Another direct picture of a planet orbiting an alien star confirmed!

By Phil Plait | June 30, 2010 10:39 am

Astronomers have confirmed that an object in an image from 2008 — thought at the time to possibly be a direct image of a planet orbiting another star — is in fact a planet.

I’ll explain in a sec, but I want people to understand that this discovery is being touted as the first direct image of a planet around another star. It isn’t. Nor is it the first direct image of a planet orbiting a sun-like star. What this is is the first direct image of a planet orbiting a sun-like star taken using a ground-based telescope. While that may sound overly picky, it’s actually a significant achievement, and worth noting.

First, the planet picture:

This image, taken in 2008 by the Gemini North telescope in Hawaii, shows the star 1RXS J160929.1-210524 (I’ll call it 1RXS 1609) in the center, and the planet (1RXS 1609b) indicated by the red circle. As I wrote about this in 2008:

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 problem was, it might have been a background galaxy or another, fainter star. It’s happened before; I spent weeks working on a similar image from Hubble that turned out to be a background star (grrr). However, new images revealed the object is in fact orbiting the star, and is a planet. Here’s the proof:

gemini_1rxsb_bound

On this plot, the separation of the star and object are shown on the y-axis, and time on the x. The star is very slowly moving across the sky as it orbits the center of our galaxy. If the object were a background star, moving at a different rate, the separation between it and the star would fall on or near the purple line, changing as they move separately. If the object were a planet, the separation wouldn’t change much at all as they traveled together across the sky. The observations of the object are shown as black dots, and fall pretty much right on the line marking it as a planet.

Cool!

Given these observations, and the distance of the star of about 500 light years, we know the planet 1RXS 1609b has about 8 times the mass of Jupiter, orbits the star 45 billion km (27 billion miles) from its star — 300 times the Earth-Sun distance — and has a temperature of 1500 C (2700° F). The star is a bit less massive than the Sun, and isn’t nearly hot enough to heat the planet to that temperature. The reason the planet is hot is because it’s young, only 5 million years old. It’s still cooling off from being formed, and in a few billion years will be very cold. But right now it’s warm enough to glow and be detected by us.

This discovery is a technological achievement because the star and planet are very close together in the sky, and difficult to separate. From the ground, the Earth’s atmosphere blurs the images and scatters the star’s light, making the planet extremely hard to see at all. Even more amazing is that they could get an actual spectrum of the planet and use that to determine its temperature; that’s even harder to do (like juggling is hard, but doing it on a unicycle even harder). So all in all, a truly remarkable event.

However, as I pointed out, it’s not being reported completely accurately.

First, it’s not the first exoplanet even seen directly. That distinction belongs to the planet 2M1207b, which orbits a brown dwarf about 230 light years away. Brown dwarfs are smaller and cooler than the Sun, and are not fusing hydrogen into helium in their cores, so some people don’t consider them to be real stars. So while the object seen is a planet, it’s not orbiting a sun-like star.

OK, but a planet already has been directly imaged orbiting the star Fomalhaut. That star is hotter and more massive than the Sun, but is far more sun-like than a brown dwarf. The first image of the planet Fomalhaut b was taken in 2004 using Hubble Space Telescope, and the second confirming image in 2006. It took two more years to make sure everything was correct, and the news announced in 2008. So while this was announced after the image of 1RXS 1609b was first taken in 2008, the first image of Fomalhaut b was taken in 2004, four years earlier.

So some people are saying this observation of 1RXS 1609b is the first direct image of a planet orbiting a sun-like star taken by a telescope on Earth (Hubble is orbiting in space). I’ll grant that. And while that may seem a bit nit picky, it’s actually pretty cool. Observing exoplanets from space is in some ways easier than from the ground, because there’s no air to screw up the image. It’s still incredibly hard, but easier. From the ground, though, there are techniques that improve the odds a lot. Still, these are very difficult observations and are a fantastic achievement.

I’ve seen this reported with inaccurate headlines all over the place, so please be aware that there are misleading and even exaggerated reports about this. But also keep in mind that despite the breathless hyperbole, this really is pretty cool news.

Comments (69)

  1. Aw, it’s cute. Can we name it Bob?

  2. Cool. So, how long is it’s orbit, and when can we expect a “movie” from a series of images, showing it in orbit?

  3. Messier Tidy Upper

    Awesome news. Even if we do have to be a bit picky. Congratulations to the team involved! :-)

    So some people are saying this observation of 1RXS 1609b is the first direct image of a planet orbiting a sun-like star taken by a telescope on Earth (Hubble is orbiting in space). I’ll grant that. And while that may seem a bit nit picky, it’s actually pretty cool.

    Very cool really – which is ironic because we only discovered this planet because it is still so hot! ;-)

    @2. Ken B Says:

    Cool. So, how long is it’s orbit, and when can we expect a “movie” from a series of images, showing it in orbit?

    Given its 300 Astronomical Units from its less massive than ours Sun and that Pluto in an orbit which ranges from roughly 30 to 50 AU takes nearly 250 years to circle our more massive than theirs star – then I’d say, a *ve-ery* loo-ooong time indeed. ;-)

  4. Chris

    @Ken #2 Pluto is 40 AU from the sun (semi major axis) and it takes ~250 yrs to go around. Remember Kepler’s third law, then the period would be 300^(3/2) yrs or ~5200 years. Of course we don’t know how elliptical the orbit is, the inclination to us, where in its orbit it is, so I could be way off. It is also a little longer since the star is a less massive K star (our sun is a G type). So I would anticipate decades before we could get a movie.

  5. dre

    Is the up-and-down movement of the planet around the bound on the plot actually showing the orbital motion of the planet, or is that just sort of a random measurement error? MTU may have answered this with comment 3 already…

    And better yet, is the waviness of the background movement on the plot an effect of our orbital motion?

  6. Matt T

    How lucky we are to live in this time: the first moment in human history when we are, in fact, visiting other worlds
    Dr Carl Sagan

    (Just change “visiting” to “seeing”. And shift the meaning of “other worlds” a bit.)

  7. Craig

    Phil, I got the distinct impression that your nose was just a bit out of joint about this. I think you spend a little too much time defending your Hubble, and that overshadowed the achievement a bit.

    Typically your posts would be bubbling over with enthusiasm about such an amazing photo, but this one is equal parts astrophilia and petulance.

    I’ll say it for you:

    Holy haleakala!

  8. Gary Ansorge

    Brown dwarfs don’t fuse hydrogen? At ALL? SO, I guess the general supposition is that they’re merely glowing from mass contraction?
    It seems to me that mere random kinetic impacts would cause SOME fusion to occur, even in a planet as small as Jupiter.

    Great pic.

    Gary 7

  9. Messier Tidy Upper

    @ Chris :

    It is also a little longer since the star is a less massive K star (our sun is a G type).

    Yes indeed – our star is a G2 V yellow dwarf towards the (relatively) hotter, brighter, shorter-lived end of spectral class G.

    (V = Main sequence or dwarf star fusing hydrogen at its core – 90 % of all stars are in this category. Exceptions are supergants (= I) , giants (= II & III), subgiants (= IV) and white dwarfs (= VII) which fuse different elements – or nothing – at their cores. Plus the “metal” poor sub-dwarf class! (= VI)

    1RXS 1609 is a K7 V orange dwarf star dimmer and fainter than Alpha Centauri B (K1) & Epsilon Eridani (K2) as well. Its almost but not quite a red dwarf at the (relatively) cooler, fainter, longer lived end of spectral class K.

    On the old thread (#86.) I [posting then as StevoR] wrote :

    ***

    The count of Directly imaged Exoplanets or candidates for that now equals :

    1. Fomalhaut b (in 2008 Nov) Nearby Sirian (A3 V) star – the second brightest star with a known exoplanet orbiting it and 18th brightest star inEarth’s skies. (Pollux an orange giant holds that particular record but only just being the 17th brightest in Earth’s night skies.)

    2. Beta Pictoris b 2008 Nov. Another nearby brightish Sirian (A3-A5 V) star which was one of the first to have a protoplanetary disk discovered along with Fomalhaut and Vega.

    3. HR 8799 b,c & d Nov.2008 Distant Sirian (A5 V) star 1.5 mass solar with a protoplanetary disk containing three planets at 25, 40 & 70 AU.

    4. 1 RSX J160929.1-210524 b (K7 V) orange dwarf Sept 15th 2008 observed first, 8x Mass Jove at about 300 AU distance. Confirmed June 2010.

    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 orbiting @ 100 AU from its sun which is *not* a fully formed star but rather a still forming protostar.

    7. AB Pictoris b 2003 March (earliest detection but probable brown dwarf) 250 AU out from a 30 million year old (K2 V) orange dwarf.

    There have been a few other candidates that turned out to be false alarms but I think that’s the current list as best I’m aware. Please let me know if I’ve missed any! ;-)

    Pretty impressive & amazing.

    Well it is to me at least, I love hearing about 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 star’ to main-sequence dwarf stars of classes G, F and K. :-)

    ***

    Which I think bears repeating here (please forgive me if not!) and has now been updated as you can see. :-)

  10. Messier Tidy Upper

    @8. Gary Ansorge Says:

    Brown dwarfs don’t fuse hydrogen? At ALL? SO, I guess the general supposition is that they’re merely glowing from mass contraction?
    It seems to me that mere random kinetic impacts would cause SOME fusion to occur, even in a planet as small as Jupiter.

    Brwon dwarfs – classed as spectral classes L & T do fuse deuterium which is a “heavy” form of hydrogen but that’s not usually considered to be quite the same thing.

    They also do shine from their internal heat of contraction & (I think?) formation – especially at infra-red and radio wavelengths does Jupiter and, I think (?), our solar systems other gas giants as well – with the possible exception of the oddly cold “sideways planet” Ouranos.

    Curiously enough,in actual colour brown dwarfs are probably magenta (pinkish purple) as the BA noted on an earlier post on these low mass “really successful Jupiters” or “failed stars” as others call them. ;-)

    PS. Wikipedia -and James Kaler’s superluminous (superlative = ‘beyond just brilliant’ ) Stars website among others can be your friend here & quite informative too natch! ;-)

  11. Don Sakers

    Is anyone working on coming up with names for all these exoplanets we’re finding? The IAU, maybe? What are the rules? Do we have to have a direct visual image before an object is granted a name? Does there have to be a vocal fan club for the object? Tell us, Phil.

  12. Messier Tidy Upper

    Weirdly enough too, HR 8799 one of the first stars to have an exoplanet directly imaged around it is located very near in the sky to the first exoplanet ever discovered around a main-sequence sun-like star – 51 Pegasi.

    They are on either side of the “horse’s head” end of the Great Square of Pegasus asterism on the line between Markab (Alpha Pegasi) and Scheat (Beta Pegasi) and are practically next to each other as seen in Earthly skies in one of the wonderful if meaningless astronomical co-incidences that pop up from time to time. :-)

    Both can be viewed with the unaided human eye given dark enough skies as they are fifth (51 Peg) and sixth (HR 8799 or Gadolabove*) magnitude respectively. :-)

    See : http://stars.astro.illinois.edu/sow/hr8799.html

    & for more on brown dwarfs (sorry about the “brwon” typo in post # 10 above) see : http://en.wikipedia.org/wiki/Brown_dwarfs

    – incl. a possible new spectral class Y for still cooler examples.

    Or for an illustrated view or for comparison two of a boarderline brown dwarf /red dwarf and planet system see :

    http://www.nd.edu/~bennett/moa07blg192/

    Which is linked from the BA’s “Welcome to our tiny family” post of Juen 2nd 2008 discussing the low mass dwarf sun MOA-2007-BLG-192L and its 3 x Earth-mass planetary companion.

    * “Gadolabove” being my proposed name for it taken from its three stellar claims to fame, these being it is simultaneously :

    – a Gamma Doradus variable – a class of subtle variable stars.

    – a Lambda Bootis “metal poor star & also having

    – a Vega style protoplanetary disk. Apparently HR 8799 is the only star known to belong in all three categories! :-)

  13. andy

    The mass ratio of the 2M1207 system, plus the wide separation and the fact that each object appears to have an independent disc orbiting it (the disc of the primary gets nowhere near the location of the secondary), suggests that the system is more akin to a binary star than a star+planet combination. That would make 2M1207b a brown dwarf, albeit one that is not massive enough to fuse even deuterium.

    As for 1RXS1609b, the interpretation is definitely not clear. It could be a scattered giant planet (which implies there should probably be an even more massive planet closer in to the star which did the scattering), or it might be another low mass brown dwarf. At least with HR 8799, Fomalhaut and Beta Pictoris there are circumstellar dust belts interior to and beyond the orbits of the planets, which imply that like true planets their companions formed out of the disc rather than by direct collapse.

    Incidentally the second planet of Upsilon Andromedae is above the deuterium fusion limit: as has been predicted by theoretical models, planets can be formed which are massive enough to undergo deuterium fusion in their interiors. Deuterium fusion as a planethood criterion leads to confusing interpretations of observed systems. The universe seems perfectly capable of forming non-fusing stars and fusing planets.

  14. Your post about the same picture in 2008 was talking about it being “the very first image of a planet orbiting a star like the Sun,” so is there a disconnect that I’m not noticing?

    On another note, I just ordered Death From the Skies! a few minutes ago and am looking quite forward to reading it this weekend. :D

  15. Daffy

    I wonder if there will ever be a way to see if the extra-solar planets follow Bode’s Law at all?

  16. RAF

    Re. Daffy’s post concerning bodes “law”…

    To answer that question, yes, I’m sure that we will eventually locate a Solar System similar to our own that roughly corresponds to “bodes law”, however it makes little difference one way or the other because “Bodes law” is numerological nonsense and is in no way a predictor of planetary orbits.

    It’s called coincidence and it happens in the real world all the time…there is no significance to it at all.

  17. Allen

    @Don Sakers 12:

    I don’t think so. We’ve discovered over 400 exoplanets. Way too many to name. Most of the stars we’ve ever observed don’t even have names, even in constellations that the ancient Greek have observed and knew about.

    Still, this is a very cool discovery, and a pretty cool step forward for ground-based observatories.

  18. “inaccurate headlines all over the place, so please be aware that there are misleading and even exaggerated reports about this”

    :o Really?! The media would do such a thing!? I am shocked, amazed, and dismayed. I mean, they are usually so neutral, factual, and even knowledgable on what they report!

  19. XPT

    I’m in awe about all the new discoveries in the extrasolar planets field. So promising!

  20. Blooper

    Does anyone here know if that is a true color (as we would see it with the naked eye) image of 1609b? Or is there no way to ascertain the true color of the planet?

  21. Peter Hornby

    Touch of confusion here. According to the image, the angular separation is about 2″-3″, which seems roughly correct, given the distance of the system and how far the two objects are apart. So, it’s not the separation itself that makes this detection difficult – I can resolve 2″ double stars with my backyard telescope with no trouble – or not much. The issue, it seems to me, is that the planet is so amazingly faint. I don’t know what B’s apparent magnitude is, but if you make reasonable assumptions about how intrinsically luminous it might be, it’s hard to see how, from 500 light years away, it could appear much brighter than magnitude 30.

    This is truly an amazing achievement, and it’s only the start.

  22. Daffy

    RAF, that is exactly why I am curious. If they find the same pattern around another star, it would make it more than coincidence, I should think. Something caused it…for reasons I can’t explain, it has always fascinated me. The question is, is it unique?

  23. GK4

    Here are some ideas for names that can be used for either the star 1RXS J160929.1-210524 or the planet. They are derived from a few of the stellar designations listed in Simbad:

    Upziatl
    Arkoasosa
    Maoyayadex

    … and I have more options, and variations depending on what rules work best.

    What do you think of names like these? Too strange? Better than numbers? I’m working on a system for making names, and would appreciate feedback.

  24. olderwithmoreinsurance

    Hard to see how this object can be a “planet” in the sense we’re all used to. As Andy said above, it’s WAY to far out to have formed from a disc around its K7 parent star. It might be scattered, but that would imply other giant planet(s) and a disc (has a disc been seen in the IR?). More than likely it’s a brown dwarf (with no orbital info all mass estimates are model and age dependent and are quite uncertain). It could well be a brown dwarf with a common proper motion to its “primary”. And I certainly wouldn’t call a K7V star “sun-like”: it’s mass should be about 0.5x that of the sun and it’s radius roughly 0.6X that of the sun (there’s at least one detached k7 eclipsing binary known.).

  25. Messier Tidy Upper

    @24. GK4 Says:

    Here are some ideas for names that can be used for either the star 1RXS J160929.1-210524 or the planet. They are derived from a few of the stellar designations listed in Simbad:

    Upziatl
    Arkoasosa
    Maoyayadex

    … and I have more options, and variations depending on what rules work best. What do you think of names like these? Too strange? Better than numbers? I’m working on a system for making names, and would appreciate feedback.

    Well I for one certainly prefer them to numbers! I do find them strange although strange could be good.

    I like the idea of naming exoplanets properly – I think its one reason why they haven’t got as much interest from the general public.

    Lacking real “names” as opposed to catalogue designations is a real problem methinks.

    Its hard to pronounce, memorise and talk about a string of numbers as a real place.

    To relate to and come up with adjectives for an numeric-alpha-soup.

    Take this world – an amazing boiling hot superjovian globe that is a real place we’ve now photographed!

    Even the BA has shortened 1RSX J160929.1-210524 (TOO MANY NUMBERS! TOO LONG to talk about easily even on a [mainly] science blog) to just “I’ll call it 1RXS 1609″ – now that’s a step in the right direction but it’s still not an actual name.

    Why not? Well, how is it pronounced – is it One R ecks S one thousand six hundred and nine? One R Excess one six oh nine? Won are excess sixteen oh-nine (like the year!) Or something else?? How can we tell?

    Imagine setting a story on or discussing it in a paper or essay “Karina flew in the vivid still hot uppermost reaches of 1RXS 1609ean skies looking through the wisps at haze at the star-filled black above and the vivid lower clouds decks below?”

    Or the “1RXS1609ite atmosphere consists of cloud layers of X chemicals mostly Y and Z at temperature of _____ degrees.” Etc.

    There is a language problem here. A problem which effects how we communicate about and relate to these new found worlds of other suns.

    It does need addressing I think. How do we do that?

    ****

    End Part I

    (Comment broken into parts for length hope this approach is okay, I know sometimes long posts are seen as bad. What do folks think of this idea?)

  26. Your Name Here

    What I would see as picky is the first direct image of a planet orbiting a sun-like star taken from a ground-based refracting 30-inch telescope owned by an amateur who lives in China who bought it from a company which has just gone bankrupt.

    But that would be overkill.

  27. Messier Tidy Upper

    Part II – continuing from #26:

    *****

    So how do we solve the need for exoplanets to be named?

    Some suggestions and examples –

    1a. Mythological names : Eg. 51 Pegasi b (the first Hot Jupiter ever found) has been unofficially named ‘Bellopheron’ from the greek mythology of the flying horse legend where Bellopheron was the hero who rode Pegasus. Likewise, HD 209458 b the first transisting Hot Jove is frequently dubbed “Osiris” after a dismembered Egyptian God.

    This works well and follows from traditional mythology and astronomical practice. It’s good to relate and connect with and acts as a Mmnemonic (memory aid), the names are poetic and evocative and have character.

    Problem here is the supply of mythical names will eventually run out and has been mostly used up in our own solar system naming planets of all varieties from gas giants, rock dwarfs & ice dwarfs to moons, moonlets and asteroids.

    We can, of course, and now often *are* using mythologies outside the Greco-Roman pantheon, names derived from indigenous cultures and non-Western cosmogonies such as Sedna (Inuit sea goddess), Haumea (Hawaaiian fertility goddess) and Varuna (Hindu goddess) for some of the new worlds being discovered in the far reaches of our solar system around and beyond Pluto.

    (There’s a whole others issue over what to call this region but that’s another topic! Must .. try .. and .. stay .. on ..topic!)

    One way around the “too many objects not enough names” problem would be accepting some duplication especially when confusion is unlikely. For instance, we already have one of Pluto’s 3 moons being named Hydra – which is duplicating the name of a constellation and Nix which duplicates, albeit with a slightly different spelling, the name of an asteroid.

    Therefore why not use names twice provided there can’t be too much chance of the objects being confused? An exoplanet and a moonlet are very different things after all and it will be clear via context which is referred to about 90% of the time surely!

    1b modern mythologies Plus we needn’t limit ourselves to
    ancient mythologies either! For example Eris was first known as “Xena” an informal nickname that far beats (IMHON) 2005 UB313 its “official” tag for ease of conversational use. Similarly, Haumea was nicknamed “Santa” and Makemake was known by “Easterbunny.” Funny perhaps but also memorable and poetic-ish why not use these names as alternatives for exoplanet designations too? I don’t really see why not personally!

    Or in the field of exoplanets look at the informal naming – already suggested by other people of planets after similar ones in the Star Wars universe eg. OGLE-05-390 L b a low mass (5 x earth) freezing exoplanet discovered by microlensing around a distant red dwarf was unofficially named “Hoth” afetr the ice planet in SW – Ep. V : Empire Strieks Back and HD 188753 b discovered orbiting three stars has been called “Tatooine” after the famous Star Wars Desert planet. (NB. In reality HD 188753 b is a gas giant of Jovian mass [?] and its very existence has, I gather, been questioned by further studies.)

    2.Descriptive names : Another good idea and quite a simple yet effective one is to name notable exoplanets after the trait that make sthem so noteworthy -for instance HD 80606 b which has a very Comet-like, highly eccentric orbit could be called the Comet[orbit?] Planet and TrES-4 the largest and least dense exoplanet has been termed the “Balsawood planet.” Naturally an issue will arise if many planets are found with the same traits or even more extreme cases are found – it may be more suitable as a planet class name (“Roaster” was used occassionally for Hot Jupiters for ex.) than for individual worlds but again, its memorable and immediately indicates something significant about the planet in question.

    3. Alternative star & constellation names My personal favourite idea is to use old star names and alternative designations for the star or constellation. For instance Pollux b, the superjovian exoplanet orbiting the nearby orange giant has been unofficially dubbed “Polydeuces” after an alternate spelling of Pollux and if planets were found around Alpha Centauri (either A or B) they could be named after a number of different if very rarely used proper names that star has eg. Rigil Kentauros, Toliman and Bungula.

    Imagine, hypothetically, we find five rocky worlds orbiting Alpha Centauri, three around A and two around B. The one’s around B could be named Rigil and Kentauros, the ones around Alpha Cen A Toliman and Bungula and .. am I missing a name here? Not quite! One could be named New Earth or Terra Nova for obvious descriptive reasons! Lets hope so anyhow. ;-)

    This technique has the advantage of connecting the ancient and modern perspectives on stars and constellations – our past relationship and understandings and starlore associations with the new worlds discovered and revelaed intheir splendour by awesome acts of scientific work. Such alternative star names are memorable and interesting and have their own poetry and history and are, I think, highly appropriate.

    Again a “too many worlds, too few names” issue may arise especially for the larger constellations or those poor in mythology and human historical association. Still with sufficent research and ingenuity I think this method of exoplanet naming has a lot in its favour. :-)

    ***

    [End part II – Continues in part III.]

  28. andy

    Actually I don’t think most of the exoplanets that are known should be named at the current time, if only because we don’t actually know if most of them are in fact exoplanets rather than brown dwarfs or even low mass stars in nearly face-on orbits. Note the case of HD 33636, whose companion turned out to be an M-dwarf star rather than a ~10 Jupiter mass planet.

  29. Messier Tidy Upper

    Part III [Continuing]

    ***

    4. Discoverer’s Name or Choice : This is how we name comets and personalises these worlds as well as offering both incentive and variety. For instance if say planet hunter Debra Fischer (to use a real astronomer’s case) discovers an exoplanets then why not follow the Barnard’s Star, Van Maanen’s Star, Plaskett’s Star(s) tradition and rename it for her? After all if she found a comet it would be called Fischer’s comet* after her and if she discovers a minor planet(asteroid or ice dwarf) she gets to name it or at least suggest a name for it. Why the blazes not do the same here? Of course, even with sharing names around among exoplanet hunting team members that may lead to a lot of Marcy-1, Marcy -2, Fisher-1, Fischer-2, Fischer-3 etc .. designations but still – it beats just a number in theease of memorability and discussability (a real word? Now it is!) stakes methinks!

    (* Yes, I know there’s technically an IAU periodic comet designation used that most people generally don’t. Folks generally like names not numbers. Catalogue designations have their place I guess but names are better.)

    5. Other I’m not quite sure how (#24.) GK4 is deriving his names but that’s clearly a different alternative again & there are numerous other possibilities too such as “modifying” the acronymns into words by adding vowels or extra consonants for example turning the RSX in 1RSX J160929.1-210524 b into ‘Rassax’ or ‘Risux’ or ‘Resyx’ and so forth.

    Then there’s the possibility of thematic invention eg. we’ve had (still have?)the MOA survey which discovers a lot of low mass brown dwrafs and maybe, say, it finds some exoplanets. The first significant low mass could be called “the Moa star” or “Moa- world” (although the latter does sound like a shop selling lawnmowers! ;-) ) turning the astronomical survey acronymn into the eponymous extinct flightless bird. Then the next one it discovers could be Moa-two or, instead, we could make a theme of extinct or flightless birds Emu world, Ostrich world, Dodo world, etc .. Sounds a bit funny perhaps and not much connection with astronomy and starlore but these names are memorable and poetic and, after all, we already have as an example the Peacock Star in our sky. (Alpha Pavonis’ proper name in case you’re wondering.)

    To use another example any particularly notable brown dwarfs and possible planets discovered by the WISE telescope could possibly be named after famously wise individuals eg. Socrates, Einstein, Solomon, Phil Plait, etc… ;-)

    So there are lots of possibilities and no reason we can’t use a *mixture* of all these methods for naming as well for different individual exoplanets. :-)

    We have creativity, we have imagination, we have poetry – catalogue names lack all these elements and are, I think, a barrier to communicating and discussing these splendid newfound worlds of other stars.

    Of course, the IAU has a lot of say here, the most of anybody and maybe they’re currently working on this issue. However, if so I haven’t heard anything about it. :-(

    I’d love to see something- almost *anything* – happen in this matter because dull unweildly non-names like 1RSX J160929.1-210524 b are making things harder for astronmers and science communicators in my view. They are a real pet gripe of mine. (Oh you’ve noticed? ;-) )

    For pity’s sake, can we at least have no more than say 5 max – at the very most – numerals per designated object & preferably fewer!

    When talk about objects we use names not barcodes.

    When we talk about people we refer to them by name not by social security or other number – and doing otherwise is correctly seen as dehumanising them, robbing them of something important, if intangible.

    This is I think similar with exoplanets.

    Merely numerical designations seem dull, dry, dispassionate, unexciting, unevocative and unpleasant.

    Contrastingly names convey meaning, interest, evoke memories, histories, visions and personalities.

    Exoplanets are real places, they are magnificent spectacles that should fire our imaginations – they certainly do mine! I love these discoveries and that we can make them and I think they are worth naming properly! Giving them respectable, real names that can be used to capture people’s hearts and minds and make things exoplanet-wise more engaging and exciting and enjoyable for more people.

    What do you think BA?

    What do others here think?

    PS. Does this segmenting into parts approach work for folks. I know all these parts are still long-ish but, durnnit, this is something I really want to discuss in slightly more depth. I think it is related to the Opening Post and worth talking about here. I hope this is okay with y’all & my apologies if not. Thanks for your forbearance.

    – Messier Tidy Upper ex-StevoR here.

  30. Messier Tidy Upper

    @ 25. olderwithmoreinsurance Says:

    Hard to see how this object can be a “planet” in the sense we’re all used to. As Andy said above, it’s WAY to far out to have formed from a disc around its K7 parent star. It might be scattered, but that would imply other giant planet(s) and a disc (has a disc been seen in the IR?). More than likely it’s a brown dwarf (with no orbital info all mass estimates are model and age dependent and are quite uncertain). It could well be a brown dwarf with a common proper motion to its “primary”.

    Like the hypothetical “Nemesis” companion to our own Sun which has been imagined as an explaination for the apparent periodicity in mass extinctions?

    If our own Sun had formed with a brown dwarf companion similar to “Resyx” or “Thirdseen”* here (i.e. 8 x mJ @ 300 AU ~ish) would we be able to see it now?

    (Will WISE pick it up soon if it does exist is another thought too! :-) )

    Would we know about it & could it cause mass extinctions by wandering into the cometary cloud in the Edgeworth (Kuiper) Plutonian zone belt?

    —————

    * “Fourthseen” being a possible name for 1RSX J160929.1-210524 derived from its significance as the Fourth exoplanert we’ve directly Seen natch. (behind 2M1207 b, Fomalhaut b and the worlds orbiting HR 8799 or “Gadolabove” – see comment #13 here.

  31. Messier Tidy Upper

    For more info on a couple of things mentioned, if folks are curious.

    See :

    http://en.wikipedia.org/wiki/Debra_Fischer

    For my example of a “planet hunter”astronomer who I’d get to name the world’s she finds.

    More via the BA blog on the colours of “Brown dwarfs” :

    http://blogs.discovermagazine.com/badastronomy/2010/01/29/the-case-of-the-brown-star-thats-really-red-or-possibly-blue/

    Which includes links to some other really excellent B blog threads “Welcome to our tiny family” & “Dim, faint, and small is no way to go through life, son” & “Astronomers weigh in on teeny stars” at the end.

    Plus the Nemesis hypotheis wiki-page here :

    http://en.wikipedia.org/wiki/Nemesis_(star)

    Which makes it apparently *much* further out than 300 AU – apparently the idea is for the hypothetical brown /red dwarf to be located 50,000 to 100,000 AU (about 1-2 light years) away instead!

  32. Messier Tidy Upper

    Finally, on just a couple of other points incidentally raised, if folks are curious – see :

    http://www2.ess.ucla.edu/~jewitt/kb.html

    & from the introduction go to the “Why is it called that?” (The pronunciation and the history of the name) link where David Jewitt hunter of Trans-Neptunian ice dwarfs notes :

    The problem with Kuiper Belt is that Kuiper did not, by any objective reading, really predict the object to which his name is given. Kuiper’s paper refers to a primordial set of bodies that he supposed were scattered out to the Oort Cloud by massive Pluto, so that if taken at face value his paper predicts there should be nothing where we now see Kuiper Belt Objects. Kuiper in fact anti-predicted what we now call the Kuiper Belt. .. [SNIP! Mention of earlier independent papers by Kenneth Edgeworth & others. follows] … Presumably, the intent should be to do the right thing by attributing credit where it’s due. Unfortunately, it’s not clear to me where, if anywhere, proper credit is due. Just hand-waving on the possibility that there might be something “beyond Pluto” is not sufficient. Some of the above seem a bit like the predictions of Nostradamus: read into them what you will. If anything, I would say that J. Fernandez most nearly deserves the credit for predicting the Kuiper Belt based on clear statements and physical reasoning. His 1980 paper (Monthly Notices of the Royal Astronomical Society, 192, 481-491) is worth a careful read. …

    [Emphasis added.]

    & for more on the star named Peacock (Alpha Pavonis) see :

    http://stars.astro.illinois.edu/sow/peacock.html

    PS. Very glad there’s no limit on the number of times folks can comment on the one thread! ;-)

    Know I’ve posted a lot here but there’s just an awful lot of thoughts inspired and things to say stemming from the OP here on an area I really love. Thanks BA. :-)

  33. lordbubonicus

    @Messier Tidy Upper: I like this idea of splitting very long comments into chunks. You’ve got enough for another blog post there! I think that it certainly makes it more likely that people will read the whole thing.

    You’ve done an excellent job summarising the possibilities for naming planets. I have to say that one of the first things that people always ask me when I say that I work on exoplanets is “Do you get to name the ones that you find?”. They’re always disappointed when I explain the naming convention to them. So I agree that something should be done to name the planets. In fact, a paper popped up on the ArXiV a while back dealing with this very issue: http://arxiv.org/abs/0910.3989 I didn’t see you link to it, so apologies if you did. The author basically deals with names according to your suggestion 1a, with a little bit of 1b for good measure.

    I think that the problem, as has been pointed out a couple of times already, is the sheer quantity of planets that we’re dealing with. I think that because of this, your idea 4 isn’t really workable. I know that there are a lot of scientists working in the exoplanet field, but there are still too many planets to avoid repetition of names, which I personally view as a bad idea. In any case, I think that we need some kind of universal naming convention or guidelines.

    One suggestion that I don’t think you covered, which could work, would be to name the systems, a la Star Trek (don’t shoot me!). Then refer to the planets by letters according to their position in the system. That doesn’t really do much for the numbers of names required at the moment, as the vast majority of the planets are in single systems currently, but could well be important for the future as more planets are discovered in existing systems.

  34. keplerlover

    @Messier Tidy Upper Yep, the WISE team says they’ll definitely detect Nemesis if it exists (they prefer another name, which I can’t remember, though it is more benign). Personally, I prefer Shiva (suggested by Steven J. Gould ) or Kali, his consort.

  35. Michael Kingsford Gray

    A star that is only 1 inch in diameter?
    Tell ‘em they’re dreamin’!

  36. @MTU:

    I still say we name it Bob.

  37. Nigel Depledge

    Daffy (23) said:

    RAF, that is exactly why I am curious. If they find the same pattern around another star, it would make it more than coincidence, I should think. Something caused it…for reasons I can’t explain, it has always fascinated me. The question is, is it unique?

    Actually, the “Bode’s law” pattern around our own star is iffy, at best.

    Having read the Wikipedia article on Bode’s “law”, I find that it only works if we demand that Ceres be classed as a planet, but that no other object in the asteroid belt is counted (so what makes Ceres so special compared with all the other spheroidal asteroids in that region of space?). Also, Neptune doesn’t fit, and neither does Pluto. However, even if one accepts Pluto as a planet, Bode’s “law” cannot account for all the other pluto-sized KBOs in that part of the solar system. If Bode’s “law” stands, planet-sized objects should be progressively more widely spaced as one looks farther and farther from the parent star. The entire Kuiper belt gives the lie to this idea (even if one only counts KBOs that are Pluto-sized or larger).

    Interestingly, if one ignores Neptune, then Pluto fits the curve. That obviously demands that we question the whole thing. Neptune is quite obviously a planet (whatever the definition of the term “planet”, it really should include Neptune and similar objects), whereas Pluto is a marginal case.

    The apparent fit of Bode’s “law” up to and including Ouranos (I find I prefer this spelling, as it fits the original pronunciation better) is an illusion. Ceres isn’t a planet, but Bode’s “law” demands that it be counted as one. Many asteroid belt objects are not much smaller than Ceres, but Bode’s “law” demands that they be discounted. If one discounts Ceres, or includes several asteroid belt objects, the illusion of Bode’s “law” falls apart completely.

    BTW, for those who can’t be bothered to go and read it on Wikipedia, Bode’s “law” states a formula for the distance of planets’ orbits (their semi-major axis) from their parent star. In its simplest form, counting outwards from the sun, each planet is roughly twice the distance from the sun as the previous one. It holds for Mercury, Venus, Earth and Mars. If one counts Ceres as a planet (and no other asteroid belt objects), it also holds for Ceres, Jupiter, Saturn and Ouranos. But it really is a case of forcing the data to fit the curve, rather than some fundamental rule about forming planetary systems.

  38. Nigel Depledge

    Messier tidy upper (26) said:

    Its hard to pronounce, memorise and talk about a string of numbers as a real place.

    To relate to and come up with adjectives for an numeric-alpha-soup.

    Yeah. I guess that’s why the residents of LV-426 decided to call it Acheron.

  39. #23 Daffy:
    The so-called “Bode’s Law” is meaningless. Nothing “caused” it, because it isn’t a “law” at all. Full stop, end of!
    Your argument about “if we find the same pattern around other stars” is totally pointless, because – get this – it doesn’t even “work” in our own Solar System!
    A little background, for those who don’t know. Firstly, it should really be called “Titius’ Law”, as Titius first proposed it; Johann Bode merely publicised it. That is, if it still deserves to be called anything – which it doesn’t.
    This so-called “law”, publicised in the 18th Century, is simply a supposed numerical relationship between the distances of the planets which were known at the time, i.e. those as far as Saturn. Uranus and Neptune hadn’t yet been discovered. It has no physical meaning whatsoever, and as far as I know, even Bode himself never claimed that it did; he publicised it simply as an interesting curiosity.
    However, some people of the time believed that it did, or might, have some unknown physical meaning. The fact that one of the numbers in the sequence – the one between those corresponding to Mars and Jupiter – had no known corresponding planet, led some to speculate that there might be an as yet unknown planet in that position, and a society known as the “Celestial Police” was founded to search for it.
    We do of course have the asteroid belt – which was also unknown at the time – which corresponds very roughly to Bode’s “missing planet” position – but no planet. When Ceres, the first asteroid, was discovered, it was initially hailed as a success for Bode’s Law, until
    a. It was found to be far too small to be a bona fide planet.
    b. More asteroids were found.
    ( Ironically, Giuseppe Piazzi, who discovered Ceres, wasn’t a member of the “Police”. )
    But then we come to the outer planets. If there was really anything in the “law”, then you would expect that extending the numerical sequence beyond Saturn would “predict” the positions of those planets which were yet to be discovered, would you not? But it doesn’t! The distance of Uranus doesn’t correspond at all closely to the next “predicted” value, and those of Neptune and Pluto ( which some still regard as a planet, despite the IAU’s demotion ) are absolutely nowhere near.
    So I say again – “Bode’s Law” is meaningless nonsense.

  40. Nigel Depledge

    @ Messier tidy upper –

    I broadly agree that there should be some convention whereby we can assign names to exoplanets.

    Whatever system we end up with, I think it needs to meet the following criteria:
    (1) To be able to provide many millions of names (we have no idea how many exoplanets we may eventually discover)
    (2) To allow for planets to be discovered in an inconvenient sequence (because if we assign a name and number based on the discoverer’s name we could end up with, for example, Fisher-1 and Fisher-3 orbiting the same star, while Fisher-2 orbits a completely different star, which would be terribly confusing).
    (3) It could do with avoiding similar-sounding names (it was a long time before I could remember which planets were orbited by Titan and Triton, for instance).
    (4) Some kind of letter or number component could be included, but in a limited fashion (as in “this is Zaphod Beeblebrox from Betelgeuse V, you know, not bloody Martin Smith from Croyden”).

  41. Sorry, folks – #35 Nigel beat me to it by minutes!

  42. Tom K

    Bode’s Law is as much a law as Moore’s Law, which is to say, not at all. It’s just an observation. Yet people often cite Moore’s Law as if it’s a valid predictor.

  43. GK4

    @Andy at #29,
    I agree that we should wait until we have confirmations.

    @Nigel at #38,
    You raise good points. I think my system has the potential for meeting your first two criteria. Although, I would avoid naming things after real people. What if “Fisher” was a jerk? :)

    As for similar or identical names, we already deal with that problem on Earth by using more than one geographical reference. For example, I can clarify the difference between two Londons by including “England” or “Ontario”. Couldn’t the same work for stars and exoplanets, once the full name is provided in a given article or paper?

    Phil already did this in his post. There are more than 100,000 stars in the 1st ROSAT X Survey, so I doubt this is the only one that begins “1RXS 1609″. It’s a shorthand to facilitate discussion.

    And MTU/ex-StevoR, look into why these designations have so many digits. This will clarify the scope of the challenge. But yes, I agree that proper names are easier for journalists and the public to grasp than long strings of numbers.

    Does anyone know if I should take my idea directly to the relevant IAU Working Group, or should I start smaller?

  44. Daffy

    Wow. Not sure why people are so emotional about Bode’s Law; even with the cracks in it, I just find it curious. But I won’t mention it again, I promise.

  45. Messier Tidy Upper

    @37. Kevin Says:

    @MTU: I still say we name it Bob.

    I’d settle for Bob over 1RXS J160929.1-210524 anyday! ;-)

    @44.GK4

    Does anyone know if I should take my idea directly to the relevant IAU Working Group, or should I start smaller?

    No idea. But what’s your system again?

    @ 41. Nigel Depledge & 35. keplerlover : Thanks. :-)

  46. ND
  47. Jon Hanford

    MTU & keplerlover:

    “@Messier Tidy Upper Yep, the WISE team says they’ll definitely detect Nemesis if it exists (they prefer another name, which I can’t remember, though it is more benign).”

    Davy Kirkpatrick, a member of the WISE science team at Caltech, says that Tyche is now their preferred name for Nemesis:

    “There is some speculation amongst scientists that such a cool body, if it exists, could be a brown dwarf companion to our sun. This hypothetical object has been nicknamed “Nemesis.”

    “We are now calling the hypothetical brown dwarf Tyche instead, after the benevolent counterpart to Nemesis,” said Kirkpatrick. “Although there is only limited evidence to suggest a large body in a wide, stable orbit around the sun, WISE should be able to find it, or rule it out altogether.” ( http://www.physorg.com/news196619256.html )

    That’s all well and good, but……….”258 Tyche is a relatively large Main belt asteroid”: http://en.wikipedia.org/wiki/258_Tyche

    Looks like another possible source of confusion (if it’s found, of course!) :D

  48. olderwithmoreinsurance

    @Jon Hanford #48 Nice catch on the asteroid Tyche! I think I tend not to remember names I don’t know how to pronounce…..So that name will definitely be ruled out by the IAU since it’s already in use. Even if Shiva, Nemesis etc. doesn’t exist, the WISE team might still find a brown dwarf closer than Proxima Centauri, which would be pretty cool.

  49. olderwithmoreinsurance

    And on the question of naming extrasolar planets: I strongly suspect that the current convention will hold at least until we can actually resolve some thru space-based interferometry and/or obtain detailed spectra of earth-like extrasolar planets. THEN some of the planets will seem like real worlds to many of us. The current system is simple and is pretty descriptive in that it tells us where the planets are, and in what order out from their star (it’s possible that’s violated in a few cases, but I’m not going to dig thru the extrasolar planet encyclopedia to find out).

  50. #11 Messier, #38 Nigel:
    I’m puzzled as to why you prefer to call Uranus “Ouranos”. Yes, that’s the original Greek spelling, but Uranus is the Latinised version.
    The Greek and Roman mythologies were equivalent, with different names for the same deities. All the names of the planets are the Roman versions.
    Ouranos/Uranus is one of the few deities who share the same name in both mythologies, with just the spelling changed. So in line with the convention of using the Roman names for planets, Uranus is correct, and Ouranos isn’t.

  51. andy

    Actually the Roman deity equivalent of the Greek Οὐρανός is Caelus, though Caelus was more a literary personification than worshipped as a god: Οὐρανός was far more important in Greek mythology than Caelus was in the Roman mythology. “Uranus” is a transliteration, not an equivalent.

    As for Wladimir Lyra’s proposed extrasolar planets nomenclature system mentioned by lordbubonicus @ #34, the justification for restricting the nomenclature to Greek/Roman mythology seems to be “well we’ve never acknowledged other cultures before in our planetary naming system, so why start now?”. Very unconvincing to me. As for nomenclature based on constellations this seems silly to me: why should the name depend on the vantage point of the system from Earth. There are also a few cases where Lyra gives some perhaps inappropriate names: e.g. he gives the name Phlegethon (the river of fire in the underworld) to the habitable-zone gas giant HD 28185b. That name would perhaps better suit a hot Jupiter.

  52. GK4

    @Andy, at #53,
    – There are already non-Greek, non-Roman names for dwarf planets in our own solar system. Makemake was a Rapanui god, and Haumea was a Hawaiian goddess.

    @olderwithmoreinsurance, at #51,
    – I believe that the letters “b”, “c”, etcetera, for extrasolar planets are based on the order of discovery, not the order out from their star. See the Gliese 581 system for an example.

    @MTU, at #46,
    – My naming system is based on the assumption that any extrasolar planet (and its “mother” star) that we find will be cataloged. Assign each catalog a unique set of letters which will serve as a “prefix” for the star or planet’s name. The numbers of the designation are then converted to letters using one of a couple of different methods. The discoverers get to choose the results they like best.

    More names are made available as further scrutiny of a system gets that system listed in newer catalogs. So, I don’t think we’d run out of names for a long time. And if done right, a name can be converted back into the original catalog designation.

    There are a lot of details, of course, and a few other ideas for special cases. It’s pretty wonky, really. For the last couple of years I’ve been trying out various methods to see what results work best. I’m reasonably happy with what I’m getting, so I asked folks here for feedback with my examples above.

  53. olderwithmoreinsurance

    @GK4, you’re right, but most of the time the order of discovery goes from closest to furthest, since it’s easier to discover the close ones first: transit likelihood comes up, radial velocity amplitude goes up, time base of observations needed goes down. that’s why I said I thought there were exceptions, but I don’t think there are a lot of them (so far). In any case, I don’t have a problem with the current system. It’s MUCH better than the system for naming variable stars, for example. Probably more important is the fact that none of the people actually finding the planets or doing other work on them seem to have a problem. I’d wager my maximum amount (American quarter) that the current system isn’t changed within the next decade, even though the number of extra-solar planets known will likely increase by at least a factor of 10.

  54. olderwithmoreinsurance

    @GK4, you’re right, but most of the time the order of discovery goes from closest to furthest, since it’s easier to discover the close ones first: transit likelihood comes up, radial velocity amplitude goes up, time base of observations needed goes down. that’s why I said I thought there were exceptions, but I don’t think there are a lot of them (so far). In any case, I don’t have a problem with the current system. It’s MUCH better than the system for naming variable stars, for example. Probably more important is the fact that none of the people actually finding the planets or doing other work on them seem to have a problem. I’d wager my maximum amount (American quarter) that the current system isn’t changed within the next decade, even though the number of exoplanets known will likely increase by at least a factor of 10. The great majority of exoplanets now known orbit stars in the Henry Draper catalogue, since that has a limiting apparent magnitude of around 9 or so. Kepler is changing that so its discoveries and those of CoRot are being named for those satellites, (as are those from some ground based instruments such as WASP and HAT) even though all those stars are otherwise catalogued. With modern databases that currently exist, none of this seems to be much of a problem. I like knowing at a glance what instrument and/or groups made the discovery, as is possible with the fainter stars.

  55. GK4

    @olderwithmoreinsurance,

    I agree that the current system of designations works well for the professionals. But I don’t see it working much longer for laypeople or the media.

    I fear that when an Earth-like planet is found, some “wit” will make up a stupid name for it (“Earth 2.0″ or “Eden” or a name from recent fiction). People being what they are, the name might even catch on, even it if makes no sense. Remember “Xena”?

    I’d rather have a system in place where the IAU and exoplanet researchers can generate a proper name as needed, and keep the process coherent.

    I could be wrong. After all, people have, until recently, memorized and recited multiple telephone numbers accurately. But I think my eight-year-old nephew would have an easier time learning and talking about “Upziatl” than about “1RXS J160929.1-210524″.

    By the way, I even have a system for giving proper names to variable stars and their planets. Perhaps you’ll like “Valibien” over “HO Librae”?

  56. Pi-needles

    The BA has beaten Wikipedia to the punch – Today in their main page “In the news” box they have:

    Collaborating astronomers confirm the orbital motion of the first directly imaged exoplanet near a sun-like star.

    as the first item. Sirius – the dogstar & brightest in our skies other than our Sun itself – is “Today’s featured article” on Wikipedia too. :-)

    @57. GK4 Says:

    Remember “Xena”?

    You mean this Xena:

    http://media.photobucket.com/image/xena%20the%20warrior%20princess/plucktheroses/xena_-_warrior_princess.jpg

    How could we forget her? ;-)

  57. Messier Tidy Upper

    @34.lordbubonicus & (#54 & 57) GK4 & (#51 & 56) olderwithmoreinsurance & (# 53.) andy & 48. Jon Hanford : Thanks. Good comments from y’all which, alas, I haven’t got time to discuss further right now but may do later. :-)

    @ 52. Neil Haggath Says:

    #11 Messier, #38 Nigel: I’m puzzled as to why you prefer to call Uranus “Ouranos”. Yes, that’s the original Greek spelling, but Uranus is the Latinised version. (emphasis added.)

    That bit in bold is good enough reason for me – Ouranos = a greek god so why not use greek spelling rather than latinising it! ;-)

    Plus Ouranos sounds better anyhow & stops it being a joke! There’s even facebook group (I’m a member) calling for the Ouranos spelling to be adopted. :-)

    @ 47. ND Says: “Arrakis …”

    Good name but probably not for this particular exoplanet. :-)

    I posted this before on an earlier BA blog thread but if you missed it :

    ***

    Arrakis is actually a real star name. :-)

    (Frank Herbert did his research! ;-) )

    Arrakis is the proper name for Mu Draconis which is located near the head of the “dragon” roughly in line with Rastaban (Beta Draconis) and forming a triangle with Kuma (Nu Drac.) :

    ” .. a close double star with cream coloured components each of magnitude 5.8. A telescope of 100 mm aperture or more and high magnification is needed to separate the stars, which orbit every 480 years.

    Source : Pages 138-139, Collins Guide To Stars & Planets, Ian Ridpath & Wil Tirion, Collins, 1988. (First published 1984.)

    There is a slight confusion here in that Arrakis is also listed by the ‘Alrakis’ variant of its name in a later updated edition of Collins guide which also notes :

    Mu Dra 17 h 05m+54.5 degrees, (Alrakis), 88 l.y. away, is a close double star with matching cream- coloured components of mag. 5.6 and 5.7 which orbitevery 670 years. The two stars are currently moving apart and becoming progressively easier to split in small apertures, although high magnification will be needed.

    Source : Pages 144-145, Collins Guide To Stars & Planets, Ian Ridpath & Wil Tirion, Collins, 2007. (First published 1984.)

    I’m sure Celestia or (most?) other planetarium software will be able to provide extra, even more up to date info. (such as spectral class, maybe radius, age, luminosity, mass & other details) if folks are curious to find out more.

    Neat thing is that Arrakis is a real star which can be seen in our night sky – although whether the planet of spice and sandworms as Frank Herbert imagined orbits it is somewhat less than 100% certain! ;-)

    ***

    Hope its okay to post this info. again in this context. My apologies if not.

  58. andy

    Ouranos = a greek god so why not use greek spelling rather than latinising it!

    If you want the original Greek spelling it would be “Οὐρανός”, not “Ouranos”, as Greek uses its own alphabet – by converting to the Latin alphabet you are inevitably going to have to do some “Latinisation”. The conversion between the two is not necessarily going to produce “Ouranos” – the Greek letters do not necessarily correspond precisely to the letters in the Latin alphabet, and the value may change depending on whether the letter is part of a diphthong, or its position in the word. For example, while gamma is usually stated to be equivalent to g, if it comes before another consonant it becomes n, thus “Ἐγκέλαδος” is transliterated to “Enceladus” rather than “Egkelados”. Bearing this in mind, “Uranus” is a perfectly good transliteration, despite the fact that several of the vowel sounds do not correspond to the letter you might expect from a naive mapping from one language to another.

    There are already non-Greek, non-Roman names for dwarf planets in our own solar system. Makemake was a Rapanui god, and Haumea was a Hawaiian goddess.

    Indeed – however I was pointing out Wladimir Lyra’s arguments, not my own: he explicitly states he does not think this multiculturalisation of nomenclature to non-Western cultures is a good idea.

  59. MaDeR

    I do not think custom names for exoplanets are worth it at the moment.

    I would start from something that is worth naming, like exoplanet in habitable zone with confirmed atmosphere disrepancy unexplainable with abiological means. This obviously mean we have to wait long time, two or three decades.

    Until then, namig exoplanets makes no sense. There WILL be too much of them. We do not have custom names for 99,99…% of stars i n galaxy and you all want to name exoplanets?? Something is not right there.

  60. Curious

    A cool name for the first Earth-like world could be “Aurora”

  61. Nobu

    It is not even the first direct image of a planet orbiting a sun-like star taken by a telescope on Earth.
    The first one had been taken with Subaru back in 2002.
    “H-Band Image of a Planetary Companion Around HR 8799 in 2002″ Fukagawa et al., The Astrophysical Journal Letters, Volume 696, Issue 1, pp. L1-L5

  62. russell

    oy calling it planet bob …memories of a good show
    this is good but its so close to the star to be habitable

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