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Space News

More to the North Star Than Meets the Eye 179

Posted by ScuttleMonkey from the polaris-trifecta dept.
__roo writes "By stretching the capabilities of NASA's Hubble Space Telescope to the limit, astronomers have photographed the close companion of Polaris for the first time. This sequence of images shows that the North Star, Polaris is really a triple star system. 'The star we observed is so close to Polaris that we needed every available bit of Hubble's resolution to see it'" said astronomer Nancy Evans of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts."
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More to the North Star Than Meets the Eye More

More to the North Star Than Meets the Eye

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  • Just Beyond The Capabilities of My 125 ETX (Score:3, Insightful)

    by ackthpt ( 218170 ) * on Monday January 09, 2006 @02:36PM (#14429274) Homepage Journal
    Cool as beans, but still won't save dear old Hubble, will it? The one thing Hubble can't find, no matter how much straining of limits is the willingness of NASA to save the faithful servant. With recent budget cuts for Katrina and the on-going war, don't hold your breath for a reprieve.

    they should nickname the mini star, Cooper

    Got an ETX for Christmas? You should know this site. [weasner.com]

    • Re:Just Beyond The Capabilities of My 125 ETX (Score:4, Informative)

      by artitumis ( 934987 ) on Monday January 09, 2006 @02:43PM (#14429350) Homepage

      The Hubble already has a repalcement in the works. It is called The James Webb Space Telescope and is scheduled to go up in 2013. More about the JWST [nasa.gov]

    • Re:Just Beyond The Capabilities of My 125 ETX (Score:5, Interesting)

      by ajs ( 35943 ) <{ajs} {at} {ajs.com}> on Monday January 09, 2006 @02:52PM (#14429433) Homepage Journal
      Actually, I'm not sure that there's anything in this observation that Hubble is needed for. AO is limited in the ultraviolet, but this observation could have been made in the visisble spectrum, I would expect. As such, any of the more recent large telescopes with AO should have been able to make this observation. It just so happens that it was done with Hubble instead.

      For those not aware, AO is "Addaptive Optics". This is how you use ground-based scopes, but compensate for the atmosphere. It usually involves deforming a physical mirror, though I think there are some AO systems that work purely digitally. I'm not sure. IANAA.

      AO was perfected after Hubble went up, and many ground-based scopes have gotten imaging that's just as detailed (more so in some cases) as Hubble is capable of. I have an astronomer friend who was fond of showing off some photos that he had from AO scopes off of relatively old, retrofitted systems that he claimed were better imaging that Hubble had been able to get from the same objects.
    • Cool as beans, but still won't save dear old Hubble, will it? The one thing Hubble can't find, no matter how much straining of limits is the willingness of NASA to save the faithful servant. With recent budget cuts for Katrina and the on-going war, don't hold your breath for a reprieve.

      Or, better yet, we could scrap hubble and use the money we saved to build a telescope twice as powerful for half as much, including giving it a properly ground mirror this time.

  • Not Informative (Score:5, Funny)

    by saskboy ( 600063 ) on Monday January 09, 2006 @02:39PM (#14429306) Homepage Journal
    "sequence of images shows that the North Star, Polaris is really a triple star system."

    Damit! OK, so which star do I point my sextant at then if I'm trying to find my latitude? Modern science complicates things so much!

    [Yes this is a joke, for those who don't get astronomy humour.]
    • Call me a luddite but I still use an astrolabe....
    • Venus. Not a star but ubiqutous in terms of visbilty from most latitudes...
    • Damit! OK, so which star do I point my sextant at then if I'm trying to find my latitude?

      the Sun... when you take your Noon sighting...

  • Looks like the Bard screwed that up... (Score:3, Funny)

    by Gandalf_the_Beardy ( 894476 ) on Monday January 09, 2006 @02:40PM (#14429320)
    "I am as constant as the Northern Star." Always though Caesar was a little unstable and went round and round in circles....

  • More. (Score:2)

    by Racher ( 34432 )
    Another day, another star. Yet this one is important because it is the companion of Polaris? When do we get to see the edge of the universe cafe?

    • Re:More. (Score:3, Informative)

      by hattig ( 47930 )
      As the FA points out: "it is the nearest Cepheid variable star. Cepheids' brightness variations are used to measure the distances of galaxies and the expansion rate of the universe"

      So quite useful in astronomy.
      • As the FA points out: "it is the nearest Cepheid variable star. Cepheids' brightness variations are used to measure the distances of galaxies and the expansion rate of the universe"

        Well a cepheid is a star with variations in brightness... um.. excuse me.... UM? IANAAP, but how do they tell excatly what is a cepeid? I'm just wondering... could a companion orbiting closely to its parent star that was not detected previously have created the conditions that were previously attributed to the parent as being a

    • Re:More. (Score:2, Informative)

      by Anonymous Coward
      Actually I think what you actually meant was the "Restaurant at the End of the Universe". And the name refers to the temporal aspect, not locality.

    • Re:More. (Score:3, Funny)

      by AviLazar ( 741826 )
      When do we get to see the edge of the universe cafe?

      When Starbucks agrees to the contract negotiations.
  • Comment removed based on user account deletion
    • My God, it's full of stars!

      Are you suggesting that, in orbit around a moon of an outer planet in the Polaris system, we'll find an alien artefact which, if docked with by a human ship, will transport it instantly across half the galaxy to make contact with its creators?

      Excuse me.

      * ring ring. ring ring *

      Ah yes. Is that New Rossyth? Excellent. Could you get me Meredith Argent on the line please? Thank you. Yes. I'll hold. Hello? Meredith? Yes. Look, can you get hold of Mic Turner at short notice? And

    • My God, it's full of stars!

      Lately I have been reading the Apollo lunar surface journal [nasa.gov]. I am up to Apollo 15 which included Dave Scott on the crew. I find it totally wierd to read lines like:

      115:31:01 Parker: Roger. Morning, Dave. Waking you up an hour early because we've got a little problem on-board we need addressed.

      My mind always fills it in with something about the AE35 antenna pointing module.

  • According to google calculator:

                      2 000 000 000 miles = 21.5155818 Astronomical Units

    which puts it just inside the closest approach of Saturn, but well outside Jupiter's orbit.
    • I don't know much about astronomy, but putting it even on *that* scale makes me say, "wow, that is really, really close!"
    • I don't know the average distance between twin stars, but considering that they're *stars*, not planets, that does seem pretty close to me.
      • there seems to be a renewed set of discoveries in the Bears recently? First the midsized black-hole in Ursa Major, and now the new companion star in Ursa Minor.

        Interesting. I didn't think we would find anything else in this region of the sky....
    • The closest star to ours is ~278,000 AU away. So relatively speaking, yes, 21.5 AU is indeed "close".
      • Well, compared to other binary stars ~21 AU isn't abnormally close; consider (numbers from wikipedia):

        Procyon [wikipedia.org] A and B are an average of 16 AU apart.
        Alpha Centuri [wikipedia.org] A and B range between ~11 and ~36 AU. However, Proxima Centuri orbits at 4.22 light years or 266,871.415 Astronomical Units.
        Algol [wikipedia.org] has two stars only 0.062 AU apart, as well as a third star at 2.69 AU.
        Sirius is 20 AU [wikipedia.org]

        and you cold calculate more (Beta Cygni) knowing the angle between them or orbital periods (an excercise left to someone who knows th
    • Yes, but Saturn is a planet of Sol (our sun); for another star to be at this distance is "close." Our nearest star is Proxima centauri [wikipedia.org], a mere 268 000 AU away (approximately).
      • Yes, but Saturn is a planet of Sol (our sun)

        I just gotta nit pick this. "Sol" is latin for "Sun", "our sun" would be "nostrus Sol". Which is kind of redundant, because there's only one Sun... ours.

        If you want to say that Sol is our star, then yeah, that works, but "our Sun" is a bit redundant.

        Crap, I wanted this to be funnier... :(
    • Polaris A is big. Really, really big. You may think that it's a long walk...

      Sorry.

      But seriously, Polaris A [domeofthesky.com] is a supergiant, about 2400 times as bright as the sun, and Polaris Ab is a main sequence star. 22 AUs is really close for a couple of stars that size!
      • Sounds like just the right distance for a proto planetary-system disk to condense, and instead of forming a few gas giants like Jupiter and Saturn in there among the rocky planets, maybe some of the gas giants merged and became massive enough to become a small star... So it's probably common, even...

        It would REALLY blow my mind to see two stars of Polaris A's type so close together! That would be wild!

    • ...21.5155818 Astronomical Units

      which puts it just inside the closest approach of Saturn, but well outside Jupiter's orbit.

      That depends a lot on perspective. As distances between stars go, that's really quite close. Keep in mind that the sun is a fairly small star. For comparison, however, compare this orbit to the diameter of Betelgeuse [solstation.com].

      Admittedly, Betelgeuse is huge -- a supergiant, AAMOF. Nonetheless, we're talking about a size that would basically put the two into direct contact --though, admi

  • ummm... (Score:4, Insightful)

    by heatdeath ( 217147 ) on Monday January 09, 2006 @02:45PM (#14429359)
    Am I the only one who doesn't think that that's very clearly a triple star from the pictures? =P The title of the article made it look like the light we see from it is actually from three really close together stars...but it seems like we're only seem polaris A, since the smaller ones are so tiny.
    • There is Polaris A (a large star), then Polaris Ab (a small dot to the bottom-right of Polaris A, that overlaps the glow of the main star).

      Then, far to the bottom right, quite separate from Polaris A is Polaris B.

      They are all visible in the picture.

  • ASCII Picture Mirror (Score:5, Funny)

    by big_groo ( 237634 ) <groovis AT gmail DOT com> on Monday January 09, 2006 @02:48PM (#14429383) Homepage
    Polaris ---> O
    Polaris Ab---->.

    Polaris A --------->o
  • Is it just me, or does that picture make it look like Polaris just has some version of an interstellar zit? Maybe it's a boil...

  • Second star inside Neptune's orbit (Score:5, Informative)

    by RobertB-DC ( 622190 ) * on Monday January 09, 2006 @02:49PM (#14429398) Homepage Journal
    From the article: "The companion proved to be less than two-tenths of an arcsecond from Polaris... At the system's distance of 430 light-years, that translates into a separation of about 2 billion miles."

    I did a little googling, and found that Neptune's orbit is just over 2 billion miles from the Sun. So for reference, Hubble has directly imaged two distant objects that could fit inside our own solar system.

    I think they could have gotten more "Oomph!" from their press release if they'd mentioned this fact. Also, they may have wanted to measure the distance in a standard publicity unit, such as roundtrip NY-LA distances ("A little over 350,000 round-trips from New York to Los Angeles").
    • I think they could have gotten more "Oomph!" from their press release if they'd mentioned this fact. Also, they may have wanted to measure the distance in a standard publicity unit, such as roundtrip NY-LA distances ("A little over 350,000 round-trips from New York to Los Angeles").

      Pff! you and your NY-LA distances... My car gets two football fields to a bathtub, and that's the way I like it!
    • Also, they may have wanted to measure the distance in a standard publicity unit, such as roundtrip NY-LA distances ("A little over 350,000 round-trips from New York to Los Angeles").

      I think to appreciate it, I need it in terms of "The Books of the Library of Congress laid end-to-end."

  • It's just drifting south over Siberia.

  • Some perspective... (Score:2, Informative)

    by Anonymous Coward
    TFA states that the close companion orbits at about 2 billion miles, or about 21.5 AU from the parent. That is a bit more than the orbit of Uranus (19.5 AU) in our own system. They had to stretch the Hubble to its limit to see something as bright as a STAR that was far enough away from the parent to fit most of our entire solar system inside. 490 light years is a long way away.

  • Gah.... (Score:3, Funny)

    by Anonymous Coward on Monday January 09, 2006 @02:57PM (#14429472)
    That's space for ya, nothing for millions of miles, and all of sudden, three stars at once.
  • Triple star systems degrade by kicking out one of the stars so the remaining two stars can settle into a stable binary system.

    Likely the small nearly hidden star is similar to Jupiter.

    • Re:I doubt this a a triple star system (Score:5, Informative)

      by hcg50a ( 690062 ) on Monday January 09, 2006 @03:16PM (#14429641) Journal
      Your first comment is true in the general 3-body problem, but certain cases are actually stable over a long period of time. Namely, when two of the bodies are in a very tight orbit which is not significantly perturbed by the 3rd body.

      So, the system approximates a stable two body system.

      Another similar case is 4 stars, where there are two close pairs in orbit around each other. This idea can be extrapolated to any number of stars as long as each pair is not significantly perturbed by its non-pair neighbors.

    • Re:I doubt this a a triple star system (Score:5, Interesting)

      by coyote-san ( 38515 ) on Monday January 09, 2006 @03:23PM (#14429705)
      Where did you get this? There are many reasonably stable three-plus body systems. ("reasonably stable" meaning that they'll last the lifetime of the stars, but could still be disrupted by passing stars, etc.)

      The classic example is a close binary with a distant third. The distant star essentially sees the binaries as a point. The binaries see the gravitational attraction of the third star as essentially flat (since the tidal forces drop off as 1/r^3). This doesn't mean non-zero, it just means that the attraction of the "near" star won't be higher than the attraction of the "far" star. IIRC that's why the moon is slowly pulling away from the earth -- the sun is slowly pulling the earth and the moon apart.

      Another example is a pair of close binaries. Again each binary is overwhelmingly dominated by its pair, with the gravitational attraction of the other pair as essentially flat.

  • Odd phrasing (Score:3, Interesting)

    by Kelson ( 129150 ) * on Monday January 09, 2006 @03:03PM (#14429520) Homepage Journal
    "With Hubble, we've pulled the North Star's companion out of the shadows and into the spotlight."

    Of course, stars are easier to see surrounded by shadow than in the glare of a spotlight. Shouldn't this say, "We've pulled the North Star's companion out of the spotlight and into the shadows?"
  • No wonder I never got my orienteering merit badge!
  • The North Star: Robots In Disguise
  • You know, that part about splashing Hubble into ocean?
    Stupid bastards.

    Hubble is the very best thing Nasa has ever put into orbit around Earth.
    Leave it the f**k alone..

    • Leave it the f**k alone..

      I think that's primarily the problem. Failing electronics and gyroscopes mean you can't just 'leave it alone' or it will become useless, and also a potential danger. Hubble is also in LEO and as such needs its orbit boosting on a regular basis.

      So you can't just leave it the fuck alone, you have to make extremely expensive manned missions to continualy repair and resupply it. Of course, there is another option. De-orbit it while we still have control and can safely do so and with

  • no wonder I've been getting lost! (Score:3, Funny)

    by peter303 ( 12292 ) on Monday January 09, 2006 @03:51PM (#14429966)
    I've been following Polaris #3 instead of Polaris #1.
  • I'm sure we'll be hearing from the Religious Right about this. "The Star that appeared on the eve of our Savior's birth is actually a trinity - a three-in-one! Just like Jesus! This just proves that it's true!"
    • Most of the whackjobs deny the idea of a trinity. That's Catholic Dogma.
      • Most of the whackjobs deny the idea of a trinity. That's Catholic Dogma.

        I think you're mistaken. JWs don't believe in the Trinity, but as far as I'm aware, most other Christian-ish religions/denominations do.
    • "The Star that appeared on the eve of our Savior's birth is actually a trinity - a three-in-one! Just like Jesus! This just proves that it's true!"

      Polaris suddenly appeared two millenia ago?
      • According to the Christian mythology, it did. It's the star that the wise men supposedly followed to find Christ... a star that had never been seen before. Of course, if they had followed it, they would've been quite cold.
  • "More to the North Star Than Meets the Eye"

    Well I'd certainly hope so, it just looks like a small white dot to me...
  • Did I hear correctly that almost all "stars" that are visible with the naked eye at night are double star systems? For some reason, that took some of the fun out of looking up at night.

  • Why this is significant (Score:4, Informative)

    by radtea ( 464814 ) on Monday January 09, 2006 @06:03PM (#14431200)

    Cepheid variable stars are one of the most basic "standard candles" on which our measurement of interstellar distances depends. Polaris is one of the closest Cepheids.

    Cepheid periods depend on luminosity, but the period-luminosity relation is still semi-empirical. Knowing the mass of Polaris (which you can get from measuring the orbital elements of the companion star) pins down one of the important variables in the theoretical model of Cepheids, and so helps firm up one of the basic measuring instruments we use to determine the scale of the universe.

    In the past, there have been significant changes in our beliefs about the scale of the universe due to problems with interpretation of variable star data--the discovery that some presumed Cepheids were actually RR Lyrae variables changed things by about a factor of two, IIRC.

    Things are a lot better than that now, but it is still good to see that people are working to ensure our view of the universe is as consistent and accurate as possible.

  • aha... (Score:2, Funny)

    by d1rty_d0gg_ ( 875482 )
    Polaris is really a triple star system

    so this why Sun is still excited about PowerPC.
  • Apparently Polaris pissed off Chuck Norris...

    One good roundhouse kick was enough to dislodge Polaris Ab and set it in orbit.

    And don't even ask what happened to Polaris A.

  • We're missing the real news here (Score:5, Funny)

    by Jay L ( 74152 ) <jay+slash&jay,fm> on Monday January 09, 2006 @09:10PM (#14432392) Homepage
    astronomers have photographed the close companion of Polaris

    Waitaminute. Polaris is GAY?
  • The companion's distance from Polaris A makes me think of 2010 by Arthur C. Clarke, in which Jupiter ignites and becomes a small star.

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