oh wasn’t there a story about X a while ago?’ and tries to find it by checking back …?

  71. Tally of exoplanets actually imaged or candidates for that now equals :

    1. Fomalhaut b 2008 Nov Nearby bright star

    2. Beta Pictoris b 2008 Nov. Nearby brightish star

    3. HR 8799 b,c & d Nov.2008 Distant Procyonese (?)(1.5 mass Solar) star withprotoplanetary disk containg planets at 25,40 & 70 AU.

    4. 1 RSX J160929.1-210524 K7 orange dwarf Sept 15th 8x Mass Jove 11 x Neptune’s distance (or 330 AU?)

    5.2M 1207b or in full 2 MASSW J1207334-393254 imaged April 27th 2004 around a brown dwarf, a 5 Jupiter-mass exoplanet or perhaps brown dwarf this planet orbits 55 AU from its brown dwarf sun.

    6.GQ Lupi b 2004ish (?) Probable brown dwarf 1-42 mJ @100 AU

    7. AB Pictoris b 2003 March (earliest but probable brown dwarf) 250 AU out.

    Pretty impressive & amazing. :-) 8)

    Well it is to me at least, I love hearingabout exoplanets and frankly I don’t know why more isn’t made of such discoveries of entirely new planets around other stars by the media and wider community.

    BTW. Speaking personally, my preference would be for limiting the term ‘sun-like’ to main-sequnce dwarf stars of classes G, F and K.

  72. StevoR:

    And then [Dr. Phil Plait] seems to have forgotten or discounted our little orange dwarf 1 RSX J160929.1-210524 and its exoplanet when noting Fomalhaut b for this honour!

    Err… StevoR, Dr. Phil Plait has not “forgotten or discounted” the K7 dwarf star 1RSX J160929.1-210524 and its exoplanet. It is because the exoplanet — more likely a Brown Dwarf — around aforementioned star hasn’t been confirmed yet, as he mentioned to someone else who raised the point in his recent post (click on my name for the link), that is the reason why he stated that Fomalhaut b is the first confirmed exoplanet.

  73. ADDENDUM:

    That last line should read: Fomalhaut b is the first optically confirmed exoplanet.

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